Re: Installing an operating system on an 11/83

[Adrian Graham via cctalk]

> On 22 Feb 2022, at 14:01, Antonio Carlini via cctalk  
> wrote:
> 
> On 22/02/2022 03:27, Fred Cisin via cctalk wrote:
>> Are RX50 drives less robust than what was used to install Windoze 95?
> 
> 
> I never installed it this way myself, but MicroVMS on the MicroVAX II was 
> distributed on RX50 floppies: lost of them.
> 
> 
> Of course, that was then and the floppy drives were younger and less 
> temperamental (and perhaps the same could be said about the people feeding 
> the drives floppies ...)
> 

That didn't stop me being massively nervy installing a VMS v5.0 upgrade from 
RX50s to a customer's VAX 11/50... I think it was the first one that I'd done 
so no pressure.

-- 
Adrian Graham
Owner of Binary Dinosaurs, the UK's biggest private home computer collection?
t: @binarydinosaursf: facebook.com/binarydinosaurs
w: www.binarydinosaurs.co.uk

Re: Installing an operating system on an 11/83

[Adrian Graham via cctalk]

> On 22 Feb 2022, at 15:20, Antonio Carlini via cctalk  
> wrote:
> 
> On 22/02/2022 14:19, Adrian Graham via cctalk wrote:
>> That didn't stop me being massively nervy installing a VMS v5.0 upgrade from 
>> RX50s to a customer's VAX 11/50... I think it was the first one that I'd 
>> done so no pressure.
> 
> I remember doing the V5 upgrade on a VAX-11/750 but via tape. You still 
> needed to boot from TU58, which seemed to take roughly forever.
> 
> 
> I imagine it was possible to hook up RX50s to a VAX-11/750 but I never saw 
> one configured that way. Why not use tape :-)
> 

That's just what the request was. I suspect they didn't have a tape drive, the 
VAX was the only bit of DEC kit they had because the fixed drives were all 
Systems Industries. They probably did a disk backup for reasons. I know for a 
fact that the local failed circus engineers hated this particular site because 
most of the faults they went to work on were because of the SI drives which 
IIRC were Fuji/Eagle.

-- 
Adrian Graham
Owner of Binary Dinosaurs, the UK's biggest private home computer collection?
t: @binarydinosaursf: facebook.com/binarydinosaurs
w: www.binarydinosaurs.co.uk

Re: Tandon TM 848-02

[Adrian Graham via cctalk]

> On 24 Feb 2022, at 12:21, Bill Gunshannon via cctalk  
> wrote:
> 
> On 2/24/22 01:09, Mike Stein wrote:
>> P 1-17 of the Service Manual
> 
> What manual?  I understand the one on bitsavers is for the
> 848 and not the 848-02 which has a completely different logic
> board.  Have I been misinformed?


This is the one I have, it covers both -1 and -2 since they're the same board, 
only the number of heads is different.

https://binarydinosaurs.co.uk/TandonTM848ServiceGuide.pdf 


Cheers,

-- 
Adrian Graham
Owner of Binary Dinosaurs, the UK's biggest private home computer collection?
t: @binarydinosaursf: facebook.com/binarydinosaurs
w: www.binarydinosaurs.co.uk

Re: For Sale: STM Pied Piper "Portable Computer"

[Adrian Graham via cctalk]

On 24/03/2017 21:03, "Santo Nucifora"  wrote:

> What format are those disks in?  I did find the software and manuals but I
> have to image my disks too.  I have not used them yet and have never powered
> on my Pied Piper at this point.  I hope to image them this weekend (if they
> are still good).
> 
> Wish my Pied Piper was in better shape but I'm happy to have what I got. 
> Here's a link:  http://vintagecomputer.ca/stm-pied-piper-computer  You can see
> a pic of the manuals too.  I was considering scanning them but I'd have to
> tear them apart so I haven't.
> 
> Santo
> 
> On Fri, Mar 24, 2017 at 3:20 PM, Pete Plank via cctalk 
> wrote:
>> 
>>> >
>>> > I have several of these including the full disk set of 'Perfect'
>>> > applications and diagnostics, demo disk etc. One of my jobs for last year
>>> > was to image those disks but it took me so long to find them I never got
>>> one
>>> > of those tuits we all need.
>>> >
>>> > If anyone buys this let me know and I'll see what's still readable.
>> 
>> I have one as well in the original box with the external drive, manuals, etc.
>> but no disks - so I¹ve never had it fully running. If you could see what¹s
>> available that would be fantastic.
>> 
>> Thanks much!
> 
> 
> 
> Hi Santo, Pete,
> 
> I did email you (Santo) when I found them last year but I didn¹t get round to
> imaging them at the time. The win98 machine I built to do this is still where
> I left it in the kitchen so I¹m going to have a go tomorrow; the disks
> themselves have been indoors in a decent climate so hopefully they¹re all as I
> left them when I last read them in 2002.
> 
> I¹ve just realised how long ago that was :/ At least I know one of my Pied
> Piper floppy drives was ok because that was originally what I used in said
> win98 imaging machine 8 months ago.
> 
> Results as I get them!
> 
> Cheers

-- 
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?

PSU protection with resettable polyfuse

[Adrian Graham via cctalk]

Hi folks,

The PSU for my Executel 8085 system is an Astec AC8151-01 40W 5A unit that
puts out +5/+12/-12V. A while back somone suggested using an ATX PSU in its
place which TBH I'd forgotten about untl I saw a breakout board that you
plug a 20 or 24 pin ATX supply into and it terminates each rail in whatever
you choose to solder in. ukp8, rude not to :)

My only worry is an ATX PSU is capable of putting out a lot more than 5A if
it goes wrong so I'd like to protect each rail with an appropriate fuse.
Any downsides to resettable polyfuses?

Cheers,

-- 
adrian/witchy
Owner of Binary Dinosaurs, the UK's biggest home computer collection?
www.binarydinosaurs.co.uk

Re: PSU protection with resettable polyfuse

[Adrian Graham via cctalk]

On 29 March 2017 at 16:24, Systems Glitch  wrote:

> If you hit them hard enough, they'll sometimes permanently open, which is
> desirable anyway but does require rework. I don't remember how they stack
> up speed-wise, I'm sure it's in the datasheets.


I don't mind that, better rework that distribution than whatever's been
belted. I didn't know resettable fuses existed until I accidentally zapped
a Raspberry Pi by dragging it under my metal iMac. That's got a 2A polyfuse
and it was back in service 30 mins later.

-- 
adrian/witchy
Owner of Binary Dinosaurs, the UK's biggest home computer collection?
www.binarydinosaurs.co.uk

Re: HISTORY OF COMPUTER DESIGN: THE MOST INNOVATIVE AND UNCONVENTIONAL PCS EVER MADE

[Adrian Graham via cctalk]

On 03/04/2017 11:19, "cctalk"  wrote:

> This series of articles focuses mainly on physical design, of cases
> and so on, but there are some technical details in the articles too.
> 
> Note that this is the landing page -- at the bottom of the page are
> links to other articles in the Inexhibit series, such as the Holborn
> 9100 and Olivetti Programma 101.
> 
> https://www.inexhibit.com/specials/history-of-computer-design-the-most-innovat
> ive-and-unconventional-pcs-ever-made/

I just love the design of the Holborn series of machines, first time I saw
one I didn't believe it was a real machine...

-- 
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?

Re: Intellivision reset switch

[Adrian Graham via cctalk]

On 03/04/2017 22:38, "cctalk"  wrote:

> On Mon, Apr 3, 2017 at 10:16 AM, Richard Sheppard via cctalk <
> cctalk@classiccmp.org> wrote:
> 
>> 
>> May depend on the model, but mine has a spring under the plastic reset
>> button in the top of the case and one of those metal domed tactile switches
>> on the PCB.
>> 
> 
> This matches my recollection of the system I had. The type of metal domed
> switch made famous by the Atari 2600 joysticks.

I quickly read that and my brain said 'metal doomed switch', which I guess
was also correct :)

-- 
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?

Re: FTGH Large amount of DEC/Misc Classic computer hardware

[Adrian Graham via cctalk]

> On 7 May 2017, at 07:18, Rob Jarratt via cctalk  wrote:
> 
> A pity this is the wrong the side of the pond and shipping is so expensive, 
> otherwise I would love to get a 5000/240 or 5000/260 and some 5" drives.
> 
> Regards
> 
> Rob
> 

Hi Rob,

I’ve been told about reship.com who I guess are like a US equivalent of 
parcel2go over here. You pay domestic US shipping to them and they add a 
surcharge to forward it over to you, presumably by boat. What I don’t know is 
how that affects import duty etc but it might be worth looking into.

A

>> -Original Message-
>> From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Guy
>> Sotomayor Jr via cctalk
>> Sent: 07 May 2017 05:01
>> To: General Discussion: On-Topic and Off-Topic Posts 
>> Subject: Re: FTGH Large amount of DEC/Misc Classic computer hardware
>> 
>> I stopped by and picked up some stuff from Peter today.  There’s a lot of 
>> stuff
>> but I was only prepared to take a few items (I ended up taking a couple of 
>> tek
>> ‘scopes too).
>> 
>> I didn’t have time to sort through everything that was available but there’s 
>> a
>> lot!
>> 
>> He did mention that he has to be out of his space by May 31st and anything 
>> that
>> isn’t picked up will be scrapped.  I did take some pictures that I’ll put up
>> sometime tomorrow but what Pete has on his list below seems pretty accurate.
>> 
>> Pete is located in Richmond CA.  I can forward his contact information to
>> anyone that is interested in acquiring some/all of the remaining stuff.
>> 
>> TTFN - Guy
>> 
>>> On Mar 17, 2017, at 1:14 PM, Peter C. Wallace via cctalk
>>  wrote:
>>> 
>>> 
>>> Richmond CA (Hilltop business park)
>>> 
 
> On Mar 17, 2017, at 12:56 PM, Peter C. Wallace via cctalk
>>  wrote:
> 
> We need to move our business and I have about a ton of classic
> cimputer junk in the SFBA that need to go or get scrapped:
> 
> Many Decstations (3100, 5000/1xx and 5000/240/260s series even a
> 5100) many Vaxstations 3100s mostly Vax 4000 300?
> 5" DEC hard drives
> Many DEC mice
> Small Alphas
> Dec/HP  CRT monitors
> HP ~1990s Unix workstations and parts Versatec CE3000 plotter (huge)
> test equipment (misc Tek scopes and plugins mainly) Symbolics 3645?
> (from Guy Sotomayer a few years back) HP 2115? mini PDP 11 Couple 3
> KW UPSs with bad batterys
> SR22 calculator
> Altos 5 15
> etc
> 
> Would really like all to go to someone in the CC community who can take
>> all and sort/distribute themselves rather than cherry pick but that may be
>> optimistic...
> 
> 
> 
> Peter Wallace
> 
 
>>> 
>>> Peter Wallace
>>> Mesa Electronics
>>> 
>>> (\__/)
>>> (='.'=) This is Bunny. Copy and paste bunny into your
>>> (")_(") signature to help him gain world domination.
> 

Re: FTGH Large amount of DEC/Misc Classic computer hardware

[Adrian Graham via cctalk]

> On 7 May 2017, at 18:21, Rob Jarratt  wrote:
> 
>> I’ve been told about reship.com who I guess are like a US equivalent of
>> parcel2go over here. You pay domestic US shipping to them and they add a
>> surcharge to forward it over to you, presumably by boat. What I don’t know is
>> how that affects import duty etc but it might be worth looking into.
>> 
>> A
>> 
> 
> Interesting. I just checked the site. It looks to be mostly about giving you 
> a US mailing address, but then it just ships to you using a normal carrier 
> such as USPS, UPS, Fedex etc., so it doesn't seem likely that it would be a 
> cheaper way, or am I missing something?
> 

This is the reason I mentioned parcel2go - they send thousands of parcels daily 
so can negotiate a cheaper rate for shipping with the same companies thee and 
me use. I assume ReShip do the same thing.

Cheers

A

Re: I hadn't made the connection before

[Adrian Graham via cctalk]

On 2 June 2017 at 17:13, Cameron Kaiser via cctalk 
wrote:

> The (ridiculous) story of the Keyboard Component was legendary. The ECS
> keyboard variant can barely be considered functional even by the standards
> of the time, though I guess it at least looks decent compared to an
> Aquarius
> and the second sound chip was nice. It was designed to be cheap and get the
> FTC off Mattel's back and that's all it did.
>

I managed to get hold of an ECS in 2001-ish when there wasn't much info
around for it, hence my writeup here

http://binarydinosaurs.co.uk/museum/mattel/ecs/index.php

-- 
adrian/witchy
Owner of Binary Dinosaurs, the UK's biggest home computer collection?
www.binarydinosaurs.co.uk

More Executel phone system news

[Adrian Graham via cctalk]

Hi folks,

Some of you may remember me burning the midnight oil over an 8085-based phone 
system designed by STC in the UK, the Executel 3910. 

Good news to report! Completely by chance one of the programme managers for STC 
at the time found all my postings and pictures in a last ditch attempt to give 
his stash of goodies away before he put them all in the local recycling.

This means that not only do I now have two unused units and spare parts but I 
also have the machine that was dragged all over the world to trade shows, full 
documentation, a complete source dump AND the entire 8” disk set for an Intel 
MDS80 :D

A slight downside is that the code is all written in PLM which I’ve no 
experience in whatsoever.

Another downside is I now know what’s making my machine loop at startup. 
Remember the LUCY modem chip? Otherwise known as the SAA5070, my board is 
sending it an init code and expecting an ‘ok’ result back which it doesn’t get. 
At least I have 3 other spare chips now.

The final issue is that the unused machines have had their PSUs removed since 
the ASTEC 8151 was a bit of an achilles heel because of the way it was mounted 
upside down and only passively cooled, so I’m back on the trail of fixing the 
spare PSUs I have…

Fun times ahead!

—
Adrian/Witchy
Binary Dinosaurs - Celebrating Computing History from 1972 onwards

Re: More Executel phone system news

[Adrian Graham via cctalk]

> On 9 Jun 2017, at 15:14, Noel Chiappa via cctalk  
> wrote:
> 
>> From: Adrian Graham
> 
>> Completely by chance one of the programme managers for STC at the time
>> found all my postings ... in a last ditch attempt to give his stash of
>> goodies away before he put them all in the local recycling.
>> This means that not only do I now have two unused units and spare parts
>> but I also have .. full documentation, a complete source dump AND the
>> entire 8" disk set
> 
> Oh, that is _fantastic_ news. I'm so happy this was all saved.
> 

6 hour round trip, I drove home with a massive grin on my face.

>> Another downside is I now know what's making my machine loop at
>> startup.
> 
> Hey, the problem would be there whether or not you knew the cause - knowing
> the cause is surely better than not knowing!
> 

Oh true, and once I sort the power issue out and get RESET working properly on 
mine again I can swap out a LUCY from another machine to see if it makes a 
difference.

>> the ASTEC 8151 was a bit of an achilles heel because of the way it was
>> mounted upside down and only passively cooled
> 
> Any way (i.e. room) to add a small fan to help with the cooling? Sounds like
> that's definitely indicated…
> 

Externally yes, but the days of these machines being on 24x7 are long gone. 
While the PSTN is still there to dial numbers the viewdata side disappeared 
10-15 years ago though there’s a group of hardcore people trying to resurrect 
it on a more modern platform.

Interestingly one of Paul’s sons works in HVAC so might be able to cast an eye 
over the PSUs to see if they’re easily fixed.

—
Adrian/Witchy
Binary Dinosaurs - Celebrating Computing History from 1972 onwards

Re: Through-hole desoldering (was Re: IBM 5110 - Where does the character set live? And other questions.)

[Adrian Graham via cctalk]

> On 13 Jul 2017, at 22:46, Eric Smith via cctalk  wrote:
> 
> On Thu, Jul 13, 2017 at 10:42 AM, William Sudbrink via cctalk <
> cctalk@classiccmp.org> wrote:
> 
>> If you have the bucks, go for a Pace station with an SX-100 desoldering
>> tool.  40 pin chips
>> fall out like they were never soldered in the first place.
>> 
> 
> That's my experience with the Hakko 472D-01. Presumably the FR410-03 would
> work as well or better.

A couple of years ago I bought the UK-branded equivalent of the Zhongdi ZD-915 
desoldering station and I can quite honestly say it’s the best thing I’ve 
bought for this hobby/obsession. To anyone struggling with solder wick and 
manual pumps it’s worth far more in saved time than anything else. 

Spares are easy to get from Zhongdi in China and since they make the things 
themselves you can get any spare part you need.

—
Adrian/Witchy
Binary Dinosaurs - Celebrating Computing History from 1972 onwards

Re: Diskette size (was: Repurposed Art (ahem...)

[Adrian Graham via cctalk]

> On 21 Jul 2017, at 11:46, Liam Proven via cctalk  
> wrote:
> 
> I was aware of Twiggy disks, Hitachi 3" as used in Amstrad and Tatung,
> and of one that I think Fred _didn't_ mention: the 2" 720 kB diskettes
> used in the Zenith Minisport:
> 
> http://oldcomputers.net/zenith-minisport.html
> 
> ... but none of the rest.
> 
> We all know what 3.5" diskettes were called in South Africa, right?

Yep :)

I have a Facit9911 2 11/16” (or 70mm in new money) microfloppy drive with a 
mahoosive interface module which google turns up precisely nothing about. I’m 
pretty sure I’ve mentioned it here before but even a search of the archive 
turns up nothing.

See pic - http://www.binarydinosaurs.co.uk/facit9911MicroFloppy.jpg

—
Adrian/Witchy
Binary Dinosaurs - Celebrating Computing History from 1972 onwards

Re: What Is This Component?

[Adrian Graham via cctalk]

> On 23 Jul 2017, at 23:05, Rob Jarratt via cctalk  wrote
> I am trying to repair my DECstation 220 after a battery leak, and making
> some reasonable progress. I have reached a component that is unknown to me,
> so I don't know how it is supposed to behave. It is connected to the inputs
> of a CMOS NAND gate, where I measure a steady voltage of 1.8V, but the
> output of the gate is oscillating, which suggests to me that the gate can't
> decide what the input is. So perhaps this mystery component could be to
> blame. The marking on it is "KDS0B" (the zero could be an "oh", I am not
> sure). I have a spare board with the same component where there is a marking
> of "32768". Some searches suggest it might be an oscillator.
> 

It is, it’s a 32.768kHz oscillator for an RTC. I’ve got a few brand new ones in 
front of me as replacements for the battery-damaged crystal in the Executel I’m 
trying to resurrect.

It’ll cost me a stamp to send you one up if you need it.

Cheers

—
Adrian/Witchy
Binary Dinosaurs - Celebrating Computing History from 1972 onwards

Re: Generating macintosh disks

[Adrian Graham via cctalk]

> On 24 Jul 2017, at 07:30, Mattis Lind via cctalk  
> wrote:
> 
> måndag 24 juli 2017 skrev Alexandre Souza via cctalk > :
> 
>> Hi there!
>> 
>> Spent all saturday and sunday trying to boot a Mac Plus. Unfortunately I
>> hadn't any 800K boot disks nor a way to generate them.
>> 
>> I solved the problem using a Classic booting 7.0.1, writting a 7.0.1 1.4MB
>> disk on PC using winimage, loading this disk on the mac classic, copying
>> the contents of disk onto a zip disk and booting the mac plus with the zip.
>> 
>> My questions:
>> - Is there a Macintosh (in)PC emulator which can I read/write this zip
>> disc?
> 
> - Is there an easy way to connect the mac plus to a pc and transfer files?
> 
> 
> I am not sure that ther are easy ways around this. When I had this problem
> I used AppleTalk. I used a OrangePi as a netatalk server and a bridge
> between LocalTalk and EtherTalk. It requires that you installed LocalTalk
> SW on your MAC of course.

I’ve had several goes at this particularly when I was making 400k disks for my 
first Lisa. Back then it was:

download .sit from apple’s website (or later on use images from David T. 
Craig’s CDs)
copy to floppy then sneakernet to an LCII that had PCExchange installed
Appletalk over to a IIci (or IIcx, can’t remember) to write 400k disks

> I have written about it here.
> http://www.datormuseum.se/computers/apple/macintosh-plus
> 
> Another solution (which I haven't tried) is to use BMOW disk emulator.
> https://www.bigmessowires.com/floppy-emu/

I’d love one of those but can’t afford it for the little use it’ll get, though 
having said that I’ve recently spent the same amount on some SDcard adapters 
for my exhibition C64, BBC Model B and ZXSpectrum :)

Cheers

—
Adrian/Witchy
Binary Dinosaurs - Celebrating Computing History from 1972 onwards

Re: eBay: RL02 packs, UK

[Adrian Graham via cctalk]

> On 29 Jul 2017, at 21:54, Noel Chiappa via cctalk  
> wrote:
> 
> Lot of 6; UK only, I think
> 
>  http://www.ebay.com/itm/253056726492
> 
>   Noel

I don’t need any more but it’s nice to see the shockwatch hasn’t gone on any of 
them.

A


—
Adrian/Witchy
Binary Dinosaurs - Celebrating Computing History from 1972 onwards

ftp.compaq.com mirror

[Adrian Graham via cctalk]

Hi folks,

Managed to rescue a Compaq Deskpro EN from the scrap pile at work today and 
realised it has a proper floppy controller so I can install a 5.25” drive.

Trouble is ftp.compaq.com  has disappeared so getting 
drivers for win98 is going to be difficult unless I have them at work on old 
driver CDs. archive.org  has a mirror of the whole ftp 
site but it’s 220gb and I’m not sure my little 150mb/s web connection will 
download that in less than a month :)

Did anyone else grab it before it disappeared?

cheers,

—
Adrian/Witchy
Binary Dinosaurs - Celebrating Computing History from 1972 onwards

Re: ftp.compaq.com mirror

[Adrian Graham via cctalk]

> On 8 Aug 2017, at 20:30, Eric Christopherson via cctalk 
>  wrote:
> 
> On Tue, Aug 8, 2017 at 2:19 PM, Adrian Graham via cctalk <
> cctalk@classiccmp.org> wrote:
> 
>> Hi folks,
>> 
>> Managed to rescue a Compaq Deskpro EN from the scrap pile at work today
>> and realised it has a proper floppy controller so I can install a 5.25”
>> drive.
>> 
>> Trouble is ftp.compaq.com <http://ftp.compaq.com/> has disappeared so
>> getting drivers for win98 is going to be difficult unless I have them at
>> work on old driver CDs. archive.org <http://archive.org/> has a mirror of
>> the whole ftp site but it’s 220gb and I’m not sure my little 150mb/s web
>> connection will download that in less than a month :)
>> 
>> Did anyone else grab it before it disappeared?
>> 
> 
> I've found it at
> http://web.archive.org/web/20051120074512/http://ftp.compaq.com:80/ -- and
> that allows you to descend into subdirectories just like on a real FTP site

I think my ISP was having a brain fart a couple of hours ago because I couldn’t 
ftp to ftp.compaq.com and can now, I’m browsing away happily. Technology eh!

> I'm guessing the one-file download you mentioned was at
> https://archive.org/details/ftp.compaq.com. That page offers a torrent,
> which gives you another way of downloading either the whole thing or just
> parts: you can open that torrent file in a decent BitTorrent client but,
> instead of starting to download the whole thing, go into the list of files
> included and just check off the ones you want to download and keep the rest
> excluded.
> 
> 

Yes, but my view of it said there were no browseable files which was the point 
I asked here. I’ll put it down to Virgin Media/Libery Global cocking something 
up somewhere just for a change

Cheers!

>> 
>> cheers,
>> 
>> —
>> Adrian/Witchy
>> Binary Dinosaurs - Celebrating Computing History from 1972 onwards
>> 
>> 
> 
> 
> -- 
>Eric Christopherson

Re: This Is Such An Exciting Listing!

[Adrian Graham via cctalk]

> On 19 Aug 2017, at 00:13, Rob Jarratt via cctalk  
> wrote:
> 
> http://www.ebay.co.uk/itm/182707649701
> 
> 
> 

It doesn’t beat a listing from 15 or so years ago from a mate of mine who 
advertised a polo mint (lifesavers to our US types) in a clear case as ‘mint in 
box (mint, in box)'


—
Adrian/Witchy
Binary Dinosaurs - Celebrating Computing History from 1972 onwards

Atari PSU with collapsing 5V rail

[Adrian Graham via cctalk]

Hi folks,

I think I’ve mentioned this PSU before but the question I have might be 
applicable to other cheap switchers. This lump for the original Atari 520ST is 
run by an NE5561N control chip with a D45H1 switching transistor. It’s supplied 
by a multi-tap transformer giving 2x2 feeds of 6VAC and 14VAC with an eventual 
output of 5V@3A, 12V@30mA, -12V@30mA.

This one will run under load for around 10 minutes then the 5V rail will 
gradually collapse over the next few minutes. Turn it off and leave for a 
minute or so and it’s back to normal, repeat as above.

Unfortunately there’s no schematic online but I’ve done a mix photo of the 
control circuits:

http://www.binarydinosaurs.co.uk/atariPSU1Hybrid.jpg 
 

The 4700uF cap in the centre is on the output stage so I changed that yesterday 
which just makes the eventual collapse longer.

Could the actual transformer lump break down over time and recover that 
quickly? Its 6VAC outputs do go a bit erratic. Also I measured the GAIN input 
on the NE5561N pin 4 and during the collapse it goes over twice what it is when 
the 5V rail is stable (7V instead of around 3.4V). I have another running 
supply to measure against.

Any clues appreciated. It’d be nice to feed the 6VAC input from another source 
but I’m not sure my VARIAC will go that low.

—
Adrian/Witchy
Binary Dinosaurs - Celebrating Computing History from 1972 onwards

Re: Atari PSU with collapsing 5V rail

[Adrian Graham via cctalk]

> On 20 Aug 2017, at 16:32, Mattis Lind  wrote:
> 
> 
> 
> söndag 20 augusti 2017 skrev Adrian Graham via cctalk  <mailto:cctalk@classiccmp.org>>:
> Hi folks,
> 
> I think I’ve mentioned this PSU before but the question I have might be 
> applicable to other cheap switchers. This lump for the original Atari 520ST 
> is run by an NE5561N control chip with a D45H1 switching transistor. It’s 
> supplied by a multi-tap transformer giving 2x2 feeds of 6VAC and 14VAC with 
> an eventual output of 5V@3A, 12V@30mA, -12V@30mA.
> 
> This one will run under load for around 10 minutes then the 5V rail will 
> gradually collapse over the next few minutes. Turn it off and leave for a 
> minute or so and it’s back to normal, repeat as above.
> 
> Heat related?  Try freeze spray to check if it recovers or stays working 
> longer. 

I need to jury rig something with a breadboard to allow me to run it outside 
the enclosure, in normal usage it’s solder side up with the components covered. 
I can’t remove the transformer lump because it’s sealed in resin. They really 
didn’t want people to attempt to fix these things :)


—
Adrian/Witchy
Binary Dinosaurs - Celebrating Computing History from 1972 onwards

Re: Atari PSU with collapsing 5V rail

[Adrian Graham via cctalk]

>> 
>> Any clues appreciated. It’d be nice to feed the 6VAC input from another 
>> source but I’m not sure my VARIAC will go that low.
> 
> 
> The gain pin is presenting the output of the error amplifier, an increase 
> there is what you would expect as the output V falls, as the difference 
> between the ref and target V increases.
> It's 'trying harder' to raise the output V to correct the error.
> It implies that the reference and the error amplifier are functioning.

OK, I can see that.

> 
> "6VAC outputs do go a bit erratic" is not a helpful description.

I thought they dropped continually but they’re just constantly adjusting around 
6VAC. Annoyingly I’ve just run the whole system for the last 40 minutes and 
while the troublesome supply has dipped below 5V at times it hasn’t collapsed. 
I’ve been formatting floppies, copying files between floppies and rebooting. 
Only now has floppy access started to fail at 4.8V but the machine itself still 
runs. Screen output flickers though, but nothing catastrophic like the other 
day.

> 
> A wide range of stepdown transformers  .. 8V, 10V, 12V, 18V, 24V ..  could be 
> used in conjunction with your variac to get 6VAC for an alternate feed.
> 
> If you have a variable DC supply of adequate current you can feed approx. 6V 
> * 1.4 = 8.4VDC into the 6VAC input instead.
> 

I’ve got a couple of 5A bench supplies if necessary.

> Is the failure load-level (current-draw) related?:
>   Does the out V remain stable if the supply is unloaded or very lightly 
> loaded?
>   Does it take longer to drop at a lesser load?
> If so it's likely thermal-related.

V out is stable with no load, as soon as the ST is turned off. I could use it 
to run the floppy drive but that’s such a low load I don’t think it would cause 
failure. Worth a try I guess.

> Is anything heating up unduly?
> 

I can’t tell without the aforementioned jury-rigging extra wiring, in normal 
usage it looks like this - http://www.binarydinosaurs.co.uk/atariSTPSU-2.jpg

Cheers!

—
Adrian/Witchy
Binary Dinosaurs - Celebrating Computing History from 1972 onwards

Re: Atari PSU with collapsing 5V rail

[Adrian Graham via cctalk]

> On 20 Aug 2017, at 23:20, Chuck Guzis via cctalk  
> wrote:
> 
> On 08/20/2017 12:12 PM, Brent Hilpert via cctalk wrote:
> 
>> If the transformer were faulty and heating up internally, it would seem 
>> unlikely that it would cool off that quickly to recover, IME it takes some 
>> time for a transformer to cool off.
> 
> I have an open-frame linear PSU that started behaving that way.  Turned
> out to be a current-sense resistor with a bad internal connection.  As
> things warmed up, the resistance would rise until the current overload
> IC kicked it and shut things down.   It was pretty frustrating because
> the entire time, the output looked pretty stable.
> 
> I don't know if that's what's going on here, however.

There’s only 10 resistors in the whole PSU so it wouldn’t take long to replace 
them all. The problem could very well be thermal, today hasn’t been as warm as 
last week when I was testing it to shutdown. Freeze spray would hopefully 
confirm that.

Cheers,

—
Adrian/Witchy
Binary Dinosaurs - Celebrating Computing History from 1972 onwards

Re: Atari PSU with collapsing 5V rail

[Adrian Graham via cctalk]

> On 20 Aug 2017, at 23:20, Chuck Guzis via cctalk  
> wrote:
> 
> On 08/20/2017 12:12 PM, Brent Hilpert via cctalk wrote:
> 
>> If the transformer were faulty and heating up internally, it would seem 
>> unlikely that it would cool off that quickly to recover, IME it takes some 
>> time for a transformer to cool off.
> 
> I have an open-frame linear PSU that started behaving that way.  Turned
> out to be a current-sense resistor with a bad internal connection.  As
> things warmed up, the resistance would rise until the current overload
> IC kicked it and shut things down.   It was pretty frustrating because
> the entire time, the output looked pretty stable.

Chuck wins some 16-bit air, or I suppose technically 16/32 bit air. I changed 
the reference resistors to the NE5561N and the PSU is now stable, no picture 
drift on the monitor and the 5V rail doesn’t move from 5.4V. If I could send an 
e-beer I would :)

http://www.binarydinosaurs.co.uk/atariSTPSUfixed.jpg

(dodgy disk in the A drive there, it’s currently running Bubble Bobble)


—
Adrian/Witchy
Binary Dinosaurs - Celebrating Computing History from 1972 onwards

Re: Atari PSU with collapsing 5V rail

[Adrian Graham via cctalk]

> On 20 Aug 2017, at 23:20, Chuck Guzis via cctalk  
> wrote:
> 
> On 08/20/2017 12:12 PM, Brent Hilpert via cctalk wrote:
> 
>> If the transformer were faulty and heating up internally, it would seem 
>> unlikely that it would cool off that quickly to recover, IME it takes some 
>> time for a transformer to cool off.
> 
> I have an open-frame linear PSU that started behaving that way.  Turned
> out to be a current-sense resistor with a bad internal connection.  As
> things warmed up, the resistance would rise until the current overload
> IC kicked it and shut things down.   It was pretty frustrating because
> the entire time, the output looked pretty stable.

Dammit. Spoke too soon. The machine ran for over an hour happily Bubble 
Bobbling so I swapped the disk for Super Sprint and 5V started disappearing on 
me. I turned it off for a minute and it came back to life and ran for another 
few minutes steady at 5.4V again. 

Back to jury-rigging I guess.

—
Adrian/Witchy
Binary Dinosaurs - Celebrating Computing History from 1972 onwards

A little power circuit explanation please

[Adrian Graham via cctalk]

Hi folks,

Failing Atari PSU aside I remembered a question I had ages ago but never posted 
about the power circuit of another 80s home micro, the Enterprise 64. This 
machine is powered by a 2A 9V unregulated PSU and internally there’s a pair of 
7805s and a 78L12 to smooth things out. 

There’s also a small transformer coil in there too (L1 on the following 
schematic) and I’m not entirely sure what it’s for. Here’s the schematic of the 
original circuit, any enlightenment gratefully received since I have an 
Enterprise 64 with a dead coil :)

http://www.binarydinosaurs.co.uk/ep64PowerRegulators.png 
 

Cheers!

—
Adrian/Witchy
Binary Dinosaurs - Celebrating Computing History from 1972 onwards

Re: Wanted: small composite CRT monitor

[Adrian Graham via cctalk]

> 
> In short, I'm looking for a small NTSC CRT monitor or portable TV in
> the 7-12" range. I'm not stuck on aesthetics, but it would be nice to
> have something that would sit nicely atop the IIc. I wouldn't mind an
> actual Apple monitor, but I don't want to pay APPLE MAC IPHONE STEVE
> JOBS L@@K prices; otherwise, I'd be happy with any suitable composite
> video monitor, color or monochrome. If you happen to be within
> reasonable driving distance of Folsom, CA, I'd be glad to pick it up
> and save the trouble of shipping. Anybody got one to spare?

Late last year I picked up a Sony PVM-9041QM 9” ex-broadcast monitor for not 
much money at all, it sits nicely on top of an Apple ][ and looks excellent 
with a pair of Disk][s stacked next to it. There MUST be TV studios around your 
area pretty much throwing these out these days.

Cheers

—
Adrian/Witchy
Binary Dinosaurs - Celebrating Computing History from 1972 onwards

Re: A little power circuit explanation please

[Adrian Graham via cctalk]

> On 23 Aug 2017, at 00:45, Don North via cctalk  wrote:
> 
> On 8/22/2017 4:30 PM, Adrian Graham via cctalk wrote:
>> Hi folks,
>> 
>> Failing Atari PSU aside I remembered a question I had ages ago but never 
>> posted about the power circuit of another 80s home micro, the Enterprise 64. 
>> This machine is powered by a 2A 9V unregulated PSU and internally there’s a 
>> pair of 7805s and a 78L12 to smooth things out.
>> 
>> There’s also a small transformer coil in there too (L1 on the following 
>> schematic) and I’m not entirely sure what it’s for. Here’s the schematic of 
>> the original circuit, any enlightenment gratefully received since I have an 
>> Enterprise 64 with a dead coil :)
>> 
>> http://www.binarydinosaurs.co.uk/ep64PowerRegulators.png 
>> <http://www.binarydinosaurs.co.uk/ep64PowerRegulators.png>
>> 
>> Cheers!
>> 
>> —
>> Adrian/Witchy
>> Binary Dinosaurs - Celebrating Computing History from 1972 onwards
>> 
>> 
> It is part of a switching power supply to boost the 9VDC input to 13.7V or 
> greater so that the 78L12 can regulate it down to 12V.
> 
> L1 is dual purpose; it provides feedback to the boost switching regulator 
> oscillator (the tap) and is the main inductor for the boost supply generator.

Thanks for that Don, having re-read my original question I’m kicking myself for 
not spotting the whole ‘9V input’ thing. *sigh*.

Cheers!

—
Adrian/Witchy
Binary Dinosaurs - Celebrating Computing History from 1972 onwards

Re: A little power circuit explanation please

[Adrian Graham via cctalk]

> On 23 Aug 2017, at 00:49, Rob Doyle via cctalk  wrote:
> 
> It's a little switching power supply.  It steps up the 9V input voltage to 
> something a few volts greater than 12V to feed the 12V regulator.
> 
> If your 12V is correct, it is probably working.
> 

This is from 2 months ago but I was puzzling over the 12V circuit in this 
particular machine and also maybe suffering from a red herring since the PSU I 
was using is from a ZXSpectrum+2 which is an unregulated 12-14V lump so the 
coil was already being fed 12V.

A 

> Rob.
> 
> On 8/22/2017 4:30 PM, Adrian Graham via cctalk wrote:
>> Hi folks,
>> Failing Atari PSU aside I remembered a question I had ages ago but never 
>> posted about the power circuit of another 80s home micro, the Enterprise 64. 
>> This machine is powered by a 2A 9V unregulated PSU and internally there’s a 
>> pair of 7805s and a 78L12 to smooth things out.
>> There’s also a small transformer coil in there too (L1 on the following 
>> schematic) and I’m not entirely sure what it’s for. Here’s the schematic of 
>> the original circuit, any enlightenment gratefully received since I have an 
>> Enterprise 64 with a dead coil :)
>> http://www.binarydinosaurs.co.uk/ep64PowerRegulators.png 
>> <http://www.binarydinosaurs.co.uk/ep64PowerRegulators.png>
>> Cheers!
>> —
>> Adrian/Witchy
>> Binary Dinosaurs - Celebrating Computing History from 1972 onwards
> 

Re: A little power circuit explanation please

[Adrian Graham via cctalk]

> On 23 Aug 2017, at 15:07, dwight  wrote:
> 
> 
> The regulator needs about 2.5 to 3 volts head room. The circuit is what is 
> often called a boost circuit. If my calculations are right, it should produce 
> about 15.5 to 16V on C10. This gives the regulator enough over voltage to 
> work as a regulator. If the supply you have is not regulated it won't be able 
> to be used directly.
> TR2 and L1 transformer form an oscillator. When TR2 conducts, it causes a 
> field to build up in L1. When TR2 turns off, the field in L1 tries to 
> collapse. The voltage build up until the diode conducts charging C10. This is 
> often called fly-back. Coils like to keep conducting at a constant rate. 
> Since TR2 turns off, the coils voltage will continue to rise until it finds a 
> path to send the current ( the diode ).
> When the voltage gets high enough across the resistor divider, R16/R15, TR3 
> turns off. This removes the bias needed to turn on TR2, shutting down the 
> oscillation.
> If the voltage on C10 drops to the point that TR3 conducts, the oscillation 
> will start again, boosting the voltage on C10 again.
> Dwight

That’s brilliant, thanks Dwight! 

—
Adrian/Witchy
Binary Dinosaurs - Celebrating Computing History from 1972 onwards


> 
> From: cctalk  <mailto:cctalk-boun...@classiccmp.org>> on behalf of Adrian Graham via cctalk 
> mailto:cctalk@classiccmp.org>>
> Sent: Wednesday, August 23, 2017 12:33:44 AM
> To: General Discussion: On-Topic and Off-Topic Posts
> Subject: Re: A little power circuit explanation please
>  
> 
> > On 23 Aug 2017, at 00:49, Rob Doyle via cctalk  > <mailto:cctalk@classiccmp.org>> wrote:
> > 
> > It's a little switching power supply.  It steps up the 9V input voltage to 
> > something a few volts greater than 12V to feed the 12V regulator.
> > 
> > If your 12V is correct, it is probably working.
> > 
> 
> This is from 2 months ago but I was puzzling over the 12V circuit in this 
> particular machine and also maybe suffering from a red herring since the PSU 
> I was using is from a ZXSpectrum+2 which is an unregulated 12-14V lump so the 
> coil was already being fed 12V.
> 
> A 
> 
> > Rob.
> > 
> > On 8/22/2017 4:30 PM, Adrian Graham via cctalk wrote:
> >> Hi folks,
> >> Failing Atari PSU aside I remembered a question I had ages ago but never 
> >> posted about the power circuit of another 80s home micro, the Enterprise 
> >> 64. This machine is powered by a 2A 9V unregulated PSU and internally 
> >> there’s a pair of 7805s and a 78L12 to smooth things out.
> >> There’s also a small transformer coil in there too (L1 on the following 
> >> schematic) and I’m not entirely sure what it’s for. Here’s the schematic 
> >> of the original circuit, any enlightenment gratefully received since I 
> >> have an Enterprise 64 with a dead coil :)
> >> http://www.binarydinosaurs.co.uk/ep64PowerRegulators.png 
> >> <http://www.binarydinosaurs.co.uk/ep64PowerRegulators.png>
> <http://www.binarydinosaurs.co.uk/ep64PowerRegulators.png 
> <http://www.binarydinosaurs.co.uk/ep64PowerRegulators.png>
> >
> >> Cheers!
> >> —
> >> Adrian/Witchy
> >> Binary Dinosaurs - Celebrating Computing History from 1972 onwards
> > 
> 

Re: C64 to VGA

[Adrian Graham via cctalk]

> On 28 Aug 2017, at 02:30, Kevin Parker via cctalk  
> wrote:
> 
> HI guys - not really a C64 person (I've been given a couple over the years 
> and kept them rather than see them go to landfill).
> 
> Trying to fix one up for a very good friend for a house warming present for 
> his games room (he said something the other day that
> gave me the hint).
> 
> I have a genuine Commodore monitor but don't want to give him that but I have 
> bucket loads of VGA (LCD) monitors I've scored over
> time as well so thought I'd use one of those.
> 
> I've googled het subject a lot but there seems to be lots of options and 
> views on what works and what doesn't and even how well.
> 
> I'd be most grateful if anyone on the list has any advice, suggestions, 
> recommendations etc about this.

I made up an S-VHS cable for mine then feed that into either an LCD TV that has 
an S-VHS input or a VGA converter. The only trouble with the converters is 
there seems to be two different chipsets in the Chinese ones and YMMV a lot, 
for instance this one works:

http://www.ebay.co.uk/itm/Composite-S-video-BNC-To-VGA-Converter-Adapter-VGA-Cable-For-PC-LCD-CCTV-Camera-/132296519532

while this one doesn’t

http://www.ebay.co.uk/itm/EU-Yellow-Composite-RCA-SVHS-to-VGA-Converter-Adapter-CCTV-Analogue-/263047471571

—
Adrian/Witchy
Binary Dinosaurs - Celebrating Computing History from 1972 onwards

Re: Update: Rehoming Apple ][+ , BBC B+?? & A410/1 with math co-processor - Liverpool UK

[Adrian Graham via cctalk]

> On 2 Sep 2017, at 20:21, Dave Wade via cctalk  wrote:
> 
> Folks
> I got this today via my Vintage Computing Meetup groups. If there is any 
> interest please contact Nick direct
> Dave

Typically I was supposed to be near Liverpool tonight but the customer 
cancelled the job, grr.

Not that I NEED another ][+ and Beeb+ but, you know….

A


> -Original Message-
> From: Nik Kelly [mailto:nik.ke...@blueyonder.co.uk] 
> Sent: 02 September 2017 17:33
> To: Dave Wade 
> Subject: Re: Update: Rehoming Apple ][+ , BBC B+?? & A410/1 with math 
> co-processor
> 
> Where-ever, Dave !
> 
> Nik
> 
> On 02/09/2017 13:44, Dave Wade wrote:
>> Nik,
>>  Do you mind if I publish elsewhere? CCTALK mail list? Vintage Computing 
>> forums?
>> Dave
>> 
>>> -Original Message-
>>> From: Nik Kelly [mailto:nik.ke...@blueyonder.co.uk]
>>> Sent: 02 September 2017 13:16
>>> To: dave.g4...@gmail.com; off...@madlab.org.uk
>>> Subject: Update: Rehoming Apple ][+ , BBC B+?? & A410/1 with math co- 
>>> processor
>>> 
>>> Hi !
>>> 
>>> I've now collated those boxes & crates.
>>> Approx 5' x 4' x 18" ~~ 30 cu feet ~~ one cubic metre.
>>> 
>>> All free to good home ASAP...
>>> I cannot deliver, taker(s) must collect.
>>> Would you pass the word around your members ??
>>> Nik
>>> 
>>> 
>>>  Forwarded Message 
>>> Subject: Rehoming Apple ][+ , BBC B+?? & A410/1 with math 
>>> co-processor
>>> Date: Mon, 21 Aug 2017 12:02:55 +0100
>>> From: Nik Kelly 
>>> To: dave.g4...@gmail.com
>>> 
>>> Hi, Dave !
>>> 
>>> Due to forthcoming down-size, I must re-home my three vintage computers.
>>> 
>>> Apple ][+ 48k, floppy drive and accessories from 1979, NOT PRODOS.
>>> BBC B+ {+ 64/128 ??} & 5.25" floppy drives, Acorn A410/1 with math 
>>> co- processor, hard drive & floppy interface.
>>> 
>>> They're in original crates, with sundry manuals, reference books etc.
>>> Also *multiple* crates of my disks and tapes etc. Very few games.
>>> 
>>> ** Due care required for old capacitors etc. ** The Apple ][+ and BBC 
>>> have been packed away, not run since ~1990, the
>>> A410/1 since I switched to PCs in ~2001.
>>> 
>>> I used to write for MicroDigital's 'Liverpool Software Gazette'.
>>> Remember 'Stargate-- A 3D Planetarium' ? The ApplePips column ??
>>> 
>>> Anyhow, I'm still based in Liverpool. I'd hoped to do some 
>>> retro-computing but that's now become impracticable.
>>> 
>>> The three have minimal commercial value, so are FREE to good home.
>>> 
>>> There's no rush, their crates are buried in box-room; I'll have to 
>>> clear access, collate accessories, check other rooms for strays.
>>> 
>>> Would you pass the word around your members ??
>>> I cannot deliver, taker(s) must collect.
>>> 
>>> Thank you.
>>> Nik
>>> 
>>> ps: Some of my short stories and fun cat piccies may be found at...
>>> https://the-nik-files.deviantart.com/
>> 
>> 
> 

Re: Does anyone recognise this please

[Adrian Graham via cctalk]

> On 3 Sep 2017, at 08:02, drlegendre . via cctalk  
> wrote:
> 
> Err.. I've seen it, I know it.. trying to place it.
> 
> Commodore VIC-20?

That was my first thought too. I only have UK ones so don’t have the channel 
selector switch but the casing is the same.

A

(sent from the correct account this time, apologies if it double posts)

> On Sun, Sep 3, 2017 at 1:40 AM, Kevin Parker via cctalk <
> cctalk@classiccmp.org> wrote:
> 
>> Found this in a box of stuff I was given. Looks brand new. It's obviously
>> a RF Modulator of some type but I can't tell exactly what
>> it's for or designed for. One end has a number 251083-03 and the other end
>> has a switch for CH0 and CH1. The DIN plug is 5 pin.
>> 
>> 
>> 
>> I Googled the number and found some reference on http://www.
>> yesterdaystechnology.com/ which confirms it's a RF Modulator but nothing
>> else.
>> 
>> 
>> 
>> Photos are here.
>> 
>> 
>> 
>> http://koken.advancedimaging.com.au/index.php?/albums/
>> f54fbe61f7978530b1dbd08eca0bc80f/content/e3ceacd632dcac82255081e611941fc0/
>> 
>> 
>> 
>> Thank you!!
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> Kevin Parker
>> 
>> P: 0418 815 527
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 

—
Adrian/Witchy
Binary Dinosaurs - Celebrating Computing History from 1972 onwards

Re: Does anyone recognise this please

[Adrian Graham via cctalk]

> On 3 Sep 2017, at 08:02, drlegendre . via cctalk  
> wrote:
> 
> Err.. I've seen it, I know it.. trying to place it.
> 
> Commodore VIC-20?

That was my first thought too. I only have UK ones so don’t have the channel 
selector switch but the casing is the same.

A


> On Sun, Sep 3, 2017 at 1:40 AM, Kevin Parker via cctalk <
> cctalk@classiccmp.org> wrote:
> 
>> Found this in a box of stuff I was given. Looks brand new. It's obviously
>> a RF Modulator of some type but I can't tell exactly what
>> it's for or designed for. One end has a number 251083-03 and the other end
>> has a switch for CH0 and CH1. The DIN plug is 5 pin.
>> 
>> 
>> 
>> I Googled the number and found some reference on http://www.
>> yesterdaystechnology.com/ which confirms it's a RF Modulator but nothing
>> else.
>> 
>> 
>> 
>> Photos are here.
>> 
>> 
>> 
>> http://koken.advancedimaging.com.au/index.php?/albums/
>> f54fbe61f7978530b1dbd08eca0bc80f/content/e3ceacd632dcac82255081e611941fc0/
>> 
>> 
>> 
>> Thank you!!
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> Kevin Parker
>> 
>> P: 0418 815 527
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 

Re: VCF Midwest: 6502 Badges!

[Adrian Graham via cctalk]

> On 8 Sep 2017, at 21:11, Jim Brain via cctalk  wrote:
> 
> As the proud owner (and builder) of said badge, I recorded my build, in case 
> anyone cares.  Only 1 mistake :-)
> 
> It's a long build, done late at night (so liesurely pace), and I deviated a 
> bit from the build instructions, so take with a pinch of salt.
> 
> https://www.youtube.com/watch?v=lMdghJnc7vM&feature=youtu.be
> 

Nice to put a face and voice to a name I’ve known for many years! Must buy one 
of those kits before it’s too late, pity the display part seems to only be 
available from one US site since I have most of the other bits needed, hey ho.

Cheers

Adrian

> Jim
> 
> -- 
> Jim Brain
> br...@jbrain.com
> www.jbrain.com
> 

—
Adrian/Witchy
Binary Dinosaurs - Celebrating Computing History from 1972 onwards

Z80 micro screen colour inversion

[Adrian Graham via cctalk]

Hi folks,

I’ve been troubleshooting another one of “uncle” Clive Sinclair’s offspring 
(though most folk don’t know his involvement), the Grundy Newbrain. It’s a 
typical early 80s micro with Z80 and 32K RAM made up of 16x 4116 DRAM.

What’s uncommon with this particular one is that it works….mostly. The annoying 
thing with the fault with this one is that I watched it happen - the whole 
screen is inverted so instead of white-on-black I now get black-on-white with 
garbled characters.

Initially the display was fine but with the rightmost line of pixels missing 
from each character so I suspected the character ROM (2332 mask PROM) or 
74LS166 bit shifter that supports it, but then as I watched the whole screen 
inverted and stayed that way, see pics.

I’ve attached the schematic of the board, but for now my general question is 
what could cause the whole video stream to be inverted? ISTR that with the ZX80 
you could invert the screen with a jumper that switched output from a 74LS165 
bit shifter from the Q to /Q pins but the 74LS166 doesn’t have an inverted 
output, unless I’m reading the datasheet wrongly of course :)

http://www.binarydinosaurs.co.uk/newbrain-05.jpg 

http://www.binarydinosaurs.co.uk/newbrain-14.jpg 

http://www.binarydinosaurs.co.uk/newbrain.pdf 


Cheers!

—
Adrian/Witchy
Binary Dinosaurs - Celebrating Computing History from 1972 onwards

Re: Z80 micro screen colour inversion

[Adrian Graham via cctalk]

>>On schematic pdf.pg4, what looks to be the video pixel stream SOVSR (from
IC436 on pdf.pg3) feeds an OR gate of IC433, thence inverter in >>IC450,
XOR in IC434, combined with some other stuff in OR gate IC464, resistive
mixing with the composite sync CMSNC, to produce the >>composite video
CMPVD.

>>The XOR of IC434 is the point of interest, the state of the other input
of that XOR gate will invert-or-not the pixel stream.
>>It is labeled as being fed from RVF (ReVerse Field or Frame?).

>>I haven't looked at the schematic long enough to find the source of RVF.
Hardware configuration? Bit of an IO port from software configuration?

>>But I don't know, going from your pic isn't their a lot more screwed up
than just reversed video?

Hi Brent,

It's nice to know my musings last night were on the right track with IC434.
I'd traced the signal back from the composite out and found SOVSR
(embarrassingly I didn't work out that CMPVD could mean Composite Video)
and decided that RVF must be a reverse video signal. RVF comes from IC426
(LS86) which uses a signal called RF as a source. RF comes from IC427
(LS174 flip-flop) pin 15, the input for that is pin 14 (A0).

However, the clock for IC427 is missing and THAT comes from pin 12 of IC430
(LS138) whic is marked TVTL.

I didn't get any further than that.

Cheers!

On 25 September 2017 at 09:48, Brent Hilpert via cctalk <
cctalk@classiccmp.org> wrote:

> On 2017-Sep-25, at 12:42 AM, Adrian Graham via cctalk wrote:
> > I’ve been troubleshooting another one of “uncle” Clive Sinclair’s
> offspring (though most folk don’t know his involvement), the Grundy
> Newbrain. It’s a typical early 80s micro with Z80 and 32K RAM made up of
> 16x 4116 DRAM.
> >
> > What’s uncommon with this particular one is that it works….mostly. The
> annoying thing with the fault with this one is that I watched it happen -
> the whole screen is inverted so instead of white-on-black I now get
> black-on-white with garbled characters.
> >
> > Initially the display was fine but with the rightmost line of pixels
> missing from each character so I suspected the character ROM (2332 mask
> PROM) or 74LS166 bit shifter that supports it, but then as I watched the
> whole screen inverted and stayed that way, see pics.
> >
> > I’ve attached the schematic of the board, but for now my general
> question is what could cause the whole video stream to be inverted? ISTR
> that with the ZX80 you could invert the screen with a jumper that switched
> output from a 74LS165 bit shifter from the Q to /Q pins but the 74LS166
> doesn’t have an inverted output, unless I’m reading the datasheet wrongly
> of course :)
> >
> > http://www.binarydinosaurs.co.uk/newbrain-05.jpg <
> http://www.binarydinosaurs.co.uk/newbrain-05.jpg>
> > http://www.binarydinosaurs.co.uk/newbrain-14.jpg <
> http://www.binarydinosaurs.co.uk/newbrain-14.jpg>
> > http://www.binarydinosaurs.co.uk/newbrain.pdf <
> http://www.binarydinosaurs.co.uk/newbrain.pdf>
>
>
> Howzabout:
>
> On schematic pdf.pg4, what looks to be the video pixel stream SOVSR (from
> IC436 on pdf.pg3) feeds an OR gate of IC433, thence inverter in IC450, XOR
> in IC434, combined with some other stuff in OR gate IC464, resistive mixing
> with the composite sync CMSNC, to produce the composite video CMPVD.
>
> The XOR of IC434 is the point of interest, the state of the other input of
> that XOR gate will invert-or-not the pixel stream.
> It is labeled as being fed from RVF (ReVerse Field or Frame?).
>
> I haven't looked at the schematic long enough to find the source of RVF.
> Hardware configuration? Bit of an IO port from software configuration?
>
> But I don't know, going from your pic isn't their a lot more screwed up
> than just reversed video?
>
>


-- 
adrian/witchy
Owner of Binary Dinosaurs, the UK's biggest home computer collection?
www.binarydinosaurs.co.uk

Strange grounding problem

[Adrian Graham via cctalk]

Hi folks,

This is another Grundy Newbrain problem on a different machine that is probably 
easily explained by someone who understands current flow. This machine has two 
startup circuits that are simply a resistor and 10uF capacitor each, both 
feeding a Hex Schmitt Trigger (CD401068CM). When the caps have charged up 
sufficiently they activate both PWRUP and RESET signals one after the other 
thanks to the 220K and 560K resistors.

Schematic for the circuits is here - 
http://www.binarydinosaurs.co.uk/newbrainPowerupCircuits.png 
 - top circuit is 
PWRUP and the bottom one is RESET that goes straight to the Z80.

Only in this machine it doesn’t unless I have 3 sampling probes and a GND probe 
on my USB-powered logic analyser attached to pins 3-5 of the CD401068CM and the 
GND pin of any nearby chip. Less than 3 sampling probes and it won’t start so 
those probes must be facilitating current flow to GND?

Cheers!

PS Brent, I got the other Newbrain going by replacing the 74LS166 shift 
register, the one that provides the SOVSR signal. All good now!

—
Adrian/Witchy
Binary Dinosaurs - Celebrating Computing History from 1972 onwards

Re: Strange grounding problem

[Adrian Graham via cctalk]

> On 28 Sep 2017, at 03:47, dwight  wrote:
> 
> Were does the powerup signal go?
> Dwight

Hi Dwight,

It goes to the output control (pin 15) of an LS257, the outputs of which look 
to be chiefly in charge of ROM selection via an LS138, schematic here: 
http://www.binarydinosaurs.co.uk/newbrainPWRUPSchematic.png 
<http://www.binarydinosaurs.co.uk/newbrainPWRUPSchematic.png>

Looks like it’s giving a few seconds delay for everything to power up cleanly.

A

> 
> From: cctalk  <mailto:cctalk-boun...@classiccmp.org>> on behalf of Adrian Graham via cctalk 
> mailto:cctalk@classiccmp.org>>
> Sent: Wednesday, September 27, 2017 5:23:45 PM
> To: General Discussion: On-Topic and Off-Topic Posts
> Subject: Strange grounding problem
>  
> Hi folks,
> 
> This is another Grundy Newbrain problem on a different machine that is 
> probably easily explained by someone who understands current flow. This 
> machine has two startup circuits that are simply a resistor and 10uF 
> capacitor each, both feeding a Hex Schmitt Trigger (CD401068CM). When the 
> caps have charged up sufficiently they activate both PWRUP and RESET signals 
> one after the other thanks to the 220K and 560K resistors.
> 
> Schematic for the circuits is here - 
> http://www.binarydinosaurs.co.uk/newbrainPowerupCircuits.png 
> <http://www.binarydinosaurs.co.uk/newbrainPowerupCircuits.png><http://www.binarydinosaurs.co.uk/newbrainPowerupCircuits.png
>  <http://www.binarydinosaurs.co.uk/newbrainPowerupCircuits.png>> - top 
> circuit is PWRUP and the bottom one is RESET that goes straight to the Z80.
> 
> Only in this machine it doesn’t unless I have 3 sampling probes and a GND 
> probe on my USB-powered logic analyser attached to pins 3-5 of the CD401068CM 
> and the GND pin of any nearby chip. Less than 3 sampling probes and it won’t 
> start so those probes must be facilitating current flow to GND?
> 
> Cheers!
> 
> PS Brent, I got the other Newbrain going by replacing the 74LS166 shift 
> register, the one that provides the SOVSR signal. All good now!
> 
> —
> Adrian/Witchy
> Binary Dinosaurs - Celebrating Computing History from 1972 onwards
> 

Re: Strange grounding problem

[Adrian Graham via cctalk]

Hi all,

I removed the CD401068CM and capacitors and made up an identical startup 
circuit on a breadboard with a pair of LEDs and it worked fine, 3 second delay 
for ‘reset’ (yellow LED) and another 3 second delay for ‘pwrup’ (red LED). Just 
before reassembly I noticed the holes on the board for the PWRUP cap were dirty 
so I cleaned that and the surrounding area off with IPA and soldered everything 
back in.

It works! It only reports 16K RAM though so there’s a fault in bank 1, I’ll 
deal with that later.

Thanks for the pointers :)

—
Adrian/Witchy
Binary Dinosaurs - Celebrating Computing History from 1972 onwards

> On 28 Sep 2017, at 03:08, Jerry Weiss  wrote:
> 
>> On Sep 27, 2017, at 8:14 PM, Charles Dickman via cctalk 
>>  wrote:
>> 
>> On Wed, Sep 27, 2017 at 8:23 PM, Adrian Graham via cctalk
>>  wrote:
>> 
>>> Schematic for the circuits is here - 
>>> http://www.binarydinosaurs.co.uk/newbrainPowerupCircuits.png 
>>> <http://www.binarydinosaurs.co.uk/newbrainPowerupCircuits.png> - top 
>>> circuit is PWRUP and the bottom one is RESET that goes straight to the Z80.
>>> 
>> 
>> CD4000 logic can't handle inputs pulled above the power pin or below
>> the ground pin without the possibility of malfunctioning or even
>> complete failure. Google for "CD4000 parasitic SCR" or "CMOS
>> latch-up". When power is cycled rapidly, the caps will still have
>> charge which could cause the latch-up. I did some industrial control
>> designs with CD4000 and used similar timing circuits, but always
>> included diodes to prevent inputs from being driven too high or too
>> low. I would have put diodes across both of the resistors.
>> 
>> Adding your probes may change the currents inside the chip that change
>> the latch-up behavior. Of course it also only makes sense if the power
>> is cycled quickly for some value of quickly. Others may have an
>> explanation, but that was my first thought from looking at the
>> schematic.
>> 
>> -chuck
> 
> The capacitors may have become leaky, and start to as resistors in the 100K 
> ohms range.
> 
> If so, the circuit now contains a voltage divider and and not meet the 
> threshold needed for 
> the logic gate to switch.  The probes have their own resistive component and 
> thus
> shift the other side of the divider, which puts the signal back into a 
> functional range for
> the Schmitt Trigger.
> 
> Jerry
> 
> 
> 

Re: cctalk Digest, Vol 39, Issue 2

[Adrian Graham via cctalk]

Hi Andrea,

I assume that's a message for me about my strange grounding issue?

I'd already replaced the caps in that startup circuit, it's one of the
first things you do when troubleshooting a non-booting Newbrain. In this
case it seemed to be some electrolytic spill from the original leaky caps
that I'd missed when cleaning the first time - the traces for this circuit
are on top of the board and I'd only cleaned the solder side.

Cheers :)

Adrian

On 29 September 2017 at 13:07, shad via cctalk 
wrote:

> Hello,
> explanation is easy.
> Old electrolytic will have a bigger current leakage, i.e. the unwanted
> amount of current which flows through it.
> With resistances having high value, the small current is completely eated
> by the leakage, thus never charging the capacitors.
> As you are connecting the probes, each having around 1M ohm impedance, you
> are lowering the effective resistance, thus charging a little.
>
> Solution: replace both capacitors with same value.
>
> Andrea
>



-- 
adrian/witchy
Owner of Binary Dinosaurs, the UK's biggest home computer collection?
www.binarydinosaurs.co.uk

Looking for anyone who may have Commodore 65 info

[Adrian Graham via cctalk]

Hi folks,

I realise this is a question that's only applicable to a small number of
people but I'm looking for anyone who may have info or better still PAL
dumps of a Rev3 C65. Back when I got the machine in 2001 there was a couple
of people active in this field, namely Riccardo Rubini and Moise Sunda.

Before I contact every hit that comes up on a google search does anyone
have an up to date email address for either of these people? I've already
talked to CBM luminaries Bo Zimmerman and Cameron Kaiser who are in the
same situation as me with a lack of up to date info.

Any help appreciated!

-- 
adrian/witchy
Owner of Binary Dinosaurs, the UK's biggest home computer collection?
www.binarydinosaurs.co.uk
facebook.com/binarydinosaurs

Re: Did DEC make a Daisy Wheel printer?

[Adrian Graham via cctalk]

> On 8 Oct 2017, at 18:19, Zane Healy via cctalk  wrote:
> 
> Did DEC make any sort of impact printer, besides dot-matrix printers?  I have 
> an LA50 or two, and dot-matrix isn’t what I’m after.

My brain is telling me LQP02 so yes, a daisywheel. I’ve not seen one for 30 
years or so though.


—
Adrian/Witchy
Binary Dinosaurs - Celebrating Computing History from 1972 onwards

Re: Did DEC make a Daisy Wheel printer?

[Adrian Graham via cctalk]

> On 8 Oct 2017, at 19:00, Jon Elson via cctalk  wrote:
> 
> On 10/08/2017 12:31 PM, Chuck Guzis via cctalk wrote:
>> On 10/08/2017 10:19 AM, Zane Healy via cctalk wrote:
>>> Did DEC make any sort of impact printer, besides dot-matrix printers?  I 
>>> have an LA50 or two, and dot-matrix isn’t what I’m after.
>> You mean like the LQP03 or LQP45?   I don't know if DEC made the basic
>> mechanism, however.
>> 
>> --Chuck
>> 
>> 
> I'm sure DEC did NOT make the actual wheel motor assembly.  Qume and Diablo 
> were the two biggies in that arena.
> Probably because of patents and copyrights, you couldn't just make compatible 
> daisy wheel font wheels, either.

Well yes, it was a Qume 1220. DEC didn’t make an awful lot of stuff outside of 
the actual PDP/VAX area.

A

Re: HEXTIr - TI HexBus SD Drive

[Adrian Graham via cctalk]

> On 29 Oct 2017, at 17:14, Jim Brain via cctalk  wrote:
> 
> In case anyone has a fondness for niche tech...
> 
> At VCF-SE this year, the TI folks had a great exhibit, and perusing it I saw 
> an unfamiliar machine, the TI CC-40 (Compact Computer-40).  While I was 
> investigating, the exhibitor (MillipedeMan aka Mark), told me the machines 
> were frustrating to use, as TI only supported one communications method on 
> the unit, a proprietary protocol called HexBus, and produced very low 
> quantities of very few peripherals that work on the bus. Most frustratingly, 
> they never producing a mass storage device in any appreciable quantity, and 
> there was no other way to save programs written on the unit.
> 
> Mark did note there was an eBay seller liquidating units, so I bought a 2 
> unit combo from eBay before I left the show.
> 
> Sadly, Summer happened, but I was finally able to get to the unit, and 
> started working on an SD-based mass storage device for the unit.  It was an 
> interesting journey to learn a new protocol.
> 
> The (development in progress) result is HEX-TI-r, the HexBus SD drive:
> 
> GitHub source code is here: https://github.com/go4retro/HEXTIr
> 
> Video of unit operating: https://www.youtube.com/watch?v=LX5ahVCRdvM
> 
> I don't have a project page up yet, but will work on that.

Wow! Many years ago I bought a CC-40 on ebay for pennies, boxed NOS. I forgot 
about it for over a decade and found it again recently looking for other 
things, this could be an excuse to get it out and see if it still works :)

Cheers,

—
Adrian/Witchy
Binary Dinosaurs - Celebrating Computing History from 1972 onwards

DECwriter II available for pickup in Gosport, Hants, UK

[Adrian Graham via cctalk]

Hi folks,

As the subject says. It's been stored in a garage for many years but is in
pretty good condition. Free for pickup.

Cheers,

-- 
adrian/witchy
Owner of Binary Dinosaurs, the UK's biggest home computer collection?
www.binarydinosaurs.co.uk

Re: H7861 PSU issues

[Adrian Graham via cctalk]

>I was also quite surprised that such a simple component would die,
>and what I find more confusing is that it died while I was using
>the machine.

A 555 can also take a Commodore PET down because it's solely in charge of
the RESET circuit, and no RESET == no PET.

On 2 November 2017 at 14:22, Aaron Jackson via cctalk  wrote:

> Thanks! It was very satisfying and not the worst thing to go wrong
> for a beginner.
>
> I was also quite surprised that such a simple component would die,
> and what I find more confusing is that it died while I was using
> the machine.
>
> Aaron.
>
> Noel Chiappa via cctalk  wrote:
>
> > > From: Aaron Jackson
> >
> > > Picked up a few 555s and sockets and now it works!
> >
> > Congratulations!
> >
> > It's odd that a 555 failed, but sometimes there's no rhyme or reason to
> what
> > fails. E.g. I was fixing some broken M7859's (KY11-LB Programmer's
> Console),
> > and on one of them a 7493 (4-bit counter) had died. That's not one of the
> > 'problem' 74xx chips, like ISTR the 7474 being?
> >
> >   Noel
>



-- 
adrian/witchy
Owner of Binary Dinosaurs, the UK's biggest home computer collection?
www.binarydinosaurs.co.uk

Re: looking at buying a pocket PC / PDA

[Adrian Graham via cctalk]

> On 3 Nov 2017, at 23:21, Liam Proven via cctalk  wrote:
> 
> On 3 November 2017 at 22:53, Fred Cisin via cctalk
>  wrote:
> 
>> Exactly!
>> 
>> But, they sometimes try to convince us that it means "Personal Computer
>> Memory Card Instustry Association", which is far less credible
> 
> OK, next, for 2 points. What does TWAIN stand for? No conferring or
> consulting research materials.
> 

OK I’ll bite. Toolkit Without An Indicated Name.

(my early noughties scanners proclaimed this proudly)

> -- 
> Liam Proven • Profile: https://about.me/liamproven
> Email: lpro...@cix.co.uk • Google Mail/Talk/Plus: lpro...@gmail.com
> Twitter/Facebook/Flickr: lproven • Skype/LinkedIn/AIM/Yahoo: liamproven
> UK: +44 7939-087884 • ČR/WhatsApp/Telegram/Signal: +420 702 829 053

TRS80 Model 4P CRT contrast fail

[Adrian Graham via cctalk]

Hi folks,

A random facebook post made me dig out my model 4P which has never worked as 
long as I’ve owned it, it’s always just sat on a shelf looking cute. 

Good old ASTEC PSU problem so I fixed that, reseated all the thankfully 
socketed chips and it burst into life. Sort of. I know it’s running because I 
can turn the brightness up to raster lines and see the pattern actually change 
when RESET is pressed. With contrast right up I can JUST see the boot logo 
appear while it reads the floppy.

None of the pots on the video board deal with contrast so I’ve got it out on 
the bench to remove and test the capacitors. What else can I look at at the 
same time? Someone else has already mentioned the transistors Q101, Q102 and 
Q103 (on the yoke board).

Screen pic: http://www.binarydinosaurs.co.uk/trs80Model4PScreen.jpg 
 - you can JUST see 
the boot logo, I know it’s not screen burn because it does disappear on RESET 
and comes back again.

Video board schematic: 
http://www.binarydinosaurs.co.uk/trs80Model4PVideoBoardSchematic.png 
 

Cheers!

—
Adrian/Witchy
Binary Dinosaurs - Celebrating Computing History from 1972 onwards

Re: TRS80 Model 4P CRT contrast fail

[Adrian Graham via cctalk]

> On 23 Nov 2017, at 21:18, Brent Hilpert via cctalk  
> wrote:
> 
> On 2017-Nov-23, at 11:34 AM, Adrian Graham via cctalk wrote:
>> Hi folks,
>> 
>> A random facebook post made me dig out my model 4P which has never worked as 
>> long as I’ve owned it, it’s always just sat on a shelf looking cute. 
>> 
>> Good old ASTEC PSU problem so I fixed that, reseated all the thankfully 
>> socketed chips and it burst into life. Sort of. I know it’s running because 
>> I can turn the brightness up to raster lines and see the pattern actually 
>> change when RESET is pressed. With contrast right up I can JUST see the boot 
>> logo appear while it reads the floppy.
>> 
>> None of the pots on the video board deal with contrast so I’ve got it out on 
>> the bench to remove and test the capacitors. What else can I look at at the 
>> same time? Someone else has already mentioned the transistors Q101, Q102 and 
>> Q103 (on the yoke board).
>> 
>> Screen pic: http://www.binarydinosaurs.co.uk/trs80Model4PScreen.jpg 
>> <http://www.binarydinosaurs.co.uk/trs80Model4PScreen.jpg> - you can JUST see 
>> the boot logo, I know it’s not screen burn because it does disappear on 
>> RESET and comes back again.
>> 
>> Video board schematic: 
>> http://www.binarydinosaurs.co.uk/trs80Model4PVideoBoardSchematic.png 
>> <http://www.binarydinosaurs.co.uk/trs80Model4PVideoBoardSchematic.png> 
> 
> 
> You might check the contrast control.
> I can't find the actual schematic for the contrast control connections, but I 
> 'm guessing the ends are connected across 12V (video board pins 5 & 1/4/10) 
> and the wiper to video board pin 8.
> The contrast control can be expected to take pin 8 somewhere + to get pixels 
> fully on.

You’re right with pin 8, tracing the circuit I can see why someone recommended 
I check Q101 and Q102 which look OK in my tester. The contrast control itself 
tests OK resistance wise, it goes from pretty much 0ohms to 610M.

> Or get back to us with some voltage measurements at the BCE of TR101, 2 and 
> 3, and at the external connections to the little board on the end of the CRT.
> Note that there will (should) be several hundred volts on some of those CRT 
> board connections.
> 
> Does the "internal brightness" control on the video board have some effect?

Yes, it works with the external control. It was the first thing I checked last 
night.

Cheers

A

Re: TRS80 Model 4P CRT contrast fail

[Adrian Graham via cctalk]

> On 23 Nov 2017, at 20:43, Chuck Guzis via cctalk  
> wrote:
> 
> On 11/23/2017 11:34 AM, Adrian Graham via cctalk wrote:
> 
>> None of the pots on the video board deal with contrast so I’ve got it out on 
>> the bench to remove and test the capacitors. What else can I look at at the 
>> same time? Someone else has already mentioned the transistors Q101, Q102 and 
>> Q103 (on the yoke board).
> 
> Have you tried replacing C101?  What happens if you temporarily remove
> TR101?
> 

It tests ok at 4816nF with 1.4ohms ESR. I need to work out a way of getting 
everything connected together outside the case so I can do measurements. I’m 
hoping it’s something fairly easy to spot as high voltage even at low current 
is daunting.

Cheers

A

Re: TRS80 Model 4P CRT contrast fail

[Adrian Graham via cctalk]

> On 24 Nov 2017, at 17:23, Tony Duell via cctalk  wrote:
> 
> On Fri, Nov 24, 2017 at 8:41 AM, Brent Hilpert via cctalk
>  wrote:
>> On 2017-Nov-23, at 5:07 PM, Adrian Graham via cctalk wrote:
>>>> On 23 Nov 2017, at 21:18, Brent Hilpert via cctalk  
>>>> wrote:
>>>> ...
>>>> You might check the contrast control.
>>>> I can't find the actual schematic for the contrast control connections, 
>>>> but I 'm guessing the ends are connected across 12V (video board pins 5 & 
>>>> 1/4/10) and the wiper to video board pin 8.
>>>> The contrast control can be expected to take pin 8 somewhere + to get 
>>>> pixels fully on.
>>> 
>>> You’re right with pin 8, tracing the circuit I can see why someone 
>>> recommended I check Q101 and Q102 which look OK in my tester.
>>> The contrast control itself tests OK resistance wise, it goes from pretty 
>>> much 0ohms to 610M.
>> 
>> 610M ?
>> I hope that M is a typo.
> 
> Indeed...
> 
> I am working from the Model 4P service manual which I downloaded from
> archive.org I
> think. I can't find a schematic for the control panel, but the parts
> list says the 2
> pots are 500 Ohms (contrast) and 500k brightness. One of diagrams at
> the start of
> the manual suggests the former has 3 wires (wired as a potentiometer),
> the latter
> 2 (wired as a variable resistor).

Yep, see my correction this morning. Just checked it again and it’s 0-641ohms.

> I am assuming the fault is correctly described, a lack of contrast and not
> brightness. Can you get a bright raster if you turn the brightness control up?

Yep, that’s how I can *just* see the boot logo. 

> OK... Firstly, measure the voltage on pin 8 of the monitor PCB. Can you get
> it to swing from 0 to around 12V?

I’ll have to partially reassemble out of the case to test, but I can get to the 
other end of pin 8 with the control panel removed.

> Scope the video output from the CPU board (on pin 2 of the monitor PCB). Is
> it a good TTL level signal?

Good point.

> 
> Measure the voltage on pin A of the CRT base PCB. Expect around 60V here.
> 
> Check that C101 is not shorted. You could try the machine with it removed
> to see what happens.

I removed it and tested it last night, looks OK.

> Have you checked the TR103 on the CRT base PCB?

Not yet, sleep was more important at that point :) 

I’ll report back tomorrow, cheers!

—
Adrian/Witchy
Binary Dinosaurs - Celebrating Computing History from 1972 onwards

Re: TRS80 Model 4P CRT contrast fail

[Adrian Graham via cctalk]

> On 24 Nov 2017, at 08:41, Brent Hilpert via cctalk  
> wrote:
> 
> On 2017-Nov-23, at 5:07 PM, Adrian Graham via cctalk wrote:
>>> On 23 Nov 2017, at 21:18, Brent Hilpert via cctalk  
>>> wrote:
>>> ...
>>> You might check the contrast control.
>>> I can't find the actual schematic for the contrast control connections, but 
>>> I 'm guessing the ends are connected across 12V (video board pins 5 & 
>>> 1/4/10) and the wiper to video board pin 8.
>>> The contrast control can be expected to take pin 8 somewhere + to get 
>>> pixels fully on.
>> 
>> You’re right with pin 8, tracing the circuit I can see why someone 
>> recommended I check Q101 and Q102 which look OK in my tester.
>> The contrast control itself tests OK resistance wise, it goes from pretty 
>> much 0ohms to 610M.
> 
> 610M ?
> I hope that M is a typo.
> 

Morning!

It is, 610k or 0.6M :)

Cheers

A

Re: TRS80 Model 4P CRT contrast fail

[Adrian Graham via cctalk]

> On 24 Nov 2017, at 08:44, Adrian Graham via cctalk  
> wrote:
> 
> 
>> On 24 Nov 2017, at 08:41, Brent Hilpert via cctalk  
>> wrote:
>> 
>> On 2017-Nov-23, at 5:07 PM, Adrian Graham via cctalk wrote:
>>>> On 23 Nov 2017, at 21:18, Brent Hilpert via cctalk  
>>>> wrote:
>>>> ...
>>>> You might check the contrast control.
>>>> I can't find the actual schematic for the contrast control connections, 
>>>> but I 'm guessing the ends are connected across 12V (video board pins 5 & 
>>>> 1/4/10) and the wiper to video board pin 8.
>>>> The contrast control can be expected to take pin 8 somewhere + to get 
>>>> pixels fully on.
>>> 
>>> You’re right with pin 8, tracing the circuit I can see why someone 
>>> recommended I check Q101 and Q102 which look OK in my tester.
>>> The contrast control itself tests OK resistance wise, it goes from pretty 
>>> much 0ohms to 610M.
>> 
>> 610M ?
>> I hope that M is a typo.
>> 
> 
> Morning!
> 
> It is, 610k or 0.6M :)
> 

Gah, ignore this. 

—
Adrian/Witchy
Binary Dinosaurs - Celebrating Computing History from 1972 onwards

Re: TRS80 Model 4P CRT contrast fail

[Adrian Graham via cctalk]

Evening!

> OK... Firstly, measure the voltage on pin 8 of the monitor PCB. Can you get
> it to swing from 0 to around 12V?

Yes, it tops out at 11.82V.

> Scope the video output from the CPU board (on pin 2 of the monitor PCB). Is
> it a good TTL level signal?

Yes. Given that it’s TTL and a 3-wire connection (composite plus H&V sync) I 
should be able to feed that into a PET monitor shouldn’t I? Wish I hadn’t given 
away my ‘big’ TRS80 Model 4 :/

> Measure the voltage on pin A of the CRT base PCB. Expect around 60V here

60.3V

> Check that C101 is not shorted. You could try the machine with it removed
> to see what happens.
> 
> Have you checked the TR103 on the CRT base PCB?

It tests as 2 diodes which is correct for a bipolar transistor I believe.

Cheers Tony,

A

Re: TRS80 Model 4P CRT contrast fail

[Adrian Graham via cctalk]

> On 26 Nov 2017, at 06:15, Tony Duell  wrote:
> 
> On Sat, Nov 25, 2017 at 11:02 PM, Adrian Graham via cctalk
>  wrote:
>> Evening!
>> 
>>> OK... Firstly, measure the voltage on pin 8 of the monitor PCB. Can you get
>>> it to swing from 0 to around 12V?
>> 
>> Yes, it tops out at 11.82V.
> 
> Can you get it down to 0V?

Yep, it runs from 0-11.82V.

>> 
>>> Scope the video output from the CPU board (on pin 2 of the monitor PCB). Is
>>> it a good TTL level
>>> signal?
>> 
>> Yes. Given that it’s TTL and a 3-wire connection (composite plus H&V sync) I
> 
> You mean 'video', not 'composite'. Composite is an analogue signal with the
> video information and the syncs all combined

Indeed. My brain was saying ‘video’ but my fingers typed ‘composite’ :)

>> should be able to feed that into a PET monitor shouldn’t I? Wish I hadn’t 
>> given
>> away my ‘big’ TRS80 Model 4 :/
> 
> I have no idea if the sync polarities are right, but you can try it with a Pet
> monitor. A TRS80 Model 3 has the same monitor as the Model 4 of course.

I’ll make up an extension cable I think, got more PETs than I know what to do 
with. I used to have multiple Model 3s AND a Model 2 but they had to go when I 
moved to a smaller house back in 2010.

> (And I wish I could find a 4P over here….)

Perhaps embarrassingly I can’t remember where mine came from but given I’ve had 
it since the early noughties that’s not surprising. It may even have been from 
a car boot sale.

> 
> What happens if C101 is removed? Also try running it with TR101
> removed (or at least the emitter lead of that transistor disconnected).

Nothing happens, in that the picture is the same as it is with both those 
components fitted.

Cheers

A

Re: TRS80 Model 4P CRT contrast fail

[Adrian Graham via cctalk]

> On 26 Nov 2017, at 19:31, Brent Hilpert via cctalk  
> wrote:
> 
> 
> With a scope the objective would be to look at the levels when pixels are 
> 'on' in the video signal.
> For white/on pixels, you need conductivity through TR102.E-C and TR103.E-C,
> to allow electrons to flow from GND, through those transistors, into the 
> cathode of the CRT,
> and be emitted from the cathode towards the screen.
> 
> For a white pixel then:
>   - the video signal (and to a lesser level, the base of TR102) must be 
> going positive, to turn TR102 on.
>   - TR103 collector should be going 'lower' during the pixel period, the 
> black level is approx. 60 V,
> the white level should drop well below that.
> 
> You probably won't see much voltage variation at CRT PCB point H / TR102.C / 
> TR103.E
> as it's just current-switching there with no collector pull-up.
> 
> You could try connecting CRT PCB point H briefly to GND through a 150-300 ohm 
> R, or short TR102.C-E (not 103).
> That should bring up a white screen.
> If it doesn't it would suggest the problem is around TR103.
> If it does the problem is likely around TR102.

I replied to this thread a while back but managed to only reply to Tony and not 
the list, oops! Rather than using my multi-transistor tester for TR103 I tested 
it with a DMM in diode mode and it’s almost a dead short from B-E, I get the 
same reading in both directions so I’m going to order a new one in a bit.

> If your multimeter has an hfe mode, you could try pulling TR102 & 103 and see 
> if they show gain.

It does but the legs on TR103 weren’t long enough to reach the contacts in the 
BCE holes which is why I went for diode mode instead :)

Thanks for the explanation, if the new transistor doesn’t make a difference 
then I know where else I can look.

Cheers!

—
Adrian/Witchy
Binary Dinosaurs - Celebrating Computing History from 1972 onwards

Re: TRS80 Model 4P CRT contrast fail

[Adrian Graham via cctalk]

> On 26 Nov 2017, at 21:06, Adrian Graham  wrote:
> 
> I replied to this thread a while back but managed to only reply to Tony and 
> not the list, oops! Rather than using my multi-transistor tester for TR103 I 
> tested it with a DMM in diode mode and it’s almost a dead short from B-E, I 
> get the same reading in both directions so I’m going to order a new one in a 
> bit.

Replying to myself here but to my surprise the replacement 2SC2228 arrived 
today and the machine is running nicely now, albeit with some screen wobble. I 
also tested the replacement in my transistor tester and it was correctly 
identified as a BJT NPN so I should’ve questioned it at the beginning but hey. 
Live and learn.

It’s currently running the built-in RAM test which is a lot more than it’s done 
for the last 15 years :)

Cheers folks!

> —
> Adrian/Witchy
> Binary Dinosaurs - Celebrating Computing History from 1972 onwards
> 

TRS80 Model 1 video RAM (2102A)

[Adrian Graham via cctalk]

Hi folks,

After sorting out the Model 4P (thanks to all who provided hints!) and 
scrubbing it up so it almost looks new again I turned attention to my Model 1 
Level II which had been dead for at least the same amount of time as the Model 
4. There’s some excellent troubleshooting tips for these machines out there and 
I quickly discovered a bad RAM chip, swap that for a NOS one and we’d be back 
in business if the video RAM wasn’t failing.

One of the 4 2102A chips is failing (MEM SIZE becomes OEO SIZE) and I’d like to 
double check this before I stump up the ukp4 required for a pair of NOS ones, 
can anyone think of a machine from back then that also used 2102A or 2102LPFC 
or NTE2102 video RAM?

Cheers!

—
Adrian/Witchy
Binary Dinosaurs - Celebrating Computing History from 1972 onwards

Canon BN22 Laptop manual, anyone?

[Adrian Graham via cctalk]

Hi folks,

I’ve been contacted by someone looking for the user guide for this particular 
beast, an early 90s mono laptop with built-in printer. The usual searches turn 
up nothing other than pictures and she says she’s found a PDF but in German.

Any clues?

—
Adrian/Witchy
Binary Dinosaurs - Celebrating Computing History from 1972 onwards

Re: Picked up beige Mac G3

[Adrian Graham via cctalk]

> On 11 Dec 2017, at 23:18, devin davison via cctalk  
> wrote:
> 
> Someone just dropped off a mac g3 at the scrapyard I work at and I picked it 
> up.
> It has a failing hard drive. Replaced the drive, downloaded and burned
> a disk with mac os 8 on it, but it refuses to boot to it. How do I go
> about installing the software on this machine?
> 
> Not sure if this is the place to ask, but figured it would be worth a
> shot. Thanks.

Hi Devin,

Going from memory you need to press ‘C’ to boot from CD and you might also need 
to replace the PRAM battery.

Cheers

—
Adrian/Witchy
Binary Dinosaurs - Celebrating Computing History from 1972 onwards
binarydinosaurs.co.uk
facebook.com/binarydinosaurs

ISO Intertec 5.25" floppy drive jumper settings

[Adrian Graham via cctalk]

Hi folks,

In my long ongoing quest to image and otherwise copy the hard sectored floppies 
with my Exidy Sorcerer I’m trying to find other floppy drives I can use with it 
since I don’t like relying on just one set of drives. I have a Cumana dual 
drive set that came with my TRS80 Model1 that I thought might be jumperable to 
300rpm, indeed I can see drive activity if I try and boot.

Does anyone know where I might find the/a manual for the drives? They’re marked 
as Intertec 5002040 so I’ve been all over Superbrain docs and PDFs on bitsavers 
but haven’t found anything so far.

Cheers!

-- 
adrian/witchy
Owner of Binary Dinosaurs, the UK's biggest private home computer collection?
t: @binarydinosaursf: facebook.com/binarydinosaurs
w: www.binarydinosaurs.co.uk

Re: ISO Intertec 5.25" floppy drive jumper settings

[Adrian Graham via cctalk]

Hi Fred,

> On 2 Dec 2018, at 23:32, Fred Cisin via cctalk  wrote:
> 
> On Sun, 2 Dec 2018, Adrian Graham via cctalk wrote:
>> In my long ongoing quest to image and otherwise copy the hard sectored 
>> floppies with my Exidy Sorcerer I’m trying to find other floppy drives I can 
>> use with it since I don’t like relying on just one set of drives. I have a 
>> Cumana dual drive set that came with my TRS80 Model1 that I thought might be 
>> jumperable to 300rpm, indeed I can see drive activity if I try and boot.
> 
> If those were being used on a TRS80 Model1, then they are already 300RPM.

I should’ve known that.

> When they went to 400K 40 cylinder MFM DSDD / double sided, double density, 
> still 48 tpi (like the PC-DOS 360K), they chose to call that "QD" / "QUAD 
> DENSITY"!! ?!??   (equating "density" with capacity)
> WHOA! Everybody else called THAT DSDD "Double Sided Double Density", and used 
> "QD" / "Quad Density" to refer to 80 cylinder Double density 96tpi!

So I’ve been reading :) I’m sure they weren’t doing it deliberately, hahaha.

> field on the sectors on the second side, but would accept disks with correct 
> headers.
> I have heard that they used a Z80 for floppy control, but the disks are 
> consistent with a Western Digital 179x controller.

They were always touted as twin-Z80 machines. I’ve always wanted one because 
when all I had at school was a Research Machines 380Z (another twin drive CP/M 
machine) the Superbrain LOOKED like a computer even though as I’ve been reading 
tonight it was originally designed as a terminal.

> I doubt that they manufactured their own disk drives, but it is possible. 
> Look carefully at the drives for any hints of who actually made them.
> Are these "full height" (SA400) or "half height”?

You’re right. Normally with Cumana stuff I do look for a manufacturer because 
yes, they were known to me as makers of repackaged drives for the Acorn BBC 
Micro. In this case the Intertec label is a bit of a red herring and the drives 
are actually Tandon TM100-1 full height units. I’ve got the manual from a Rat 
Shack related site.

Thanks for making me look again :) 

-- 
adrian/witchy
Owner of Binary Dinosaurs, the UK's biggest private home computer collection?
t: @binarydinosaursf: facebook.com/binarydinosaurs
w: www.binarydinosaurs.co.uk

Re: ISO Intertec 5.25" floppy drive jumper settings

[Adrian Graham via cctalk]

> On 3 Dec 2018, at 00:22, Fred Cisin via cctalk  wrote:
> 
>>> When they went to 400K 40 cylinder MFM DSDD / double sided, double density, 
>>> still 48 tpi (like the PC-DOS 360K), they chose to call that "QD" / "QUAD 
>>> DENSITY"!! ?!??  (equating "density" with capacity) WHOA! Everybody else 
>>> called THAT DSDD "Double Sided Double Density", and used "QD" / "Quad 
>>> Density" to refer to 80 cylinder Double density 96tpi!
> On Mon, 3 Dec 2018, Adrian Graham via cctalk wrote:
>> So I’ve been reading :) I’m sure they weren’t doing it deliberately, hahaha.
> 
> It's hard to say.  At NCC, at the Intertec booth, they could not understand 
> WHY anybody would want to transfer files between disk formats, other than to 
> PIRATE their "proprietary software"!  They even threatened to sue me if I 
> included it in XenoCopy!
> So, they were not heavy into interoperability with other brands.

Was any manufacturer? I does seem to me that everyone deliberately made their 
CP/M format different despite using the same or similar chipsets. I was 
surprised to read in the docs for my Osborne Executive that it COULD read a 
couple of other formats.

> That was the first time that I added a format to XenoCopy while in a hotel 
> room.  (Televideo was the second!).  NCC was great.  In addition to those two 
> formats, in exchange for buying him lunch, John Draper told me everything 
> that I needed to know to add UCSD P-System formats - (I did NOT exercise with 
> him.) Intertec did not keep their promise - I could have used the free ink.

What machine were you using for hotel room coding?

> One more caveat!  Radio Shack repurposed pin 32 (SIDE SELECT) to use as their 
> fourth drive select, and did their drive select with their cable, rather than 
> the jumpers.  So did IBM, although they jumpered both drives as second drive, 
> rather than ALL jumpered as RS had done.  IBM also used them, as well as the 
> TM100-2 (DS), so there are a LOT of sources for the manuals.

This pair are jumpered as I’d expect, DS0 and 1 with a terminator block. The 
manual says they’ll work with multi-hole floppies so I’ll strip them down later 
and give them a good clean.

-- 
adrian/witchy
Owner of Binary Dinosaurs, the UK's biggest private home computer collection?
t: @binarydinosaursf: facebook.com/binarydinosaurs
w: www.binarydinosaurs.co.uk

Re: CDC floppy disks on Ebay.

[Adrian Graham via cctalk]

> On 9 Dec 2018, at 21:40, Mattis Lind via cctalk  wrote:
> 
> Don't know if this worth saving. https://www.ebay.com/itm/283294561797
> 
> 8 inch CDC disks from 1982. Maybe something interesting?


It might be just me, but those look like they’ve got great big holes cut in 
them?

-- 
adrian/witchy
Owner of Binary Dinosaurs, the UK's biggest private home computer collection?
t: @binarydinosaursf: facebook.com/binarydinosaurs
w: www.binarydinosaurs.co.uk

Re: CDC floppy disks on Ebay.

[Adrian Graham via cctalk]

> On 9 Dec 2018, at 22:40, Brent Hilpert via cctalk  
> wrote:
> 
> On 2018-Dec-09, at 2:06 PM, Adrian Graham via cctalk wrote:
>>> On 9 Dec 2018, at 21:40, Mattis Lind via cctalk  
>>> wrote:
>>> 
>>> Don't know if this worth saving. https://www.ebay.com/itm/283294561797
>>> 
>>> 8 inch CDC disks from 1982. Maybe something interesting?
>> 
>> It might be just me, but those look like they’ve got great big holes cut in 
>> them?
>> 
> 
> If you're thinking of the blue 'slashes' near the horizontal middle of the 
> disks that look like the back of the pouch showing through a hole cut in the 
> disk, I think those are  actually tabs on the back of the pouch extending up 
> in front of the next disk back, kind of like file folder tabs.
> Don't think I've seen pouches with that before but probably intended to make 
> it easy to grab a disk by the pouch when they're all down in the box.
> Look at the magnified view of the 3rd pic.


Ah yes, that makes much more sense. I can see it now.

-- 
adrian/witchy
Owner of Binary Dinosaurs, the UK's biggest private home computer collection?
t: @binarydinosaursf: facebook.com/binarydinosaurs
w: www.binarydinosaurs.co.uk

Re: PDP-11 Memory

[Adrian Graham via cctalk]

> On 11 Jan 2019, at 23:59, Ethan Dicks via cctalk  
> wrote:
> 
> On Fri, Jan 11, 2019 at 4:39 PM Pete Turnbull via cctalk
>  wrote:
>>> Mine are all BA23.  Wasn't the BA123 for the MicroVAX?
>> 
>> No, it was introduced for the microPDP-11 series, and only later used
>> for MicroVAX and MicroVAX-II.  There are many microPDP-11/83 machines in
>> BA123 cabinets, it was a very popular option because of the space for
>> storage devices and the extra backplane slots.
> 
> Hmm... I did not know they put the 11/83 in a BA123.  It makes sense
> since, as you say, there's room for storage devices and plenty of
> slots.


It’s going back severalteen years now but I’m pretty sure I built a Micro 73 
into a BA123, it’s a CD22 backplane after all. I still have all the cards AND 
the BA123 but I’m supposed to be turning it back into the MVII it was 
originally, back in 1986 when it was called FRUIT. 

-- 
adrian/witchy
Owner of Binary Dinosaurs, the UK's biggest private home computer collection?
t: @binarydinosaursf: facebook.com/binarydinosaurs
w: www.binarydinosaurs.co.uk

TRS80 Model 3/4 help in Fremont OH

[Adrian Graham via cctalk]

Hi folks,

I've been chatting to someone who has a TRS80 Model 4 that's giving him a
horizontal sync issue, is there anyone around the Fremont area who could
give him a hand with it?

Cheers

-- 
adrian/witchy
Owner of Binary Dinosaurs, the UK's biggest private home computer
collection?
t: @binarydinosaursf: facebook.com/binarydinosaurs
w: www.binarydinosaurs.co.uk

tape transport drive belts

[Adrian Graham via cctalk]

Evening folks,

I’m bringing a Sharp MZ80B back to life and have so far fixed a horizontal 
collapse problem on the video board meaning I can see what it’s prompting for 
at boot. I remember when I first got this machine back in 2003-ish I dismantled 
it and discovered some of the tape transport had melted and gummed up the 
automatic head mechanism.

Fast forward* 15 years and I have the transport in bits again on the bench and 
I can see that one belt has melted and another is on the way to collapse. Did 
we ever find a reasonable source of replacement belts? I know a couple of 
collector friends with 3D printers have printed replacements but this is new 
tech and I need old tech :)

Cheers!

*sorry, pun intended

-- 
adrian/witchy
Owner of Binary Dinosaurs, the UK's biggest private home computer collection?
t: @binarydinosaursf: facebook.com/binarydinosaurs
w: www.binarydinosaurs.co.uk

Re: Ultimate FDC? (Was: IBM 6360 - Filesystem(ish) info?

[Adrian Graham via cctalk]

Hello folks,

I'm coming into this a bit late but a bloke called David Given is working
on such a floppy controller right now, it's called Fluxengine and is based
around a Cypress microcontroller that connects directly to a floppy drive
and is driven by USB. Early days as yet in that it supports IBM formats
plus Acorn BBC DFS/ADFS but since all the decoding is done in software
pretty much any format can be added and David is looking for examples of eg
C1541 floppies from the C64 as well as others.

https://github.com/davidgiven/fluxengine

-- 
adrian/witchy
Owner of Binary Dinosaurs, the UK's biggest private home computer
collection?
t: @binarydinosaursf: facebook.com/binarydinosaurs
w: www.binarydinosaurs.co.uk


On Tue, 19 Feb 2019 at 23:40, William Sudbrink via cctalk <
cctalk@classiccmp.org> wrote:

> A design that can manage Ohio Scientific as well would be nice.
>
>
> ---
> This email has been checked for viruses by Avast antivirus software.
> https://www.avast.com/antivirus
>
>

DECserver 700 PSU fix, H7881-AA

[Adrian Graham via cctalk]

Hi folks,

My trusty DECserver has bitten the dust in a silent and non-violent way
with the fuse still intact so has anyone got tips on troubleshooting? I
know it's the PSU because I 'borrowed' another PSU from work and the unit
is running again. It's an ASTEC unit under the hood, and in my experience
of fixing the older types like the AC8151 (Memotech, TRS80 II/III, Osborne
etc) the chief culprits on an utterly dead PSU are the input caps and/or
the small 220uF or 330uF startup cap in the feedback circuit.

I haven't checked bitsavers etc for a schematic yet, does such a thing
exist? Helpfully the ASTEC board doesn't have a model number on it.

Cheers

-- 
adrian/witchy
Owner of Binary Dinosaurs, the UK's biggest private home computer
collection?
t: @binarydinosaursf: facebook.com/binarydinosaurs
w: www.binarydinosaurs.co.uk

Re: Mystery old computer & terminals on eBay UK

[Adrian Graham via cctalk]

I thought that was a variant of the BCL Mollie, aka Molecular 18 but google
disagrees with me. TnMOC have 2 of them so I'll ask the volunteers.

-- 
adrian/witchy
Owner of Binary Dinosaurs, the UK's biggest private home computer
collection?
t: @binarydinosaursf: facebook.com/binarydinosaurs
w: www.binarydinosaurs.co.uk


On Wed, 27 Feb 2019 at 11:13, Liam Proven via cctalk 
wrote:

> I don't recognise this, but I'm no expert.
>
> https://www.ebay.co.uk/itm/113665872765
>
> --
> Liam Proven - Profile: https://about.me/liamproven
> Email: lpro...@cix.co.uk - Google Mail/Hangouts/Plus: lpro...@gmail.com
> Twitter/Facebook/Flickr: lproven - Skype/LinkedIn: liamproven
> UK: +44 7939-087884 - ČR (+ WhatsApp/Telegram/Signal): +420 702 829 053
>

Re: Mystery old computer & terminals on eBay UK

[Adrian Graham via cctalk]

Go me :)  I've not laid eyes on one of those since I hefted them out of the
main computer suite in TnMOC's H-Block back in the noughties so we could
clean the room before the arrival of the ICL 2966. I hope they're still
around.

-- 
adrian/witchy
Owner of Binary Dinosaurs, the UK's biggest private home computer
collection?
t: @binarydinosaursf: facebook.com/binarydinosaurs
w: www.binarydinosaurs.co.uk


On Wed, 27 Feb 2019 at 11:41, Liam Proven via cctalk 
wrote:

> On Wed, 27 Feb 2019 at 12:24, Jonathan Katz  wrote:
> >
> > Some google shows BCL=Business Computers Limited (potentially)
>
> Foolishly I didn't read the comments first.
>
> It's one of these:
>
> http://www.ps8computing.co.uk/bcl.html
>
> --
> Liam Proven - Profile: https://about.me/liamproven
> Email: lpro...@cix.co.uk - Google Mail/Hangouts/Plus: lpro...@gmail.com
> Twitter/Facebook/Flickr: lproven - Skype/LinkedIn: liamproven
> UK: +44 7939-087884 - ČR (+ WhatsApp/Telegram/Signal): +420 702 829 053
>

Re: DECserver 700 PSU fix, H7881-AA

[Adrian Graham via cctalk]

Hi folks,

Thanks for the links, I should’ve said I work for a DEC/HPE reseller so I can 
get replacements through work but I thought there might be some folk here 
who’ve fixed one before and might have some tips.

Cheers again

Adrian


> On 27 Feb 2019, at 18:06, Electronics Plus via cctalk  
> wrote:
> 
> https://shop.mitservices.com/product/digital-dec-server-700-psu-h7881-aa/
> in stock in the UK.
> 
> -Original Message-
> From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Gregory
> Beat via cctalk
> Sent: Monday, February 25, 2019 12:48 PM
> To: binarydinosa...@gmail.com; cctalk@classiccmp.org
> Subject: Re: DECserver 700 PSU fix, H7881-AA
> 
> Adrian -
> 
> ASTEC is now owned by Emerson Power (UK address below).
> Emerson Power Catalog (find the 57 watt models):
> https://www.mouser.com/catalog/supplier/library/pdf/Emersonpower_catalog.pdf
> 
> PowerClinic in Dallas/Fort Worth area 
> services a large number of Switch-Mode power supplies.
> http://portal.powerclinicinc.com/web/services
> Power Clinic Inc.
> 3732 Arapaho Rd
> Addison, TX 75001
> USA
> ==
> H7881-AA (Refurbished), $177.00 USD
> https://www.tamayatech.com/parts.php?g=H7881AA
> 
> H7881-AA Power Supply, 57 watt , $450.00 USD
> https://www.ipsystemsinc.com/shopping/pgm-more_information.php?id=630
> 
> ASTEC - Europe (UK)
> Waterfront Business Park
> Merry Hill, Dudley
> West Midlands, DY5 1LX
> United Kingdom
> Telephone: +44 (0) 1384 842 211 
> Facsimile: +44 (0) 1384 843 355
> ==
> From: Adrian Graham
> To: "General Discussion: On-Topic and Off-Topic Posts"
> Subject: DECserver 700 PSU fix, H7881-AA
> 
> Hi folks,
> 
> My trusty DECserver has bitten the dust in a silent and non-violent way
> with the fuse still intact so has anyone got tips on troubleshooting? I
> know it's the PSU because I 'borrowed' another PSU from work and the unit
> is running again. It's an ASTEC unit under the hood, and in my experience
> of fixing the older types like the AC8151 (Memotech, TRS80 II/III, Osborne
> etc) the chief culprits on an utterly dead PSU are the input caps and/or
> the small 220uF or 330uF startup cap in the feedback circuit.
> 
> I haven't checked bitsavers etc for a schematic yet, does such a thing
> exist? 
> Hopefully the ASTEC board has a model number on it.
> 
> Cheers
> -- 
> adrian/witchy
> Owner of Binary Dinosaurs, the UK's biggest private home computer
> collection?
> t: @binarydinosaurs
> f: facebook.com/binarydinosaurs
> w: www.binarydinosaurs.co.uk
> 
> 
> ---
> This email has been checked for viruses by Avast antivirus software.
> https://www.avast.com/antivirus
> 

-- 
adrian/witchy
Owner of Binary Dinosaurs, the UK's biggest private home computer collection?
t: @binarydinosaursf: facebook.com/binarydinosaurs
w: www.binarydinosaurs.co.uk

Re: Pleas ID this IBM system....

[Adrian Graham via cctalk]

> On 6 Apr 2019, at 18:58, Adrian Stoness via cctalk  
> wrote:
> 
> is it me or is it sitting on a riased floor

I thought that while at the same time marvelling what great condition it all 
seems to be in, like they just turned everything off, locked the door and left 
for 40 years.

-- 
adrian/witchy
Owner of Binary Dinosaurs, the UK's biggest private home computer collection?
t: @binarydinosaursf: facebook.com/binarydinosaurs
w: www.binarydinosaurs.co.uk

Re: Telex 20 Meg 10 platter very heavy monster drive needed drop line off list..r

[Adrian Graham via cctalk]

> On 22 Apr 2019, at 20:05, geneb via cctalk  wrote:
> 
> On Mon, 22 Apr 2019, ED SHARPE via cctalk wrote:
> 
>> Al,  the  drive   you mention at  its  largest   was  7.5 meg  and  6  
>> platters... notthe   one  ... an  interesting   drive  but  not  the  
>> dive   we  need  alas...  Ed#
>> 
> With all the extra whitespace, all my brain hears when I read that is William 
> Shatner.

You owe me a beer for that comment :D 

-- 
adrian/witchy
Owner of Binary Dinosaurs, the UK's biggest private home computer collection?
t: @binarydinosaursf: facebook.com/binarydinosaurs
w: www.binarydinosaurs.co.uk

Re: VCF Southeast Photos

[Adrian Graham via cctalk]

> On 1 May 2019, at 21:10, Jason T via cctalk  wrote:
> 
> Last weekend I made an unannounced visit out to Roswell, GA to visit
> our brothers-and-sisters-in-hoarding at the Vintage Computer Festival
> Southeast.  They were hosted by the new location of the Computer
> Museum of America, not yet open to the public.  The show was a solid
> representation of the hobby, with a wide range of micros, minis and
> workstations as well as a few calculators and computing ephemera.  On
> the museum side, I've never seen so many Crays in once place - and
> they're not even done yet!
> 
> Here is my photo set:  https://photos.app.goo.gl/aiKGadREX511xeUt5
> (contains computers, computer collectors and one giant rabbit)
> 
> Big thanks to Earl and the gang for putting on another great VCF and
> showing me that southern hospitality.


Oh wow, a Thinking Machines CM-3 running?! That plus the PDP-12/PDP-15, aw man. 
Excellent set of pics Jason, cheers!

-- 
adrian/witchy
Owner of Binary Dinosaurs, the UK's biggest private home computer collection?
t: @binarydinosaursf: facebook.com/binarydinosaurs
w: www.binarydinosaurs.co.uk

Re: VCF Southeast Photos

[Adrian Graham via cctalk]

> On 1 May 2019, at 22:42, alan--- via cctalk  wrote:
> 
> 
> It's a CM-2.  The problem with most CM-2s - aside not working in 2019 - is 
> most were never fully populated with card cages in all 8 hyper-cubes.  That 
> particular machine only has card cages in 2 of the hyper-cubes.  The other 6 
> are empty.  I'm not sure a machine with max 64K processors was ever actually 
> sold to a real customer.

Oh.

> The CM-2 in the photo has faux LED panels installed with LEDs spacing that 
> exactly matches the real CPU card stacks.  Each of the 4096 LEDs are 
> individually PWM'd and addressable.  The blinky pattern is generated by a 
> ESP32 which can also be WiFi and BT controlled.  Only pulls about 100 Watts 
> with that pattern running.


I suppose in this day and age that’s all I need to see since the machine itself 
would be, as William says, fantastically useless. I was definitely swooned by 
the marketing shots back in the day though.

-- 
adrian/witchy
Owner of Binary Dinosaurs, the UK's biggest private home computer collection?
t: @binarydinosaursf: facebook.com/binarydinosaurs
w: www.binarydinosaurs.co.uk

Re: Procedure to convert a vax into a stand alone workstation in a LAN

[Adrian Graham via cctalk]

> On 2 May 2019, at 23:16, Carlos E Murillo-Sanchez via cctalk 
>  wrote:
> 
> Hello;
> 
> In my quest to try to see what the problem is with my vs/60, I want to 
> convert it into a networked stand-alone machine, i.e. not use clustering at 
> all.  What is the easiest way to do this? I still want it to do DECnet and 
> TCPIP.
> 
> Carlos.
> 


The easiest way is to turn clustering off, so if the machine’s running press 
the HALT button then from the Dead Sergeant prompt (>>>) do this:

>>> B/1 (or B/R5:1)
SYSBOOT> SET VAXCLUSTER 0
SYSBOOT> C

This will boot as a single node and let you log in assuming your SYSUAF.DAT 
isn’t on a clustered drive. If it is add this command after SET VAXCLUSTER 0:

SYSBOOT> SET UAFALT 1

This bypasses the main system authorisation file and lets you log in as SYSTEM 
with no password. Usually. The caveat emptor here is if the previous owners 
also used a SYSUAF_ALT file in which case it gets a little more complex.

-- 
adrian/witchy
Owner of Binary Dinosaurs, the UK's biggest private home computer collection?
t: @binarydinosaursf: facebook.com/binarydinosaurs
w: www.binarydinosaurs.co.uk

Re: Hayes Transet Manual and Software

[Adrian Graham via cctalk]

> On 5 May 2019, at 03:57, Jason T via cctalk  wrote:
> 
> On Sun, Dec 16, 2018, 23:43 Jason T  wrote:
> 
>> One of my few remaining Holy Grail items, I got a Hayes Transet 1000
>> this week.  My three-part Hayes stack is now complete.
>> 
> 
> Another Transet just sold on eBay:
> 
> https://www.ebay.com/itm/382925076475
> 
> And this one has the 5.25" PC software disk that mine did not.  If anyone
> here won the item, please make an effort to image the disk.
> 
> Interesting that the still rare but more common than the Transet
> Chronograph, from the same seller, got over $100 more.
>> 

I read that as ‘trainset’ and got derailed temporarily.

-- 
adrian/witchy
Owner of Binary Dinosaurs, the UK's biggest private home computer collection?
t: @binarydinosaursf: facebook.com/binarydinosaurs
w: www.binarydinosaurs.co.uk

Re: Apple ][+ Keyboard

[Adrian Graham via cctalk]

Hi Mark,

I have a contact in Belgium who has made some PS2 adapter PCBs if you'd
like me to put you in contact, he was advertising them on Facebook a week
or so ago.

-- 
adrian/witchy
Owner of Binary Dinosaurs, the UK's biggest private home computer
collection?
t: @binarydinosaursf: facebook.com/binarydinosaurs
w: www.binarydinosaurs.co.uk


On Thu, 23 May 2019 at 13:22, John Many Jars via cctalk <
cctalk@classiccmp.org> wrote:

> Hi Brian,
>
> That's an interesting thread.  It probably is the encoder chip as hitting
> Ctrl-Reset works.  Unfortunately Briel Computers doesn't seem to exist
> anymore. ):
>
> This seems like a temporary solution.  I need to collect the stuff to build
> one:
>
> https://knzl.at/ps2-keyboard-for-apple-ii/
>
> Thanks!
>
> Mark
>
> On Wed, 22 May 2019 at 17:00, Brian Marstella  wrote:
>
> > Just ran across this a few days ago on different search...
> >
> > https://groups.google.com/forum/#!topic/comp.sys.apple2/kJ4SosdZTb4
> >
> > May have some helpful info.
> >
> > On Wed, May 22, 2019 at 11:56 AM John Many Jars via cctalk <
> > cctalk@classiccmp.org> wrote:
> >
> >> I feel like I'm falling down a rabbit hole with this old ][ europlus
> I've
> >> had for years.
> >>
> >> The smoke came out of the power supply, so I replaced it with one from
> >> ReactiveMicro.  Now it boots, and was working okay, until this morning.
> >> Now, no keyboard  if you hit ctrl-reset.  All other keys are
> >> ignored.
> >>
> >> Anyone have any ideas? (:
> >>
> >> Thanks,
> >>
> >> John (aka Mark)
> >>
> >
>
> --
> Yoyodyne Propulsion Systems:  "The Future Begins Tomorrow"
> Visit us at: http://www.yoyodyne-propulsion.net
>
> 
> "When a true genius appears in the world, you may know him by this sign,
> that the dunces are all in confederacy against him." -- Jonathan Swift
>

Re: Abandoned FACOM system in Italy?

[Adrian Graham via cctalk]

> On 27 May 2019, at 20:18, Jason T via cctalk  wrote:
> 
> On Mon, May 27, 2019 at 7:32 AM Evan Linwood via cctalk
>  wrote:
>> There doesn't seem to be mention of any recovery effort in the comments 
>> (that I could see).
>> The most interesting section is from 14:14:
>> https://www.youtube.com/watch?v=rrx1tK5xcAk
> 
> Oof, 5:30 is a tragic sight for any IBM terminal fan.


Or just any fan of old kit, my heart absolutely sank watching that.

-- 
adrian/witchy
Owner of Binary Dinosaurs, the UK's biggest private home computer collection?
t: @binarydinosaursf: facebook.com/binarydinosaurs
w: www.binarydinosaurs.co.uk

Re: COMX-35

[Adrian Graham via cctalk]

> On 3 Jun 2019, at 17:59, Ethan Dicks via cctalk  wrote:
> 
> On Sat, Jun 1, 2019 at 12:19 PM James Wilkinson via cctalk
>  wrote:
>> Anyone happen to have one for sale/trade?
> 
> I do not, but it sounds like a fun machine.  I have lots of 1802 stuff
> but not that one.
> 
> -ethan


I know of some for sale in The Netherlands, they’re NOS and don’t have a power 
supply, last price I saw them at was €350. This is why I haven’t bought one :) 

-- 
adrian/witchy
Owner of Binary Dinosaurs, the UK's biggest private home computer collection?
t: @binarydinosaursf: facebook.com/binarydinosaurs
w: www.binarydinosaurs.co.uk

Re: RSTS collection in the UK

[Adrian Graham via cctalk]

> On 25 Jun 2019, at 17:50, Pete Turnbull via cctalk  
> wrote:
> 
> Hi, Al.
> 
> This sounds slightly familiar - Jay contacted me a year or two ago about a 
> similar lot but the donor never got back to me.
> 
> Anyway, I would be happy to collect these on behalf of Jim Austin, for the 
> Computer Sheds:  http://www.computermuseum.org.uk/ 
> We'd be particularly interested in the 
> RSTS stuff, as we have very little of that.
> 

I too have a load of RSTS docs I’ve been trying to move on for a few years. 
Antonio was going to take them but ended up in the US so they’re still all in 
my hallway, you’re welcome to those too!

Cheers

-- 
adrian/witchy
Owner of Binary Dinosaurs, the UK's biggest private home computer collection?
t: @binarydinosaursf: facebook.com/binarydinosaurs
w: www.binarydinosaurs.co.uk


> Please pass on my contact details.
> 
> On 25/06/2019 17:20, Al Kossow via cctalk wrote:
>> We received this offer, it probably makes more sense for someone in the UK 
>> to get the lot.
>> Is there someone at a collecting institution that would like to take this 
>> on? Email me and
>> I can forward your contact information to them.
>> "I have a few disk packs available if you need them. (Please note I am in 
>> the UK). I also have a range of PDP-11
>> interface boards, a mix of dual, quad and Unibus. Is there anything in 
>> particular that you need? Finally I have a mass
>> of RSTS related documentation, such as one copy of every edition of the US 
>> publication RSTS Porfessional magazine. Plus
>> copies of RSTS and RT-11 operating system manuals, from RSTS Version 4a 
>> (1974) through to Version 10.1 (mid 1990s)."
> 
> 
> -- 
> Pete
> Pete Turnbull

RSTS/RSX manuals available in the UK

[Adrian Graham via cctalk]

Hi folks,

I’ve held onto this collection of manuals for the last 3 years and now they 
really need to go because I’m having to move house in the next 2-3 months, my 
landlady is selling up. I thought it was too good to be true being in this 
house for 7.5 years!

The RSTS manuals are V10 (1990) and there's 3 RSX-11M V4 as well as RSX DECNET. 
I don’t have the time to scan them myself otherwise I would’ve done ages ago.

I’m heading past Jim Austin’s place in a couple of weeks’ time so if nobody 
else is interested I can drop them off there if he’s up for it.

Cheers,

-- 
adrian/witchy
Owner of Binary Dinosaurs, the UK's biggest private home computer collection?
t: @binarydinosaursf: facebook.com/binarydinosaurs
w: www.binarydinosaurs.co.uk

FW: More 8085a oddities

[Adrian Graham via cctalk]

Hi folks,

I didn't see the message at the bottom of this one arrive since I think I
sent it JUST as the list software was being changed over.

Gah, having just looked again I realise I've sent it from not the address
I've subbed with. PEBCAK there :)

Since then I discovered the -5V rail for the 4116s had dropped to -4.2V
which was out of spec for both types of RAM on this box so on Chuck's
suggestion I swapped the 560ohm resistor/zener combo that was powering this
rail for a 79L05 regulator and the DRAMs now have all 3 voltages steady.

No change in behaviour though. I'm baffled as to why the upper address bus
doesn't blip once RESET goes high. HOLD is permanently pulled low so it's
not that.

Any suggestions?

Cheers!

-- 
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?

-- Forwarded Message
From: Adrian Graham 
Date: Sun, 26 Feb 2017 23:34:50 +
To: "Discussion: On-Topic and Off-Topic Posts" 
Conversation: More  8085a oddities
Subject: More  8085a oddities

Hi folks,

After a few days break I came back to my 8085a-powered phone system this
weekend and it's decided to go on strike. By that I mean the processor locks
up after only a few cycles so doesn't get as far as attempting to read
anything, when it freezes the S0/S1/WR status lines are all high which
shouldn't be possible since S0/S1 high should be 'Fetch' according to the
manual, not WRITE.

Vcc, RESET and clock are good and I can't see any other external signal
which might hold the CPU. The PSU is good and putting out +5/+12/-12 as it
should. CPU checks out in another 8085 system I forgot I had.

Interestingly my analyser shows the upper half of the address bus doesn't
change while the lower half manages a single transition, as does the ALE
signal. From the CPU both halves of the address bus go directly to a 74LS373
each which both check out OK on a breadboard circuit I made up earlier.

ROMs are all OK and the lines themselves back to the LS373 and CPU check out
with little resistance.

I'm stumped and can't help but think this is something stupid which I'm
overlooking. Maybe more sleep will help.

Cheers!

--  
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?

-- End of Forwarded Message

Re: FTGH (you come get): VAXstation 100 terminals

[Adrian Graham via cctalk]

On 06/03/2017 16:43, "Ethan Dicks via cctalk"  wrote:

> On Mon, Mar 6, 2017 at 2:56 AM, Cameron Kaiser via cctalk
>  wrote:
>> I picked these up as part of an estate liquidation, but I don't have a
>> Unibus setup to run them off, and they are large and taking up space.
> 
> They sound like fun (I never got to play with stuff like that when it
> was new - back in the mid-80s we were 100% dumb terminals, no
> workstations).  Sadly, I'm far too far away to help rescue.

Ditto, ditto and ditto. Wrong side of the pond :/

In fact, up until this morning I had no idea such a beast existed!

-- 
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?

Re: Test

[Adrian Graham via cctalk]

Test again, None of my posts seem to be getting through...


On 28/02/2017 00:35, "Jay West"  wrote:

> Test received ;)
> 
> -Original Message-
> From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Adrian
> Graham
> Sent: Monday, February 27, 2017 6:34 PM
> To: Discussion: On-Topic and Off-Topic Posts 
> Subject: Test
> 
> Ezwind?
> --
> Adrian/Witchy
> Binary Dinosaurs creator/curator
> Www.binarydinosaurs.co.uk - the UK's biggest private home computer
> collection?
> 
> 
> 

Re: Test

[Adrian Graham via cctalk]

On 07/03/2017 07:12, "Tor Arntsen"  wrote:

> On 7 March 2017 at 01:18, Adrian Graham via cctalk
>  wrote:
>> Test again, None of my posts seem to be getting through...
> 
> Saw it. And also what you sent a day ago(?), about using the 79L05

Thanks for the replies! It's odd then that I don't see my own messages on
the list any more then, and the one I sent at changeover time hasn't hit the
archive whereas other folks' messages have.

-- 
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?

Re: 10x life size sculpture of a ZX Spectrum PCB

[Adrian Graham via cctalk]

On 09/03/2017 13:20, "Liam Proven via cctalk"  wrote:

> Since, to my pleased surprise, this has been a runaway hit on
> Facebook, I thought I'd reshare it here.
> 
> My friend Roger took a picture of this sculpture at the Jerwood
> Gallery in Hastings on the south coast of England:
> 
> https://www.flickr.com/photos/25143643@N07/32505083723
> 
> It's a piece called "A Mystery to Myself" by Keith Tyson.
> 
> http://keithtyson.com/work/a-mystery-to-myself/
> 
> There are more pictures from this showing at a different galley:
> 
> http://www.davidrisleygallery.com/exhibitions/keith-tyson2

Nice attention to detail there but who's going to tell him the wiring on his
modulator looks odd :D

-- 
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?

Re: help needed installing USB to Serial Cable for ADTPro

[Adrian Graham via cctalk]

On 11/03/2017 05:39, "Joe Giliberti via cctalk" 
wrote:

> Greetings!
> I am trying to connect my IIc to my laptop through ADTPro and am
> having trouble getting the FT232R adapter I bought from Retro Floppy.
> The host computer is an HP Elitebook running Windows 7 Pro 64-bit.
> When I first plugged in the cable, Windows tried and failed to find
> the device drivers. I downloaded the drivers from the manufacturer of
> the chip and and ran it. It told me installation was successful and
> device manager recognized that there was a USB serial port, but
> reported an Unknown Device and a Base System Device that didn't have
> drivers installed. I tried to use ADTPro but it didn't see a serial
> port.
> 
> Has anyone run into this issue before?

Yes, several times though like Raymond says you may be stymied straight away
if your adapter is using a fake FTDI chip. Neither of my adapters work with
ADTPro largely because of the signals I think it's expecting to get with
regard to hardware handshaking. Also they're using CH340/1 chips which are
the Chinese FTDI clones.

Recently I tried setting up a Raspberry Pi using a genuine FTDI USB breakout
adapter that gives all handshake signals but couldn't get that to work
either and resorted back to my old faithful XP desktop with real 16550 UART
which works every time.

My next idea was to get a BusPirate to see exactly what signals were in use
on the real serial port but at the time BusPirates weren't available. Now I
see they are again so I might have another look.

-- 
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?

Re: 10x life size sculpture of a ZX Spectrum PCB

[Adrian Graham via cctalk]

On 11/03/2017 08:57, "Peter Corlett via cctalk" 
wrote:

> On Fri, Mar 10, 2017 at 05:14:55PM +, Adrian Graham via cctalk wrote:
>> On 09/03/2017 13:20, "Liam Proven via cctalk"  wrote:
> [...]
>>> My friend Roger took a picture of this sculpture at the Jerwood Gallery in
>>> Hastings on the south coast of England:
>>> https://www.flickr.com/photos/25143643@N07/32505083723
> 
> A Model 3, by far the most photogenic of all the boards because the design has
> the fewest bugs and isn't covered with bodge wires. Whether the artist knows
> this is debatable; only collectors tend to care about this stuff and the Model
> 3 was by far the most common.
> 
> [...]
>> Nice attention to detail there but who's going to tell him the wiring on his
>> modulator looks odd :D
> 
> It is no doubt faithful to the usual half-arsed assembly job that comes free
> with every Sinclair machine :)

His has the regular RF connection and I suspect the red wire is a facsimile
of the usual composite mod which is to take the video signal straight out of
the RF port after disconnecting the modulator internals...

-- 
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?

Re: help needed installing USB to Serial Cable for ADTPro

[Adrian Graham via cctalk]

On 11/03/2017 21:52, "Joe Giliberti via cctalk" 
wrote:

> The cable is branded "Ugreen." I've had difficulties with USB to RS232
> adapters in the past, which is why I bought it from the ADTPro
> website. I figured that it would be more likely to work straight away.

I've had difficulties with everything I've used from ugreen, the latest
being an HDMI-DVA adapter which just didn't work 100%. Trouble is with some
of these ebay buys you don't know who made it until it lands on your mat.
 
> On a venture to the grocery store today, I stopped in at a Radioshack
> which was having a liquidation sale. I bought their "Gigaware" USB to
> serial cable for a decent discount at $20. As I understand it, this
> one uses a Prolific chipset which can occasionally be troublesome..
> Thankfully, there appear to be drivers for it specifically for Windows
> 7.

Prolific! That's the chipset name I was trying to remember earlier. Seems
that most ADTPro folks have more success with that one than the others.

-- 
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?

HP Portable Plus 110 available in Ireland

[Adrian Graham via cctalk]

Hi folks,

Got this email from Shane in Ireland who'd like to trade a Portable Plus for
anything videogaming wise, original message below so please reply to Shane
if you're interested:

--
> Message from Shane Hurley (shane...@hotmail.com) on February 27th, 2017 at
> 10:37PM (GMT).
> 
> Hey there!
> 
> I currently have a Hewlett Packard Portable Plus but NO POWER SUPPLY! I
> actually have the original leather case for it too, for whatever that's worth.
> 
> Here's the ML & SL:
> 
> Model Number 45711F
> 
> Serial Number 2629A15219
> 
> I know these things can be of big value to some folk but not me and I'd love
> for it to go somewhere where it could be used or loved.
> 
> If this is something you'd like, I'd be happy to trade for anything video game
> related. I have a small retro games stall open on weekends here in Ireland and
> am always on the lookout for ways to make it work. I'm sure you understand the
> way it can be.
> 
---

Cheers,

-- 
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?

Re: help needed installing USB to Serial Cable for ADTPro

[Adrian Graham via cctalk]

On 12/03/2017 01:52, "Joe Giliberti via cctalk" 
wrote:

> Not great news :(
> The computer recognized the serial port on COM5 and ADTPro says that
> it is connected. I am using the null modem cable from RetroFloppy for
> the //c and the Radioshack cable with the Prolific chipset (I switched
> over to this one because I thought this problem was caused by the
> other cable.) I set the working directory in ADT where the DSK files
> are and set the baud rate in Windows, ADT on the PC and ADT on the //c
> all to 19200. When I boot up the //c, I select (R)ecieve, punch in the
> filename, hit enter and...Host Timeout.
> Any idea what might not be working now?
> 
> I really appreciate everyone's help
>

You can check if the PC is talking to the //c by doing a bare metal
speediboot - this will check the comms are working:

http://adtpro.sourceforge.net/bootstrap.html

Can you do a lookback test on the USB adapter by looping pins 2&3 then using
PuTTY to talk to itself?

-- 
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?

Re: server up

[Adrian Graham via cctalk]

On 12/03/2017 07:10, "Jay West via cctalk"  wrote:

> The server seems to be alive at the new IP, mail flowing, websites up..
> 
>  
> 
> Still checking a few things, but appears complete.

Nice one Jay!

-- 
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?

Re: help needed installing USB to Serial Cable for ADTPro

[Adrian Graham via cctalk]

On 12/03/2017 20:57, "Joe Giliberti via cctalk" 
wrote:

> The bootstrapping option is grayed out in ADT so I can't do that. I
> don't have access to my usual tools for the next few days, so I can't
> loop the pins
> 

I've replied on FB but for completeness and historical recording I'll put it
here too. Granted the PC currently in use is a 32bit XP machine so I could
make sure everything was working on a real 16550 UART before going over to
the USB adapter but I'll try a win 7 64bit machine when I get the chance.

My adapter is a clone one with the CH340 chipset used and abused on arduino
clones so I already had the driver package, it was discovered as COM4.

Fire up ADTPro via the .bat file, go to serial setup to make sure COM4 is
selected along with '//c with imagewriter cable' then plug in the //c and
boot to the ] prompt followed by:

IN#2
14B

On the PC go to 'bootstrapping -> ProDOS -> speediboot' and hit OK...up she
comes.

I've just seen a message from David Schmidt, if anyone knows why yours
doesn't work he will given that he wrote ADTPro in the first place :)

Cheers


> On Sun, Mar 12, 2017 at 5:28 AM, Adrian Graham via cctalk
>  wrote:

>> On 12/03/2017 01:52, "Joe Giliberti via cctalk" 
>> wrote:
>> 
>>> Not great news :(
>>> The computer recognized the serial port on COM5 and ADTPro says that
>>> it is connected. I am using the null modem cable from RetroFloppy for
>>> the //c and the Radioshack cable with the Prolific chipset (I switched
>>> over to this one because I thought this problem was caused by the
>>> other cable.) I set the working directory in ADT where the DSK files
>>> are and set the baud rate in Windows, ADT on the PC and ADT on the //c
>>> all to 19200. When I boot up the //c, I select (R)ecieve, punch in the
>>> filename, hit enter and...Host Timeout.
>>> Any idea what might not be working now?
>>> 
>>> I really appreciate everyone's help
>>> 
>> 
>> You can check if the PC is talking to the //c by doing a bare metal
>> speediboot - this will check the comms are working:
>> 
>> http://adtpro.sourceforge.net/bootstrap.html
>> 
>> Can you do a lookback test on the USB adapter by looping pins 2&3 then using
>> PuTTY to talk to itself?
>> 
>> --
>> Adrian/Witchy
>> Binary Dinosaurs creator/curator
>> Www.binarydinosaurs.co.uk - the UK's biggest private home computer
>> collection?
>> 
>> 

-- 
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?

8085 RESET

[Adrian Graham via cctalk]

Hi folks,

8085-based phone system weirdness continues and I'm beginning to wonder if
the PSU rails are all coming up in time for RESET to go high - given there's
4116 DRAMs in there isn't there supposed to be a proper power up order?

While I look at using a 20-pin ATX PSU to run this machine temporarily I
need a safe way to reset the CPU rather than constantly power cycling. The
RESET line comes from an ICL7611 op-amp via an MC14081B through pins 1-4 of
a 74LS04 and I need to pull it low for longer than 3 clock cycles.

I wish I had a schematic to show!

Cheers,

-- 
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?