Re: Calibration of 8" floppy drive?

[James Attfield]

> Date: Sat, 6 Feb 2016 00:46:33 -0500
> From: Dan K <100dash...@gmail.com>
> To: "General Discussion: On-Topic and Off-Topic Posts"
>   
> Subject: Re: Calibration of 8" floppy drive?
> Message-ID:
>5...@mail.gmail.com>
> Content-Type: text/plain; charset=UTF-8
> 
> Are there any good alternative solutions I can do to replace it? I'm
> sure I don't want the plastic touching the disk media.
> 
> -Dan

Seems like eons since I learned to align PerSci 299B's with Dysan alignment
disks and 'cat's eyes' on a 'scope :)

I echo the other sentiments here - do NOT undo or unscrew anything relating
to head positions especially involving allen (hex) screws unless you have a
'scope, an alignment disk, a very good quality set of hex screwdrivers (keys
will normally NOT suffice) and a modicum of experience. Granted, lead screw
single-headers are a little easier to do than voice-coil double-headers but
if you don't have to get into it then don't - explore all other options
first.

I'm afraid my TM-848's are double headers so the top head provides the
pressure but back when the drives were single headed felt pads did the job
of the second head. The tension was provided by the spring, the pad just
prevented scoring. I do NOT speak from experience BUT if I had to use
anything the kind of small felt pads you can get from hardware stores (e.g.
B&Q in the UK) seem remarkably similar in composition and would be worth a
try especially if you have one original to compare. Cut to shape, most are
self-adhesive too - bonus.

HTH

James

Re: Calibration of 8" floppy drive?

[Dan K]

One interesting thing I noticed (and I'm investigating at this very
moment) is the arrangement of the head load armature. A spring-loaded
arm will swing down and push the felt pad against the media, which
brings it into conformity with the head. However, there's a little
thing on the lever that touches the plastic head load mechanism that I
posted links to earlier.

When the head load solenoid is retracted, the felt pad arm is lifted
up enough that the disk can slide in and out freely. When the head
load solenoid fires, the whole thing comes down and it's clearly
supposed to push on the media. However, I think in both my drives it
doesn't touch it, or if it does it only barely touches it. I'm
thinking perhaps the armature has to come down further.

That being said, at least once I tried doing that, manually letting
the arm come down, and it didn't improve the observed behavior. It's
possible something else was happening then too, so I'll retest.

-Dan

On 2/6/16, James Attfield  wrote:
>> Date: Sat, 6 Feb 2016 00:46:33 -0500
>> From: Dan K <100dash...@gmail.com>
>> To: "General Discussion: On-Topic and Off-Topic Posts"
>>  
>> Subject: Re: Calibration of 8" floppy drive?
>> Message-ID:
>>  > 5...@mail.gmail.com>
>> Content-Type: text/plain; charset=UTF-8
>>
>> Are there any good alternative solutions I can do to replace it? I'm
>> sure I don't want the plastic touching the disk media.
>>
>> -Dan
>
> Seems like eons since I learned to align PerSci 299B's with Dysan alignment
> disks and 'cat's eyes' on a 'scope :)
>
> I echo the other sentiments here - do NOT undo or unscrew anything relating
> to head positions especially involving allen (hex) screws unless you have a
> 'scope, an alignment disk, a very good quality set of hex screwdrivers
> (keys
> will normally NOT suffice) and a modicum of experience. Granted, lead screw
> single-headers are a little easier to do than voice-coil double-headers but
> if you don't have to get into it then don't - explore all other options
> first.
>
> I'm afraid my TM-848's are double headers so the top head provides the
> pressure but back when the drives were single headed felt pads did the job
> of the second head. The tension was provided by the spring, the pad just
> prevented scoring. I do NOT speak from experience BUT if I had to use
> anything the kind of small felt pads you can get from hardware stores (e.g.
> B&Q in the UK) seem remarkably similar in composition and would be worth a
> try especially if you have one original to compare. Cut to shape, most are
> self-adhesive too - bonus.
>
> HTH
>
> James
>
>
>

Re: Calibration of 8" floppy drive?

[Dan K]

It figures: after all this talk about neither of the drives working, I
plugged one of them in (the one that's in better condition) and it now
recognizes the disk. The felt pad presses on the media, at least very
lightly, and perhaps this is the source of the main problems in the
other drive.

Other issues I didn't mention: the metal front panel that prevents the
disk drive from opening too far is broken on one of them, and the
latching mechanisms on both drives don't work, so that I have to wedge
something on top to keep the disks engaged. I also haven't tested the
reliability of the drives, as in writing a ton of data and verifying
it.

I noticed you changed the destination to cctech instead of cctalk,
James. I'll try to do that in the future for on-topic-only
discussions, as I suspect that's the custom here.

-Dan

On 2/6/16, Dan K <100dash...@gmail.com> wrote:
> One interesting thing I noticed (and I'm investigating at this very
> moment) is the arrangement of the head load armature. A spring-loaded
> arm will swing down and push the felt pad against the media, which
> brings it into conformity with the head. However, there's a little
> thing on the lever that touches the plastic head load mechanism that I
> posted links to earlier.
>
> When the head load solenoid is retracted, the felt pad arm is lifted
> up enough that the disk can slide in and out freely. When the head
> load solenoid fires, the whole thing comes down and it's clearly
> supposed to push on the media. However, I think in both my drives it
> doesn't touch it, or if it does it only barely touches it. I'm
> thinking perhaps the armature has to come down further.
>
> That being said, at least once I tried doing that, manually letting
> the arm come down, and it didn't improve the observed behavior. It's
> possible something else was happening then too, so I'll retest.
>
> -Dan
>
> On 2/6/16, James Attfield  wrote:
>>> Date: Sat, 6 Feb 2016 00:46:33 -0500
>>> From: Dan K <100dash...@gmail.com>
>>> To: "General Discussion: On-Topic and Off-Topic Posts"
>>> 
>>> Subject: Re: Calibration of 8" floppy drive?
>>> Message-ID:
>>> >> 5...@mail.gmail.com>
>>> Content-Type: text/plain; charset=UTF-8
>>>
>>> Are there any good alternative solutions I can do to replace it? I'm
>>> sure I don't want the plastic touching the disk media.
>>>
>>> -Dan
>>
>> Seems like eons since I learned to align PerSci 299B's with Dysan
>> alignment
>> disks and 'cat's eyes' on a 'scope :)
>>
>> I echo the other sentiments here - do NOT undo or unscrew anything
>> relating
>> to head positions especially involving allen (hex) screws unless you have
>> a
>> 'scope, an alignment disk, a very good quality set of hex screwdrivers
>> (keys
>> will normally NOT suffice) and a modicum of experience. Granted, lead
>> screw
>> single-headers are a little easier to do than voice-coil double-headers
>> but
>> if you don't have to get into it then don't - explore all other options
>> first.
>>
>> I'm afraid my TM-848's are double headers so the top head provides the
>> pressure but back when the drives were single headed felt pads did the
>> job
>> of the second head. The tension was provided by the spring, the pad just
>> prevented scoring. I do NOT speak from experience BUT if I had to use
>> anything the kind of small felt pads you can get from hardware stores
>> (e.g.
>> B&Q in the UK) seem remarkably similar in composition and would be worth
>> a
>> try especially if you have one original to compare. Cut to shape, most
>> are
>> self-adhesive too - bonus.
>>
>> HTH
>>
>> James
>>
>>
>>
>

Re: Programming

[nico]

Murray McCullough skrev den 2016-02-07 01:40:


On the lighter side: “Computers can never completely replace humans.
They may become capable of artificial intelligence(much in the news
today), but they will never master real stupidity.”


Or to quite a poem from my early days in programming (ca 1969) ±

I really hate this damned machine
I wish that they would sell it
it never does quite what I want
but only what I tell it

/Nico

Re: NiCd battery replacement in vintage computers

[Mark J. Blair]

I found a reference which states that the NVRAM is used to hold SCSI controller 
parameters.

I decided to mount a CR123A holder inside the case on one of the slot filler 
panels. I had some through-hole PCB mount CR123A holders left over from a 
previous project. I machined a mounting base for the holder out of a chunk of 
Delrin on my little Sherline CNC mill, with a diode installed inside the base 
to protect the battery from being charged as well as providing reverse polarity 
protection. The CR123A cells I have sitting around are 10 years old, but one of 
them will do until I buy some fresh ones.

I physically debrided the corroded copper from the top layer. I hope the rot 
didn't get into inner layers, but at least it didn't make it to the bottom of 
the board.

I posted some pictures on Twitter:

https://twitter.com/nf6x/status/696269909014159360
https://twitter.com/nf6x/status/696270186517639168
https://twitter.com/nf6x/status/696270250879234048
https://twitter.com/nf6x/status/696270706451984384
https://twitter.com/nf6x/status/696271170069405696

I haven't hooked up the machine and booted it again yet, but I can see the RTC 
oscillator running off the CR123A cell with an oscilloscope.

-- 
Mark J. Blair, NF6X 
http://www.nf6x.net/

Re: Oddball floppies for trade - 8", HS (outer edge), weird cutout

[Mattis Lind]

Hello Jay!

I think I sent a message related to these floppies before and since now is
long since the original message they're probably gone, but I need to check
to be sure.

I am interested in those oddball floppies with sector holes at the edge for
my Incoterm SPD 10/25 machine, are they still for trade?

I am not sure what you are looking for though. I do have a some HP21MX
stuff, 7900 disk cartridges. DEC stuff etc.

/Mattis

2015-10-18 1:21 GMT+02:00 Jay West :

> I have two "flippy organizers" (that's around 20 floppies each) full of
> these oddball floppies.
>
> Picture at
> https://www.flickr.com/photos/131070638@N02/22020178558/in/dateposted/
>
> They are 8", hard sectored, and the sectors are on the outer edge rather
> than the hub, and there is an odd cutout on one edge that goes inside the
> drive.
>
> I know I don't have a machine that uses these, so they are available for
> trade.
>
> J
>
>
>

Re: Oddball floppies for trade - 8", HS (outer edge), weird cutout

[Mattis Lind]

Sorry. Should have been off-list.

My fault.

/Mattis

2016-02-07 13:35 GMT+01:00 Mattis Lind :

> Hello Jay!
>
> I think I sent a message related to these floppies before and since now is
> long since the original message they're probably gone, but I need to check
> to be sure.
>
> I am interested in those oddball floppies with sector holes at the edge
> for my Incoterm SPD 10/25 machine, are they still for trade?
>
> I am not sure what you are looking for though. I do have a some HP21MX
> stuff, 7900 disk cartridges. DEC stuff etc.
>
> /Mattis
>
> 2015-10-18 1:21 GMT+02:00 Jay West :
>
>> I have two "flippy organizers" (that's around 20 floppies each) full of
>> these oddball floppies.
>>
>> Picture at
>> https://www.flickr.com/photos/131070638@N02/22020178558/in/dateposted/
>>
>> They are 8", hard sectored, and the sectors are on the outer edge rather
>> than the hub, and there is an odd cutout on one edge that goes inside the
>> drive.
>>
>> I know I don't have a machine that uses these, so they are available for
>> trade.
>>
>> J
>>
>>
>>
>

Help with getting an original Altai running: 8080A clock circuitry and MITS88 2-SIO board

[Robo58]

Hi Folks,

I'm looking for some insights in getting an original Altair running again.

My buddy asked for my help getting his Altair running again.  He went
through and replaced all the electrolytic caps, cleaned up everything and
then tried to get the MITS 88 2-SIO board to run a simple echo program.  It
wouldn't work and now I have the Altair,

I've been looking it over for about a week and I've noticed the following.

1). The 2Mhz base oscillator circuit will not reliably start up when it's
hot.  It's perfect when cool.

2). The original MITS 2-phase clock circuit was modified.  The 74123 was
replaced with a 74221 along with RC changes.  

3). The MITS 2-SIO card has two Motorola 6850 ACIA's that don't seem to do
what their data sheets say they should be doing.  


Some questions for you.  (I've searched for insights on these topics and
information is scarce).

a). Was the Altair known for hot start issue(s) ?  If so are their tried and
true fixes?

b). Going to a 74221 appears to be an excellent move.  The RC changes were
prompted by that move.  There is no longer an RC delay circuit from phase 0
to phase 1, which appears to make sense.  I don't see one-shots as a wise
clocking design choice but my buddy wants to stay with it.  Are their tried
and true fixes here?

c). I hand assembled some code to exercise the 6850.  I know it has a
software reset and then you set attributes.  I tried my buddies echo
program.  It looks for a received character and then echo's it.  I'm using a
laptop and PuTTy along with an RS-232 breakout box.  I can see characters
going in but nothing coming out.  The 6850 appears to drive the bus for a
finite amount of time and then turn off its drivers.  I don't have any
experience with the part and I don't know if that's the way it's supposed to
work or that the Altair has a bus timing issue.

Any thoughts on what I'm seeing and suggestions/fixes ?

Thanks Robo

luceracloud/seqtest - was Re: Announcing TCP/IP for RSX-11M-PLUS

[Toby Thain]

On 2015-11-08 7:50 AM, Johnny Billquist wrote:

Argh. For anyone who have downloaded the release I cut yesterday -
please get the new version (that goes for everyone else as well).

I just discovered and fixed an obscure bug that can crash the system.
It's something that happens under very specific circumstances, and is
uncommon, but if you have lots of TCP connections coming and going,
you'll hit it sooner or later.


I just found out about this.
https://github.com/luceracloud/seqtest

Would it be helpful to you?

--Toby





As usual, the distribution is available from:
ftp://mim.update.uu.se/bqtcp.dsk
ftp://mim.update.uu.se/bqtcp.tap
ftp://ftp.update.uu.se/pub/pdp11/rsx/tcpip/tcpip.dsk

The documentation is also available through ftp on Mim, or also at
http://mim.update.uu.se/tcpipdoc

 Johnny

Tired of EVERYTHING with a gear being called STEAMPUNK? Yikes I am...

[COURYHOUSE]

 
Tired of EVERYTHING with a gear being called STEAMPUNK?  Yikes I  am...
This  fun and creative video pretty much  sums   things  up!
https://www.youtube.com/watch?v=TFCuE5rHbPA
 
Enjoy -   Ed#

386 upgrade board

[Joe Giliberti]

Greetings!
I have a Televideo luggable that I have been playing with. Its a 10MHz 286
with a meg of RAM, 2 360k drives and four expansion slots. I've been trying
to figure out how capable I can make this machine for the hell of it. Did
anyone make an upgrade kit to go from a 286 to a 386? It would be
interesting to get this thing going with that, a Hard Card and an ethernet
card, somewhat capable of doing some modern tasks.

Thanks!
Joe
 This email has been sent from a
virus-free computer protected by Avast.
www.avast.com 
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Re: 386 upgrade board

[Fred Cisin]

On Sun, 7 Feb 2016, Joe Giliberti wrote:

Greetings!
I have a Televideo luggable that I have been playing with. Its a 10MHz 286
with a meg of RAM, 2 360k drives and four expansion slots. I've been trying
to figure out how capable I can make this machine for the hell of it. Did
anyone make an upgrade kit to go from a 286 to a 386? It would be
interesting to get this thing going with that, a Hard Card and an ethernet
card, somewhat capable of doing some modern tasks.


Yes, there were several.
386SX is the simplest, and can be done with a daughterboard for the 
processor, but there was at least one to full-on 386DX 16bit ISA card, 
although it also had RAM, etc. on it.


There was even an 8-bit ISA one!  I don't understand how that could work, 
unless it just used the 5160/5160 only for I/O?


PC-Elevator was one brand.

With the 286, you could run Windows 3.00, but I don't know how well the 
web browser could deal with the modern crap and bloat on the interweb.



I think that it woulod be more fun to go the other way, with something 
like Blue Thunder, to use a Z80 and CP/M.

Re: Tired of EVERYTHING with a gear being called STEAMPUNK? Yikes I am...

[Pete Turnbull]

On 07/02/2016 17:50, couryho...@aol.com wrote:


Tired of EVERYTHING with a gear being called STEAMPUNK?  Yikes I  am...
This  fun and creative video pretty much  sums   things  up!
https://www.youtube.com/watch?v=TFCuE5rHbPA


Epic!

--
Pete

The PDP11/04 has landed..

[Jos Dreesen]

Yesterday I picked up the PDP11/04 that Jay mentioned a few days ago.
Less than 15 miles from home  !

The machine spend its early days as a processor in chemical analysis apparatus, 
and was subsequently bought by the employee using it.
Before he could make use of it better, more powerful, easier to use machines 
came along and the -11 spend the next 30 years in a garage.


The -04 is an entry level machine, and the cards inside match this :

M7263 KD11 CPU
2 x M7264 16K DRAM cards
M7856 DL11 SLU/RTC
M7846 RX01 controller
2 x M7814 DZ11-F

and of course the M9301, M9302 and M9202.
Alas it has just the simple 2-switch frontpanel.

The machine also had the battery backup option, and the lead/acid batteries 
will celebrate their 40th birthday next year !
Better not try to charge them


Overall the machine is in very good condition, both CPU and RX01, and it is 
packed in a very nice half-height rack with the red PDP11 bezel at the top.
Pictures next week when the machine is cleaned and reassembled, restoration is 
to start next winter, after a house move which will nearly double working area 
for the hobby.

Many thanks to Roland for preserving the machine, and to Jay for acting as an 
interface !


Jos

Re: Help with getting an original Altai running: 8080A clock circuitry and MITS88 2-SIO board

[Brent Hilpert]

On 2016-Feb-07, at 6:17 AM, Robo58 wrote:

> c). I hand assembled some code to exercise the 6850.  I know it has a
> software reset and then you set attributes.  I tried my buddies echo
> program.  It looks for a received character and then echo's it.  I'm using a
> laptop and PuTTy along with an RS-232 breakout box.  I can see characters
> going in but nothing coming out.  The 6850 appears to drive the bus for a
> finite amount of time and then turn off its drivers.  I don't have any
> experience with the part and I don't know if that's the way it's supposed to
> work or that the Altair has a bus timing issue.

How about doing a program that simply repeatedly outputs a character first, 
getting that going before trying to deal with input - cuts the problem space in 
half.
The repeat loop should give you some consistent bus activity and observable 
waveforms on a scope if you have one, rather than trying to catch events 
initiated from external input activity.

RE: The PDP11/04 has landed..

[Jay West]

Jos wrote...
--
restoration is to start next winter, after a house move which will nearly 
double working area for the hobby.
--
Bhahahahaha From experience... it will never be enough space. Double it 
again. Still won't be enough. These things reproduce *grin*

J

RE: Help with getting an original Altai running: 8080A clock circuitry and MITS88 2-SIO board

[Kip Koon]

Hi Guys,

I also have an original Altair 8800 that has not been powered up since I was
in my late teens or early twenties.  I'm 56 now and I was wondering if
anyone has put together a document for successfully restoring Altair
computers specifically and retro style computers in general.  Any help is
much appreciated.  I have a bunch of boards in mine.  Here are the pictures.

< https://www.dropbox.com/sh/88mp9wna3myb2ce/AABcNr_ne3ssgVSxR-_YiASva?dl=0>

Any help is greatly appreciated.

 

Kip Koon

computer...@sc.rr.com

http://www.cocopedia.com/wiki/index.php/Kip_Koon

 

Re: Tired of EVERYTHING with a gear being called STEAMPUNK? Yikes I am...

[COURYHOUSE]

I  am  very envious of the animators skills on those  singing  people in 
the still portraits..
Heh  is there any easy  way to  do  this?   Ed#
 
 
In a message dated 2/7/2016 1:13:03 P.M. US Mountain Standard Time,  
p...@dunnington.plus.com writes:

On  07/02/2016 17:50, couryho...@aol.com wrote:
>
> Tired of  EVERYTHING with a gear being called STEAMPUNK?  Yikes I   am...
> This  fun and creative video pretty much   sums   things  up!
>  https://www.youtube.com/watch?v=TFCuE5rHbPA

Epic!

--  
Pete

Re: Help with getting an original Altai running: 8080A clock circuitry and MITS88 2-SIO board

[drlegendre .]

I'll not pretend to be any sort of Altair expert, but I did manage a fairly
involved rebuild / restoration of one, about a year back. Here's a link to
the set of documents I collected in the process:

https://nerp.net/~legendre/altair/

My machine is restored to what you might call a "freshly built" state, so
the only boards present are the 8080A CPU and a third-party SRAM board. The
front panel is also re-installed and working.

I haven't been able to find (afford..) a genuine MITS RAM board for it,
much as I'd like one. =/

On Sun, Feb 7, 2016 at 4:23 PM, Kip Koon  wrote:

> Hi Guys,
>
> I also have an original Altair 8800 that has not been powered up since I
> was
> in my late teens or early twenties.  I'm 56 now and I was wondering if
> anyone has put together a document for successfully restoring Altair
> computers specifically and retro style computers in general.  Any help is
> much appreciated.  I have a bunch of boards in mine.  Here are the
> pictures.
>
> <
> https://www.dropbox.com/sh/88mp9wna3myb2ce/AABcNr_ne3ssgVSxR-_YiASva?dl=0>
>
> Any help is greatly appreciated.
>
>
>
> Kip Koon
>
> computer...@sc.rr.com
>
> http://www.cocopedia.com/wiki/index.php/Kip_Koon
>
>
>
>

Re: Help with getting an original Altai running: 8080A clock circuitry and MITS88 2-SIO board

[Eric Smith]

On Sun, Feb 7, 2016 at 3:23 PM, Kip Koon  wrote:
> I also have an original Altair 8800 that has not been powered up since I was
> in my late teens or early twenties.  I'm 56 now and I was wondering if
> anyone has put together a document for successfully restoring Altair
> computers specifically and retro style computers in general.

IMPORTANT: Do NOT power up until you've tested the DC power supplies
*without* the boards installed. Check DC voltages and ripple. Aluminum
electrolytic filter capacitors may need to be reformed or replaced.
(But let's not restart the argument about which to do!)

Re: 386 upgrade board

[Joe Giliberti]

That's good to know that they are out there. If anyone has one they would
be willing to part with, please let me know. I'm also in the market for an
ISA hard card if anyone has one.

Thanks,
Joe
 This email has been sent from a
virus-free computer protected by Avast.
www.avast.com 
<#DDB4FAA8-2DD7-40BB-A1B8-4E2AA1F9FDF2>

On Sun, Feb 7, 2016 at 2:53 PM, Fred Cisin  wrote:

> On Sun, 7 Feb 2016, Joe Giliberti wrote:
>
>> Greetings!
>> I have a Televideo luggable that I have been playing with. Its a 10MHz 286
>> with a meg of RAM, 2 360k drives and four expansion slots. I've been
>> trying
>> to figure out how capable I can make this machine for the hell of it. Did
>> anyone make an upgrade kit to go from a 286 to a 386? It would be
>> interesting to get this thing going with that, a Hard Card and an ethernet
>> card, somewhat capable of doing some modern tasks.
>>
>
> Yes, there were several.
> 386SX is the simplest, and can be done with a daughterboard for the
> processor, but there was at least one to full-on 386DX 16bit ISA card,
> although it also had RAM, etc. on it.
>
> There was even an 8-bit ISA one!  I don't understand how that could work,
> unless it just used the 5160/5160 only for I/O?
>
> PC-Elevator was one brand.
>
> With the 286, you could run Windows 3.00, but I don't know how well the
> web browser could deal with the modern crap and bloat on the interweb.
>
>
> I think that it woulod be more fun to go the other way, with something
> like Blue Thunder, to use a Z80 and CP/M.
>
>
>

Re: Help with getting an original Altai running: 8080A clock circuitry and MITS88 2-SIO board

[drlegendre .]

Good point.. and if you have the later PSU with the 95,000uF 12V cap, pay
close attention to that guy.

FYI, power supplies in the Altair typically work like this: In the chassis,
there are two regulated +18 / -18V supplies of 1A each, and an unregulated
~8V supply capable of substantial current. On the individual boards, the 8V
supply is commonly regulated down to 5V (with 7805, etc.) and when needed,
the +/-18V supplies to +12V / -12V with simple zener diode shunt circuits.

On Sun, Feb 7, 2016 at 4:43 PM, Eric Smith  wrote:

> On Sun, Feb 7, 2016 at 3:23 PM, Kip Koon  wrote:
> > I also have an original Altair 8800 that has not been powered up since I
> was
> > in my late teens or early twenties.  I'm 56 now and I was wondering if
> > anyone has put together a document for successfully restoring Altair
> > computers specifically and retro style computers in general.
>
> IMPORTANT: Do NOT power up until you've tested the DC power supplies
> *without* the boards installed. Check DC voltages and ripple. Aluminum
> electrolytic filter capacitors may need to be reformed or replaced.
> (But let's not restart the argument about which to do!)
>

RE: Help with getting an original Altai running: 8080A clock circuitry and MITS88 2-SIO board

[Kip Koon]

Hi drlegendre,
Care go be a sounding board/technician troubleshooter when the time comes for 
me to start this journey?  :)  

Kip Koon
computer...@sc.rr.com
http://www.cocopedia.com/wiki/index.php/Kip_Koon



> -Original Message-
> From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of drlegendre .
> Sent: Sunday, February 07, 2016 5:39 PM
> To: General Discussion: On-Topic and Off-Topic Posts
> Subject: Re: Help with getting an original Altai running: 8080A clock 
> circuitry and MITS88 2-SIO board
> 
> I'll not pretend to be any sort of Altair expert, but I did manage a fairly 
> involved rebuild / restoration of one, about a year back. Here's
> a link to the set of documents I collected in the process:
> 
> https://nerp.net/~legendre/altair/
> 
> My machine is restored to what you might call a "freshly built" state, so the 
> only boards present are the 8080A CPU and a third-party
> SRAM board. The front panel is also re-installed and working.
> 
> I haven't been able to find (afford..) a genuine MITS RAM board for it, much 
> as I'd like one. =/
> 
> On Sun, Feb 7, 2016 at 4:23 PM, Kip Koon  wrote:
> 
> > Hi Guys,
> >
> > I also have an original Altair 8800 that has not been powered up since
> > I was in my late teens or early twenties.  I'm 56 now and I was
> > wondering if anyone has put together a document for successfully
> > restoring Altair computers specifically and retro style computers in
> > general.  Any help is much appreciated.  I have a bunch of boards in
> > mine.  Here are the pictures.
> >
> > <
> > https://www.dropbox.com/sh/88mp9wna3myb2ce/AABcNr_ne3ssgVSxR-_YiASva?d
> > l=0>
> >
> > Any help is greatly appreciated.
> >
> >
> >
> > Kip Koon
> >
> > computer...@sc.rr.com
> >
> > http://www.cocopedia.com/wiki/index.php/Kip_Koon
> >
> >
> >
> >

Re: Help with getting an original Altai running: 8080A clock circuitry and MITS88 2-SIO board

[drlegendre .]

Sure, I'm glad to help - but bear in mind that I'm a technician, not an
engineer - and solid-state logic isn't even my field! ;-)

And please don't leave the other members out of the loop - they're some of
the guys who helped +me+ through +my+ project..



On Sun, Feb 7, 2016 at 5:04 PM, Kip Koon  wrote:

> Hi drlegendre,
> Care go be a sounding board/technician troubleshooter when the time comes
> for me to start this journey?  :)
>
> Kip Koon
> computer...@sc.rr.com
> http://www.cocopedia.com/wiki/index.php/Kip_Koon
>
>
>
> > -Original Message-
> > From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of
> drlegendre .
> > Sent: Sunday, February 07, 2016 5:39 PM
> > To: General Discussion: On-Topic and Off-Topic Posts
> > Subject: Re: Help with getting an original Altai running: 8080A clock
> circuitry and MITS88 2-SIO board
> >
> > I'll not pretend to be any sort of Altair expert, but I did manage a
> fairly involved rebuild / restoration of one, about a year back. Here's
> > a link to the set of documents I collected in the process:
> >
> > https://nerp.net/~legendre/altair/
> >
> > My machine is restored to what you might call a "freshly built" state,
> so the only boards present are the 8080A CPU and a third-party
> > SRAM board. The front panel is also re-installed and working.
> >
> > I haven't been able to find (afford..) a genuine MITS RAM board for it,
> much as I'd like one. =/
> >
> > On Sun, Feb 7, 2016 at 4:23 PM, Kip Koon  wrote:
> >
> > > Hi Guys,
> > >
> > > I also have an original Altair 8800 that has not been powered up since
> > > I was in my late teens or early twenties.  I'm 56 now and I was
> > > wondering if anyone has put together a document for successfully
> > > restoring Altair computers specifically and retro style computers in
> > > general.  Any help is much appreciated.  I have a bunch of boards in
> > > mine.  Here are the pictures.
> > >
> > > <
> > > https://www.dropbox.com/sh/88mp9wna3myb2ce/AABcNr_ne3ssgVSxR-_YiASva?d
> > > l=0>
> > >
> > > Any help is greatly appreciated.
> > >
> > >
> > >
> > > Kip Koon
> > >
> > > computer...@sc.rr.com
> > >
> > > http://www.cocopedia.com/wiki/index.php/Kip_Koon
> > >
> > >
> > >
> > >
>
>

RE: Help with getting an original Altai running: 8080A clock circuitry and MITS88 2-SIO board

[Kip Koon]

Hi drlegendre,
Sure, that's fine with me.  I'll let you know when I start.  I'm thinking the 
PS is the first thing to check.  I wonder how the caps are doing, or should I 
get a nice modern switching power supply.  

Kip Koon
computer...@sc.rr.com
http://www.cocopedia.com/wiki/index.php/Kip_Koon



> -Original Message-
> From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of drlegendre .
> Sent: Sunday, February 07, 2016 6:18 PM
> To: General Discussion: On-Topic and Off-Topic Posts
> Subject: Re: Help with getting an original Altai running: 8080A clock 
> circuitry and MITS88 2-SIO board
> 
> Sure, I'm glad to help - but bear in mind that I'm a technician, not an 
> engineer - and solid-state logic isn't even my field! ;-)
> 
> And please don't leave the other members out of the loop - they're some of 
> the guys who helped +me+ through +my+ project..
> 
> 
> 
> On Sun, Feb 7, 2016 at 5:04 PM, Kip Koon  wrote:
> 
> > Hi drlegendre,
> > Care go be a sounding board/technician troubleshooter when the time
> > comes for me to start this journey?  :)
> >
> > Kip Koon
> > computer...@sc.rr.com
> > http://www.cocopedia.com/wiki/index.php/Kip_Koon
> >
> >
> >
> > > -Original Message-
> > > From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of
> > drlegendre .
> > > Sent: Sunday, February 07, 2016 5:39 PM
> > > To: General Discussion: On-Topic and Off-Topic Posts
> > > Subject: Re: Help with getting an original Altai running: 8080A
> > > clock
> > circuitry and MITS88 2-SIO board
> > >
> > > I'll not pretend to be any sort of Altair expert, but I did manage a
> > fairly involved rebuild / restoration of one, about a year back.
> > Here's
> > > a link to the set of documents I collected in the process:
> > >
> > > https://nerp.net/~legendre/altair/
> > >
> > > My machine is restored to what you might call a "freshly built"
> > > state,
> > so the only boards present are the 8080A CPU and a third-party
> > > SRAM board. The front panel is also re-installed and working.
> > >
> > > I haven't been able to find (afford..) a genuine MITS RAM board for
> > > it,
> > much as I'd like one. =/
> > >
> > > On Sun, Feb 7, 2016 at 4:23 PM, Kip Koon  wrote:
> > >
> > > > Hi Guys,
> > > >
> > > > I also have an original Altair 8800 that has not been powered up
> > > > since I was in my late teens or early twenties.  I'm 56 now and I
> > > > was wondering if anyone has put together a document for
> > > > successfully restoring Altair computers specifically and retro
> > > > style computers in general.  Any help is much appreciated.  I have
> > > > a bunch of boards in mine.  Here are the pictures.
> > > >
> > > > <
> > > > https://www.dropbox.com/sh/88mp9wna3myb2ce/AABcNr_ne3ssgVSxR-_YiAS
> > > > va?d
> > > > l=0>
> > > >
> > > > Any help is greatly appreciated.
> > > >
> > > >
> > > >
> > > > Kip Koon
> > > >
> > > > computer...@sc.rr.com
> > > >
> > > > http://www.cocopedia.com/wiki/index.php/Kip_Koon
> > > >
> > > >
> > > >
> > > >
> >
> >

RE: Help with getting an original Altai running: 8080A clock circuitry and MITS88 2-SIO board

[Robo58]

Hi Brent, Drlegendre and Eric

Brent:  I took your advice and did a little program to output "A"'s and
monitoring Transmitter empty before looping again.  That works fine and it
will run for hours.

Drlegendre:  Thanks for the excellent document link.  My buddy has the MITS
1K static ram and the MITS 4K dynamic ram cards.  I've been doing my testing
with the 1K static ram to limit potential problems.

Eric:  This Altair has the smaller PS with the smaller Electrolytic caps.
They were all replaced and the PS brought up without cards with a Variac.
My buddy bought Kemet Capacitors on the basis of very good ripple current
rating and low ESR.


Thanks Ron

   

-Original Message-
From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Brent
Hilpert
Sent: Sunday, February 7, 2016 4:14 PM
To: General Discussion: On-Topic and Off-Topic Posts 
Subject: Re: Help with getting an original Altai running: 8080A clock
circuitry and MITS88 2-SIO board

On 2016-Feb-07, at 6:17 AM, Robo58 wrote:

> c). I hand assembled some code to exercise the 6850.  I know it has a 
> software reset and then you set attributes.  I tried my buddies echo 
> program.  It looks for a received character and then echo's it.  I'm 
> using a laptop and PuTTy along with an RS-232 breakout box.  I can see 
> characters going in but nothing coming out.  The 6850 appears to drive 
> the bus for a finite amount of time and then turn off its drivers.  I 
> don't have any experience with the part and I don't know if that's the 
> way it's supposed to work or that the Altair has a bus timing issue.

How about doing a program that simply repeatedly outputs a character first,
getting that going before trying to deal with input - cuts the problem space
in half.
The repeat loop should give you some consistent bus activity and observable
waveforms on a scope if you have one, rather than trying to catch events
initiated from external input activity.

Re: Help with getting an original Altai running: 8080A clock circuitry and MITS88 2-SIO board

[drlegendre .]

Kip,

Assuming the initial visual inspection goes well, the PSU is +always+ the
first thing to check.. and that goes for everything from digital computers
to vacuum-tube radios.

Do you have a general background in electrical / electronic
troubleshooting? Do you have a Variac on-hand, or at least a
current-limited AC supply - such as the old light bulb socket in-series, as
was popular in the days before Variacs became affordable to the common man?

On Sun, Feb 7, 2016 at 6:15 PM, Robo58  wrote:

> Hi Brent, Drlegendre and Eric
>
> Brent:  I took your advice and did a little program to output "A"'s and
> monitoring Transmitter empty before looping again.  That works fine and it
> will run for hours.
>
> Drlegendre:  Thanks for the excellent document link.  My buddy has the MITS
> 1K static ram and the MITS 4K dynamic ram cards.  I've been doing my
> testing
> with the 1K static ram to limit potential problems.
>
> Eric:  This Altair has the smaller PS with the smaller Electrolytic caps.
> They were all replaced and the PS brought up without cards with a Variac.
> My buddy bought Kemet Capacitors on the basis of very good ripple current
> rating and low ESR.
>
>
> Thanks Ron
>
>
>
> -Original Message-
> From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Brent
> Hilpert
> Sent: Sunday, February 7, 2016 4:14 PM
> To: General Discussion: On-Topic and Off-Topic Posts <
> cctalk@classiccmp.org>
> Subject: Re: Help with getting an original Altai running: 8080A clock
> circuitry and MITS88 2-SIO board
>
> On 2016-Feb-07, at 6:17 AM, Robo58 wrote:
>
> > c). I hand assembled some code to exercise the 6850.  I know it has a
> > software reset and then you set attributes.  I tried my buddies echo
> > program.  It looks for a received character and then echo's it.  I'm
> > using a laptop and PuTTy along with an RS-232 breakout box.  I can see
> > characters going in but nothing coming out.  The 6850 appears to drive
> > the bus for a finite amount of time and then turn off its drivers.  I
> > don't have any experience with the part and I don't know if that's the
> > way it's supposed to work or that the Altair has a bus timing issue.
>
> How about doing a program that simply repeatedly outputs a character first,
> getting that going before trying to deal with input - cuts the problem
> space
> in half.
> The repeat loop should give you some consistent bus activity and observable
> waveforms on a scope if you have one, rather than trying to catch events
> initiated from external input activity.
>
>
>
>
>

Re: Help with getting an original Altai running: 8080A clock circuitry and MITS88 2-SIO board

[drlegendre .]

Pardon this, it was meant to be part of the previous message..

Kip, a modern switching supply won't really win you anything, and IMO, kind
of wrecks the look (and the vintage fun)..

Again, the only regulated supplies produced in the chassis are the +/-18V
and they are limited to 1A. I believe the original design calls for zener
regs controlling pass transistors, but if you're looking for an upgrade,
it's quite reasonable to replace them with the 7818 (+18) and 7918 (-18)
three-pin regulator packs. No muss, no fuss.. built in current and thermal
limiting, and cheap to boot.

And the ~8V supply is a simple one-stage design. Xfmr secondary -> 30A 50V
bridge -> 95,000uF 3" computer-grade bulk capacitor filter.. that's it. At
the most, you'll need a new cap and a $5 bridge pack. Regulating it gets
you nothing, as each card has at least one independent 5V regulator. For
example, my 16K SRAM card actually has 4x 7805 5V regs, one for each of the
four 4K banks.

On Sun, Feb 7, 2016 at 7:51 PM, drlegendre .  wrote:

> Kip,
>
> Assuming the initial visual inspection goes well, the PSU is +always+ the
> first thing to check.. and that goes for everything from digital computers
> to vacuum-tube radios.
>
> Do you have a general background in electrical / electronic
> troubleshooting? Do you have a Variac on-hand, or at least a
> current-limited AC supply - such as the old light bulb socket in-series, as
> was popular in the days before Variacs became affordable to the common man?
>
> On Sun, Feb 7, 2016 at 6:15 PM, Robo58  wrote:
>
>> Hi Brent, Drlegendre and Eric
>>
>> Brent:  I took your advice and did a little program to output "A"'s and
>> monitoring Transmitter empty before looping again.  That works fine and it
>> will run for hours.
>>
>> Drlegendre:  Thanks for the excellent document link.  My buddy has the
>> MITS
>> 1K static ram and the MITS 4K dynamic ram cards.  I've been doing my
>> testing
>> with the 1K static ram to limit potential problems.
>>
>> Eric:  This Altair has the smaller PS with the smaller Electrolytic caps.
>> They were all replaced and the PS brought up without cards with a Variac.
>> My buddy bought Kemet Capacitors on the basis of very good ripple current
>> rating and low ESR.
>>
>>
>> Thanks Ron
>>
>>
>>
>> -Original Message-
>> From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Brent
>> Hilpert
>> Sent: Sunday, February 7, 2016 4:14 PM
>> To: General Discussion: On-Topic and Off-Topic Posts <
>> cctalk@classiccmp.org>
>> Subject: Re: Help with getting an original Altai running: 8080A clock
>> circuitry and MITS88 2-SIO board
>>
>> On 2016-Feb-07, at 6:17 AM, Robo58 wrote:
>>
>> > c). I hand assembled some code to exercise the 6850.  I know it has a
>> > software reset and then you set attributes.  I tried my buddies echo
>> > program.  It looks for a received character and then echo's it.  I'm
>> > using a laptop and PuTTy along with an RS-232 breakout box.  I can see
>> > characters going in but nothing coming out.  The 6850 appears to drive
>> > the bus for a finite amount of time and then turn off its drivers.  I
>> > don't have any experience with the part and I don't know if that's the
>> > way it's supposed to work or that the Altair has a bus timing issue.
>>
>> How about doing a program that simply repeatedly outputs a character
>> first,
>> getting that going before trying to deal with input - cuts the problem
>> space
>> in half.
>> The repeat loop should give you some consistent bus activity and
>> observable
>> waveforms on a scope if you have one, rather than trying to catch events
>> initiated from external input activity.
>>
>>
>>
>>
>>
>

Re: Tired of EVERYTHING with a gear being called STEAMPUNK? Yikes I am...

[dwight]

I'm just tired of seeing really nice clocks turned into
a pile of junk.
Dwight



From: cctalk  on behalf of Pete Turnbull 

Sent: Sunday, February 7, 2016 12:00 PM
To: cctalk@classiccmp.org
Subject: Re: Tired of EVERYTHING with a gear being called STEAMPUNK? Yikes I 
am...

On 07/02/2016 17:50, couryho...@aol.com wrote:
>
> Tired of EVERYTHING with a gear being called STEAMPUNK?  Yikes I  am...
> This  fun and creative video pretty much  sums   things  up!
> https://www.youtube.com/watch?v=TFCuE5rHbPA

Epic!

--
Pete

Re: The PDP11/04 has landed..

[Richard Loken]

On Sun, 7 Feb 2016, Jos Dreesen wrote:


Yesterday I picked up the PDP11/04 that Jay mentioned a few days ago.
Less than 15 miles from home  !


First week on the job in March 1980, my new boss brought me two pdp11/04s
and a box of memeory chips.  He to told me to double the memory in
the two computers by populating all the empty holes on the memory boards.

Fortunately I started with only one memory board.

All the holes were full of solder so I tried to clear the solder before
putting in the chips.  It seemed that every time I touched the soldering
iron to the board, any nearby traces immediately lifted and rolled up.
I never finished the first board and I never started the second board.

Up until then I thought I knew how to solder.

--
  Richard Loken VE6BSV, Systems Programmer - VMS   : "...underneath those
  Athabasca University : tuques we wear, our
  Athabasca, Alberta Canada: heads are naked!"
  ** rllo...@telus.net ** :- Arthur Black

RE: The PDP11/04 has landed..

[Robert Jarratt]

> -Original Message-
> From: cctech [mailto:cctech-boun...@classiccmp.org] On Behalf Of Jos
> Dreesen
> Sent: 07 February 2016 17:55
> To: classic...@classiccmp.org
> Subject: The PDP11/04 has landed..
> 
> 
> 
> Yesterday I picked up the PDP11/04 that Jay mentioned a few days ago.
> Less than 15 miles from home  !
> 
> The machine spend its early days as a processor in chemical analysis
> apparatus, and was subsequently bought by the employee using it.
> Before he could make use of it better, more powerful, easier to use
> machines came along and the -11 spend the next 30 years in a garage.
> 
> 
> The -04 is an entry level machine, and the cards inside match this :
> 
>  M7263 KD11 CPU
> 2 x M7264 16K DRAM cards
>  M7856 DL11 SLU/RTC
>  M7846 RX01 controller
> 2 x M7814 DZ11-F
> 
> and of course the M9301, M9302 and M9202.
> Alas it has just the simple 2-switch frontpanel.
> 
> The machine also had the battery backup option, and the lead/acid batteries
> will celebrate their 40th birthday next year !
> Better not try to charge them
> 
> 
> Overall the machine is in very good condition, both CPU and RX01, and it is
> packed in a very nice half-height rack with the red PDP11 bezel at the top.
> Pictures next week when the machine is cleaned and reassembled,
> restoration is to start next winter, after a house move which will nearly
> double working area for the hobby.
> 
> Many thanks to Roland for preserving the machine, and to Jay for acting as an
> interface !
> 


I have one of these on my restoration list. I know the PSU does not work, and 
that others have tried to fix it before me, who probably know PSUs much better 
than I do. It has core memory so I really would like to get his one fixed. I 
have never seen a PSU for it come available in the UK or Europe, so it looks 
like it won't be an easy job. :-(

Regards

Rob