Re: dfitoimd: decoding Intel M2FM floppy flux images (was Re: Intel 432 floppy flux images for decoding)

[Chuck Guzis]

On 08/08/2016 11:48 PM, Eric Smith wrote:
> On Mon, Aug 8, 2016 at 11:06 PM, Chuck Guzis 
> wrote:

>> At the expense of sounding like a complete idiot, have you checked
>> the alignment of the drive?
> 
> I can't. I only have the images.

That's unfortunate.  I run into mis-aligned disks not infrequently.  I
don't know how to correct that one with software.  When making cw-type
images, you can usually just inspect the histogram for a track and tell
by the groupings whether you're on track or not.

--Chuck

RE: HP 110 AC Adapter

[Martin.Hepperle]

Josh,

for testing you can also remove the battery and connect a 6V DC power supply
to the computer.
Under the battery cover there is also a picofuse which may be blown if
someone was tinkering with the machine before.

The HP 110 is interesting if you want to play with HP-IL - it has some BIOS
routines to control the HP-IL. The other remarkable thing is that he has
MS-DOS in ROM and all data on RAM disks m(which is rather limited, though).
Ideally you would also want a 9114 3-1/2" floppy disk drive for it.

If the computer works, you can rebuild the battery pack.  The lead cells are
still available e.g. under the name Hawker Enersys Cyclone 2V/2.5Ah. You can
use 3 single cells (about 7$ each) and make them into a pack.

Good luck
Martin

Re: CCS S-100 system avail in Minneapolis

[drlegendre .]

mailed.

On Mon, Aug 8, 2016 at 10:01 AM, william degnan 
wrote:

> I was contacted about a CCS S-100 system available for pickup in
> the Minneapolis area.  Contact me privately.  Includes CP/M software, etc.
> A full station wagon full of stuff/docs.  I don't know the guy, just trying
> to help out.
>
> http://www.vintagecomputer.net/contact.cfm
>
> Bill
>

Re: SWTPC 6800

[Ethan Dicks]

On Fri, Aug 5, 2016 at 6:55 PM, Chuck Guzis  wrote:
> On 08/05/2016 02:15 PM, Brad H wrote:
>> I have one more question for you guys -- I have a few CT-1024
>> terminals and would really like this system to work with one of
>> those.  However, all of the CTs are quite delicate and are set I
>> think for 7, E, 2 @ 110 baud via soldered jumpers.
>
> Well, 110 bps is a bit on the slow side--great for teletypes, not so
> much for video terminals.

And I am not aware of any USB serial adapters that do 110 bps.  If
anyone knows of any, post brand and model numbers.

-ethan

Re: SWTPC 6800

[Ethan Dicks]

On Fri, Aug 5, 2016 at 2:58 PM, Chris Elmquist  wrote:
> On Friday (08/05/2016 at 06:50PM +), tony duell wrote:
>>
>> Am I the only person who rarely, if ever, has RS232 problems?
>
> No.  ;-)

No, but I used to manufacture sync serial hardware and have deep
knowledge of how async serial in general, and RS-232/EIA works in
particular, and still have all the test gear from 30 years ago.  I get
why people find serial comms frustrating and do not take my
experiences as "typical".

I pretty much don't hook up anything new that isn't on a "traffic
light".  I have several - DE9-DE9 for modern stuff, and multiple
DB25-DB25 for old and new stuff.  *Mostly*, if you plug everything in
and you get at least TxD and RxD to light up, you at least have
figured out where the primary gozintas and gozoutas go and can stop
adding null-modem adapters.  Past that, you have to know if either end
requires hardware handshaking and either plumb the right signals
(vintage setup documentation is invaluable for this) or bridge the
appropriate lines (documentation again) so that one or both sides
_thinks_ there's hardware handshaking.  If you defeat it, you might
run into overrun conditions, but at least you should be able to
establish basic comms and pass a few characters.  To that end, you do
have to match speeds on both sides, and the usual best place to start
is 8-N-1 for data bits, parity, and stop bits.  I've run into multiple
situations where 7-E-1 or 7-N-1 is the right answer.  With enough
experience, the "baud barf" from mismatched speeds takes on an often
recognizable pattern that can be used to quickly figure out what the
speed ought to be, but lacking instrumentation like a serial analyzer
or an oscilloscope, one can try "all the speeds" until cleartext comes
through.  I also try the speeds in "most popular order", 9600, 1200,
300, 2400, 4800, 19200, 600... in the hopes of saving time.  Every
once in a while, you run into some oddball stuff, like 9600/150, etc.,
split speeds from the days of timesharing setups where the CPU wanted
to get data to the users as fast as possible but wanted to minimize
input interrupts and more closely match the input flow to (slow) human
typing speeds.  This wasn't common with microcomputers, but I've seen
it with PDP-11 and PDP-8 setups and isn't something to look for first,
but it does exist and highlights how strange things can get if all
you've ever done is plug a high speed modem into a PC for dial-up
internet.

One important tip about USB serial dongles (and some laptops DE9
serial ports) - I've had problems with some of them and 1970s gear
because the EIA/RS-232C (1969) level specification is +5V to +15V for
space (0) and -15V to -5V for mark (1) (with +/-3V min sensitivity)
and a lot of old gear is expecting +/-12V and not happy with
lower-voltage lines and thin wires that don't help signal losses.  One
case in particular was a 1977-era Bridgeport Series II CNC mill with a
LSI-11/03 CPU and a lot of custom Bridgeport boards.  Everyone else
who tried to talk to the Bridgeport before me had zero success.  I
checked all the things on the list and finally pulled out the laptop
and set up a Dell desktop which worked the first time.  When
connecting to pre-1982 gear, I'd definitely try it from a desktop if a
laptop is just not working.  Checking the lines with an oscilloscope
could also help verify this what's giving the grief (I did not have
one handy when we were trying to get that CNC mill working).

In terms of serial analyzers, there are several types out there, and
the ones that I've had the most time on are the HP 4951/4952 series.
There are different models with different features, but if you are
going to shop for one, ensure it comes with the "keyboard lid" because
that's where the line drivers and serial connectors are.  The large
connector on the back goes to a "pod" that happens to snap on the
front of the unit when the keyboard is flipped up.  It's much easier
to find the base units than loose pods, IME.  Check which pod.  I've
seen many with DB25s, which is probably what you want, but I've also
seen DC-37 connectors, and non-EIA (RS-232) level shifters.  The good
news is that among these different models, the pods should be
interchangable, so if you end up picking up 2 units (not unusual) with
different base capabilities (some have DC-150 cassette tape, some have
3.5" floppy, plus some minor differences) and only one has a DB25 EIA
pod, you can at least migrate it between the units.  I find the serial
analyzers invaluable for snooping on the details of what's happening
on the wire, but any analyzers I have seen have a handy "autoconfig"
button to sniff traffic and configure the line for monitoring, so it's
often a quick click to get all the parameters if you don't already
know them.  Where they really shine is looking for troubles at the
application layer, debugging Kermit or XMODEM traffic that isn't
working for any obvious reason.  The advanced stuff you can do is to
writ

Re: dfitoimd: decoding Intel M2FM floppy flux images (was Re: Intel 432 floppy flux images for decoding)

[dwight]

I was having problems recovering inner tracks on some 5.25 disk. I added some 
extra screws that allowed me to move the head both radially and up and down.

I was able to recover more but still didn't get it all.

The up and down allowed a little rotation as well as tracking.

On the inner tracks a small up or down looks like the head is

rotated slightly.

I just looked at the analog amplitude. I was just using a controller

card instead of sampling.

Dwight


From: cctalk  on behalf of Chuck Guzis 

Sent: Tuesday, August 9, 2016 12:33:24 AM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: dfitoimd: decoding Intel M2FM floppy flux images (was Re: Intel 
432 floppy flux images for decoding)

On 08/08/2016 11:48 PM, Eric Smith wrote:
> On Mon, Aug 8, 2016 at 11:06 PM, Chuck Guzis 
> wrote:

>> At the expense of sounding like a complete idiot, have you checked
>> the alignment of the drive?
>
> I can't. I only have the images.

That's unfortunate.  I run into mis-aligned disks not infrequently.  I
don't know how to correct that one with software.  When making cw-type
images, you can usually just inspect the histogram for a track and tell
by the groupings whether you're on track or not.

--Chuck

Re: SWTPC 6800

[Brent Hilpert]

On 2016-Aug-09, at 6:47 AM, Ethan Dicks wrote:
> On Fri, Aug 5, 2016 at 6:55 PM, Chuck Guzis  wrote:
>> On 08/05/2016 02:15 PM, Brad H wrote:
>>> I have one more question for you guys -- I have a few CT-1024
>>> terminals and would really like this system to work with one of
>>> those.  However, all of the CTs are quite delicate and are set I
>>> think for 7, E, 2 @ 110 baud via soldered jumpers.
>> 
>> Well, 110 bps is a bit on the slow side--great for teletypes, not so
>> much for video terminals.
> 
> And I am not aware of any USB serial adapters that do 110 bps.  If
> anyone knows of any, post brand and model numbers.

It didn't do 110, but I chanced across one USB/serial adapter that goes down to 
75 bps.
which fortuitously was just what I needed at the time for the model 28 teletype 
(with the appropriate gears) I was attempting to drive.

The 75 wasn't readily accessible, I had to go to a low level in the unix config 
code and try sequential factors in the
configuration for the rate, 75 being another factor of 2 down in the standard 
rate series 19,200 . . 9600 . . 1200 . . 300 . . 150 . . 

Re: SWTPC 6800

[Brad H]

I think for me what gets confusing is where the various pins are.  I have to 
read and re-resd pinouts to figure out where stuff should be.  I sometimes have 
a brain fart and get it backwards.  Yesterday part of my problem with my 
Tektronix box was having the numbering of pins on the terminal's DB25 
backwards.  Once I had that figured out it was just a matter of looping certain 
pins and we were good.  It just adds an extra layer of fiddling.
I have a question though.. there have been a few times where I thought the 6800 
crashed but may not have.  In several cases.. I sent a large loader file across 
and noticed errors coming through.. so I'd stop the machine.  This was after 
teraterm said it had sent everything through.  Is it possible the serial port 
on my PC is still trying to send out garbage for a while, messing up my 
connection to the 6800 until it finishes?  I kept moving cards around but 
eventually it seemed to start working after so many powerups and time had 
passed..




Sent from my Samsung device

 Original message 
From: Brent Hilpert  
Date: 2016-08-09  9:49 AM  (GMT-08:00) 
To: "General Discussion: On-Topic and Off-Topic Posts"  
Subject: Re: SWTPC 6800 

On 2016-Aug-09, at 6:47 AM, Ethan Dicks wrote:
> On Fri, Aug 5, 2016 at 6:55 PM, Chuck Guzis  wrote:
>> On 08/05/2016 02:15 PM, Brad H wrote:
>>> I have one more question for you guys -- I have a few CT-1024
>>> terminals and would really like this system to work with one of
>>> those.  However, all of the CTs are quite delicate and are set I
>>> think for 7, E, 2 @ 110 baud via soldered jumpers.
>> 
>> Well, 110 bps is a bit on the slow side--great for teletypes, not so
>> much for video terminals.
> 
> And I am not aware of any USB serial adapters that do 110 bps.  If
> anyone knows of any, post brand and model numbers.

It didn't do 110, but I chanced across one USB/serial adapter that goes down to 
75 bps.
which fortuitously was just what I needed at the time for the model 28 teletype 
(with the appropriate gears) I was attempting to drive.

The 75 wasn't readily accessible, I had to go to a low level in the unix config 
code and try sequential factors in the
configuration for the rate, 75 being another factor of 2 down in the standard 
rate series 19,200 . . 9600 . . 1200 . . 300 . . 150 . . 

Re: SWTPC 6800

[Fred Cisin]

On Tue, 9 Aug 2016, Brad H wrote:
I have a question though.. there have been a few times where I thought 
the 6800 crashed but may not have.  In several cases.. I sent a large 
loader file across and noticed errors coming through.. so I'd stop the 
machine.  This was after teraterm said it had sent everything through. 
 Is it possible the serial port on my PC is still trying to send out 
garbage for a while, messing up my connection to the 6800 until it 
finishes?  I kept moving cards around but eventually it seemed to start 
working after so many powerups and time had passed..


Do have any ACTUAL handshaking in the connection, or is it all bypassed to 
"go ahead, everything is ready, just send!"


If there is no FUNCTIONING handshake, then it could easily be as simple as 
the sender sending next byte before the receiver is ready for it.


Try adding another stop bit to the terminal software.



Sent from my Samsung device

 Original message 
From: Brent Hilpert  
Date: 2016-08-09  9:49 AM  (GMT-08:00) 
To: "General Discussion: On-Topic and Off-Topic Posts"  
Subject: Re: SWTPC 6800


On 2016-Aug-09, at 6:47 AM, Ethan Dicks wrote:

On Fri, Aug 5, 2016 at 6:55 PM, Chuck Guzis  wrote:

On 08/05/2016 02:15 PM, Brad H wrote:

I have one more question for you guys -- I have a few CT-1024
terminals and would really like this system to work with one of
those.  However, all of the CTs are quite delicate and are set I
think for 7, E, 2 @ 110 baud via soldered jumpers.


Well, 110 bps is a bit on the slow side--great for teletypes, not so
much for video terminals.


And I am not aware of any USB serial adapters that do 110 bps.  If
anyone knows of any, post brand and model numbers.


It didn't do 110, but I chanced across one USB/serial adapter that goes down to 
75 bps.
which fortuitously was just what I needed at the time for the model 28 teletype 
(with the appropriate gears) I was attempting to drive.

The 75 wasn't readily accessible, I had to go to a low level in the unix config 
code and try sequential factors in the
configuration for the rate, 75 being another factor of 2 down in the standard 
rate series 19,200 . . 9600 . . 1200 . . 300 . . 150 . .

--
Fred Cisin  ci...@xenosoft.com
XenoSofthttp://www.xenosoft.com
PO Box 1236 (510) 234-3397
Berkeley, CA 94701-1236

RE: SWTPC 6800

[Bill Sudbrink]

Ethan Dicks wrote:
> And I am not aware of any USB serial adapters that do 110 bps.
> If anyone knows of any, post brand and model numbers.

Well, I know of a few "vintage" ones, and seeing that this is
"Classic computer talk"...

I use Belkin F5U103 USB serial ports.  I got a stack of them at
a hamfest a few years back.  They work fine under at 110 bps under
Windblows XP.  I've never tried them under newer versions or under
linux.  I also use an old Annex terminal server that I seem to
remember will do 110 but I've had it all set for 9600 for a long
time.

Bill S.

Re: the value of old test and repair equipment

[Joseph Zatarski]

>I really like my old test gear and yes, it just seems right to be restoring
>vintage computers with vintage instruments.  HP scopes, logic analyzers,
>DVMs; function generator; Tek scope, frequency counter; as well as just
>'sundry'.  But I did break down and buy a DDS frequency generator to work
>on my VHF/UHF ham gear.
>
>On Sat, Jul 30, 2016 at 6:07 PM, drlegendre . > wrote:
>
>>* In fact, the value of old test gear varies tremendously..
** Vacuum tube testers of certain makes & models are near the top
of the food
*>>* chain, with clean, working examples pulling $1500+ (USD) on a very regular
*>>* basis.
** There's also a strong following for much 'classic' audio
analysis gear (HD
*>>* meters, ID meters, spectrum analyzers, etc.) some very fine multi-meters
*>>* and anything really hi-end like General Radio, Breull & Kejjr, HP, and so
*>>* forth.
** Some very early examples from the 1910s to 30's also pull good
value simply
*>>* for visual appeal. Much of this gear is resplendent with embossed, enameled
*>>* panels, sculpted Bakelite knobs, large meter movements and an overall Art
*>>* Deco styling.
** Seen a nice Supreme Diagnometer recently? Or any of the 40s-70s
era English
*>>* made tube testers, like the AVO? Hickok also made a series of bench VTVMs
*>>* with massive chromed meters, designed to be large enough that they can be
*>>* read from many feet away.. those are beautiful for display, and guess what
*>>* - they work great, too!
** On Thu, Jul 28, 2016 at 5:24 PM, Dale H. Cook http://www.classiccmp.org/mailman/listinfo/cctalk>> wrote:
** > At 03:52 PM 7/28/2016, Electronics Plus wrote:
*>>* >
*>>* > >... does as-is old test and repair equip that won't be particularly
*>>* cheap
*>>* > have interest to you guys?
*>>* >
*>>* > It depends entirely on the make and model of equipment. I always have a
*>>* > laundry list of stuff I am looking for - one of the reasons why I bring
*>>* my
*>>* > tablet to meets.
*>>* >
*>>* > Dale H. Cook, GR / HP Collector, Roanoke/Lynchburg, VA
*>>* > http://plymouthcolony.net/starcity/radios/index.html

*>>* >
*>>* >
*>>>
>
>
>--
>Ian S. King, MSIS, MSCS, Ph.D. Candidate
>The Information School 
>Dissertation: "Why the Conversation Mattered: Constructing a Sociotechnical
>Narrative Through a Design Lens
>
>Archivist, Voices From the Rwanda Tribunal 
>Value Sensitive Design Research Lab 
>
>University of Washington
>
>There is an old Vulcan saying: "Only Nixon could go to China."


All this talk of older test equipment reminds me of the HP 4261A LCR
bridge I repaired a while back, last winter I think.


My dad found the 4261A in the garbage years ago, and it seemed to work
fine, until one day he powered it up and the display showed garbage.
He decided to open it up, and noticed some uncovered windowed EPROMs.
Knowing that EPROMs sometimes flip bits in their old age, we decided
that was the first place we would look. We were also able to locate
the full HP service manual in PDF form for the instrument which helped
tremendously. In typical HP fashion, it had full theory of operation,
schematics, state diagrams, etc.


Now, I have an EPROM burner that does your typical JEDEC pinout parts,
27 series and such. The issue is that these were Intel i1702A's from
the early 70's I think. Not only are 1702's a totally different
pinout, but they run on 14V (a +5V, and a -9V rail, with no connected
ground, this is how intel got TTL levels on a MOS chip at the time).
The 4261A has a total of 4 1702's, two of which form a finite state
machine which controls the instrument, while the other two perform
display decoding.


I had to pull out my dad's DeVry Console 80, which has adjustable
positive and negative supplies, and I manually clocked out the data
and compared the contents to a dump I found online. I started with the
state machine EPROMs, and compared the data. I did find a few
discrepancies, but there was too much difference to have been bit rot.
Given the sudden nature of the issue, I would have expected one, at
most a couple bit flips, or something much more drastic (like total
chip failure). Upon reading through the state diagrams in the HP
manual, I noticed that there was a change noted in the state diagram
between certain minor revisions of the 4261A. I looked at what the
changes were, and deduced that my ROMs were in fact correct for the
serial number prefix.


At a dead end with the EPROMs, I decided to see if the state machine
was even running at all. I used a DVM in DC mode, and measured perfect
TTL ones and zeroes on all the state number outputs, which means those
outputs weren't changing: the state machine was stuck. I wrote down
the state it was stuck in and referred to the state diagram. I noticed
something interesting. The state machine in the 4261A is able to
evalu

Re: VCFMW 11 Updates and Special Guest

[Jörg Hoppe]

Jason,

Update to the exhibition "Jack Rubin/Joerg Hoppe/Mark Matlock - Digital 
PDP-8 minicomputers and a preview of the PiDP-11 "

I'm also showing an original PDP-15 panel with SimH simulation behind.
See 
http://retrocmp.com/projects/blinkenbone/blinkenbone-physical-panels/256-pdp-15-console-panel-on-blinkenbone


best regards,
Joerg

Am 08.08.2016 um 23:49 schrieb Jason T:

Hello retro fans - we are approaching the one month point before the
Eleventh Vintage Computer Festival Midwest and plans are quickly
coming together.  Here are a few announcements and updates to bring
you up to speed:

- We're happy to announce our very special guest speaker, former
Commodore engineer, Bil Herd!  Bil will deliver an entertaining
90-minute talk and Q&A on his time at Commodore and his many
post-Commodore adventures in engineering that continue today.

- We are going to be packed FULL!  And that means full of great
exhibits, including the ones listed here:  http://vcfmw.org/ex.html.
The main hall's tables are all accounted for but there will be some
unassigned space in one of the side rooms for late-comers and
impromptu displays.

- VCFMW Auction - an experiment last year, now a feature!  Quality
entertainment and a fundraiser for the show, 4pm Saturday will see
another auction of donated items at low starting bids.  If you have
items you wish to donate for auction, please get in touch with show
organizers Friday night or early Saturday.  Auctions items need not be
classic computing related.  No registration is required for the
auction.

- The Free Pile tradition continues!  One corner of the "Grove" side
room (http://vcfmw.org/HIEGV_FloorplanDetail.jpg) will be dedicated to
the infamous Free Pile - leave your junk there but be prepared to take
it home if it's still there Sunday afternoon!  No printers, please!

- Hotel rooms are still available at the $84/night convention rate;
please follow the link at http://vcfmw.org or use the code "VCF" when
calling the hotel; if you are unable to obtain the con rate, please
let me know as I may have to ask the hotel to expand the reservation
block.

- We remind you that VCF Midwest is a community-funded show; we
receive no funding from any other organization.  If you appreciate
what we do and you are able, please visit the donation links on our
site at http://vcfmw.org.

Please feel free to help us get the word out and re-post this message
in your favorite vintage-related forum.  Thank you for your interest
and support and we'll see you in September!

-j

Re: VCFMW 11 Updates and Special Guest

[Jason T]

On Tue, Aug 9, 2016 at 2:56 PM, Jörg Hoppe  wrote:
> Jason,
>
> Update to the exhibition "Jack Rubin/Joerg Hoppe/Mark Matlock - Digital
> PDP-8 minicomputers and a preview of the PiDP-11 "
> I'm also showing an original PDP-15 panel with SimH simulation behind.
> See
> http://retrocmp.com/projects/blinkenbone/blinkenbone-physical-panels/256-pdp-15-console-panel-on-blinkenbone

Very cool project!  We're going to be honored to have it at our show.
I've updated the site with the new info and link.

-j

Re: the value of old test and repair equipment

[Eric Smith]

On Sat, Aug 6, 2016 at 11:56 PM, tony duell  wrote:
> Since a Bell modem would cause a lot of problems on an old
> UK phone line,

Why is that? Are the electrical characteristics of the phone line
actually that different from US lines?

I worked for a modem company for a few years, though I mostly was
involved with IP routers. I know homologating our modems for use in
other countries was always a giant pain, but the problems were almost
entirely regulatory hurdles, and not so much that the modem wouldn't
actually work.

Photo album and video from VCF West

[jim stephens]

https://goo.gl/photos/KdnDMBHeryMZqctV9

Youtube Channel playlist of videos.

Some walking around Saturday morning before the show, Charles Anthony's 
exhibit.


Also a fellow who dropped by after my buying a PDP 11/34 and was one of 
the engineers.


I recorded an impromptu interview with him.

https://www.youtube.com/watch?v=UtmVGeVhr7A&list=PL5NK70kdq3-JGwb_8GXFN5SqDtbTKtLi7

Sherman Foy and I had a great time attending and participating in the 
event this year.


Thanks to the organizers, staff and volunteers that were there to put it on.

Thanks
Jim

Re: Photo album and video from VCF West

[Rod Smallwood]

On 10/08/2016 00:37, jim stephens wrote:


https://goo.gl/photos/KdnDMBHeryMZqctV9

Youtube Channel playlist of videos.

Some walking around Saturday morning before the show, Charles 
Anthony's exhibit.


Also a fellow who dropped by after my buying a PDP 11/34 and was one 
of the engineers.


I recorded an impromptu interview with him.

https://www.youtube.com/watch?v=UtmVGeVhr7A&list=PL5NK70kdq3-JGwb_8GXFN5SqDtbTKtLi7 



Sherman Foy and I had a great time attending and participating in the 
event this year.


Thanks to the organizers, staff and volunteers that were there to put 
it on.


Thanks
Jim

Hi Guys
Now that is a very interesting set of Photos.  Loads of 
what appear to be real front panels complete with bezels.
As you know I produce reproduction panels and seeing all of those was 
most interesting.

I have the process to make the actual panels just about right.

So to bezels. I have made one prototype resin cast PDP-8  bezel. There 
are a  few things to fix but essentially its OK.
The next example should good enough to paint. Attach it to the panel and 
we have something like a full size front.


Next up is a  Key and Lamp board. I have a sample for an 8/i  lamp board.
Its new and not wanting to reinvent the wheel  I'll use it with the 8/i 
now in production
Lever and butterfly toggle switches are the main difficulty at this 
point. But sooner or later somebody will figure out how to

make toggle switches at reasonable cost.

Having just about done all of the popular PDP-8's  Its PDP-11's next..

Rod (Panelman) Smallwood






Finally

Re: Photo album and video from VCF West

[jim stephens]

We had a discussion about your great work.  One comment mentioned more 
than once was that they can scratch because you did an exact job of how 
the originals were made.   And there may not be a coating today that 
doesn't crinkle or shrink on other plastics.  You would have to match 
pretty closely the clear overcoat, and basic clear panel to stop that, 
so they didn't react or shrink at different rates with age, and perhaps 
do some sort of processing with the stencil material to stop it from 
flaking off as well.  But they are still great from what everyone said.


I emailed you offline about one for Sherman as well
thanks
Jim

On 8/9/2016 6:30 PM, Rod Smallwood wrote:



On 10/08/2016 00:37, jim stephens wrote:


https://goo.gl/photos/KdnDMBHeryMZqctV9

Youtube Channel playlist of videos.

Some walking around Saturday morning before the show, Charles 
Anthony's exhibit.


Also a fellow who dropped by after my buying a PDP 11/34 and was one 
of the engineers.


I recorded an impromptu interview with him.

https://www.youtube.com/watch?v=UtmVGeVhr7A&list=PL5NK70kdq3-JGwb_8GXFN5SqDtbTKtLi7 



Sherman Foy and I had a great time attending and participating in the 
event this year.


Thanks to the organizers, staff and volunteers that were there to put 
it on.


Thanks
Jim

Hi Guys
Now that is a very interesting set of Photos. Loads of 
what appear to be real front panels complete with bezels.
As you know I produce reproduction panels and seeing all of those was 
most interesting.

I have the process to make the actual panels just about right.

So to bezels. I have made one prototype resin cast PDP-8  bezel. There 
are a  few things to fix but essentially its OK.
The next example should good enough to paint. Attach it to the panel 
and we have something like a full size front.


Next up is a  Key and Lamp board. I have a sample for an 8/i  lamp board.
Its new and not wanting to reinvent the wheel  I'll use it with the 
8/i now in production
Lever and butterfly toggle switches are the main difficulty at this 
point. But sooner or later somebody will figure out how to

make toggle switches at reasonable cost.

Having just about done all of the popular PDP-8's  Its PDP-11's next..

Rod (Panelman) Smallwood






Finally

RE: the value of old test and repair equipment

[tony duell]

> > Since a Bell modem would cause a lot of problems on an old
> > UK phone line,
> 
> Why is that? Are the electrical characteristics of the phone line
> actually that different from US lines?

Electrically the lines are almost identical (there are differences in things
like ringing voltage and frequency, but you can plug a US telephone
into a UK line with no technical problems).

The problem is that one of the 300 baud Bell tones is effectively the
same as (I think) the long-distance clearing signal. Something like that
anyway. If you connect your 300 baud US modem over here it will 
effectively cause the exchange to hang up.

Modems sold in the UK have/had to be incapable of sending the
Bell tones, for that reason. One famous one based on the AM7910
chip had a pin in the mode selector switch that prevented it being
set to the positions for the Bell tones. This pin could be removed 
without even opening the case. I did that to mine, as I use it on a line
simulator (not the public network) for testing US modems, etc.

-tony

Re: CCS S-100 system avail in Minneapolis

[william degnan]

All - I have forwarded to the donor of the California Computer System in MN
contact info of the first three who responded.   Good luck!
Bill

On Mon, Aug 8, 2016 at 9:33 PM, drlegendre .  wrote:

> mailed.
>
> On Mon, Aug 8, 2016 at 10:01 AM, william degnan 
> wrote:
>
> > I was contacted about a CCS S-100 system available for pickup in
> > the Minneapolis area.  Contact me privately.  Includes CP/M software,
> etc.
> > A full station wagon full of stuff/docs.  I don't know the guy, just
> trying
> > to help out.
> >
> > http://www.vintagecomputer.net/contact.cfm
> >
> > Bill
> >
>



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