seeking Motorola M68MM01A2 documentation

[Chris Elmquist via cctalk]

I have quite a few Motorola Microsystems Exorciser boards including this
6800 single board computer for which I am lacking any documentation.

I've seen a brochure in Al's collection on Bitsavers but haven't found
any details that might discuss jumper settings or even better,
a schematic.

Wondering if anyone would have a user manual or other detailed docs for
this board?

M68MM01A2 -- has 6800 CPU, 6875 1.0 MHz clock generator, 6850 ACIA and
MC14411 baud rate clock, (4) EPROM/ROM sockets and (2) 6821 PIA sockets
with the 86-pin Exorciser edge connector.

I'm interested in seeing if I can minimally modify it to have a similar
memory map to the Altair 680 so that the Altair's PROM monitor could
run on it.

Thanks!

Chris
-- 
Chris Elmquist

Re: seeking Motorola M68MM01A2 documentation

[Chris Elmquist via cctalk]

On Tuesday (01/18/2022 at 02:09PM -0500), Bill Degnan wrote:
> Not exactly a match but I do have this, if it helps:
> https://www.vintagecomputer.net/motorola/mek6800d2/MEK6800D2.pdf

Thanks Bill.  I have that too and in fact a couple D2 boards so
I am set there.

This is a specific detail so that I can make mods to the board without
having to reverse engineer it first.  But I suspect it will come to that.

Thanks anyway!

Chris

> On Tue, Jan 18, 2022 at 1:54 PM Chris Elmquist via cctalk <
> cctalk@classiccmp.org> wrote:
> 
> >
> > I have quite a few Motorola Microsystems Exorciser boards including this
> > 6800 single board computer for which I am lacking any documentation.
> >
> > I've seen a brochure in Al's collection on Bitsavers but haven't found
> > any details that might discuss jumper settings or even better,
> > a schematic.
> >
> > Wondering if anyone would have a user manual or other detailed docs for
> > this board?
> >
> > M68MM01A2 -- has 6800 CPU, 6875 1.0 MHz clock generator, 6850 ACIA and
> > MC14411 baud rate clock, (4) EPROM/ROM sockets and (2) 6821 PIA sockets
> > with the 86-pin Exorciser edge connector.
> >
> > I'm interested in seeing if I can minimally modify it to have a similar
> > memory map to the Altair 680 so that the Altair's PROM monitor could
> > run on it.
> >
> > Thanks!
> >
> > Chris
> > --
> > Chris Elmquist
> >
> >

-- 
Chris Elmquist

Re: seeking Motorola M68MM01A2 documentation

[Chris Elmquist via cctalk]

On Tuesday (01/18/2022 at 02:01PM -0600), Mike Katz wrote:
> I think it might be easier to modify the 680 prom for the I/O addresses of
> the board rather than modify the board to match the ROM.

Agreed-- except the goal, which I failed to elaborate on, is to come
up with an Altair 680 development environment so that someone can port
some code to the platform without having the real thing.  I wanted to
make that environment as close to real as possible (without having front
panel switches and LEDs)-- which means having the I/O in the same place
as the original as well as the authentic PROM code running.

> Especially if the address decoding for the I/O is done in PAL (10L8 for
> example).

No PALs on the board but there is a bipolar PROM (82S129). I'm not
adverse to making a new one of those or bodging something that drops
into that socket to modify the decoding if neccessary.  I was just hoping
to not have to butcher the board itself too much.

> Some 6800 address decoding was done with 74LS138s.  This had the potential
> to be inefficient in terms of memory usage or if the '138s were cascaded
> then propagation delay could become an issue.

Yes.  This seems to be a limited function CPU board and I suspect it takes
that approach just to get the four PROMs and I/O decoded very coarsely.

Chris
-- 
Chris Elmquist

Re: seeking Motorola M68MM01A2 documentation

[Chris Elmquist via cctalk]

On Tuesday (01/18/2022 at 03:37PM -0600), Mike Katz wrote:
> If the software is using ROM routines then the address doesn't matter for
> the applications.  If not, you can create an abstraction layer (set of
> drivers for the ACIA, 6875 Timer and PIA) and if all of the code is written
> to the abstraction layer then all you need to do is link in the appropriate
> binary for the abstraction layer. This will work for both C and machine
> language.

Understood but I don't want to force the developer to make different code
for this machine than for the real 680.  This is an attempt to get him
something that he can use to make code for the real 680 without having
a real 680.

I have a real 680 myself but I'm not up to shipping it around, loaning
it out, etc. yet still want to help the effort.  But since I am not the
one actually doing the effort, I wanted to help by providing something
that was usable without having to change his approach.

Thanks for the suggestions though.

Chris

> On 1/18/2022 2:14 PM, Chris Elmquist wrote:
> > On Tuesday (01/18/2022 at 02:01PM -0600), Mike Katz wrote:
> > > I think it might be easier to modify the 680 prom for the I/O addresses of
> > > the board rather than modify the board to match the ROM.
> > Agreed-- except the goal, which I failed to elaborate on, is to come
> > up with an Altair 680 development environment so that someone can port
> > some code to the platform without having the real thing.  I wanted to
> > make that environment as close to real as possible (without having front
> > panel switches and LEDs)-- which means having the I/O in the same place
> > as the original as well as the authentic PROM code running.
> > 
> > > Especially if the address decoding for the I/O is done in PAL (10L8 for
> > > example).
> > No PALs on the board but there is a bipolar PROM (82S129). I'm not
> > adverse to making a new one of those or bodging something that drops
> > into that socket to modify the decoding if neccessary.  I was just hoping
> > to not have to butcher the board itself too much.
> > 
> > > Some 6800 address decoding was done with 74LS138s.  This had the potential
> > > to be inefficient in terms of memory usage or if the '138s were cascaded
> > > then propagation delay could become an issue.
> > Yes.  This seems to be a limited function CPU board and I suspect it takes
> > that approach just to get the four PROMs and I/O decoded very coarsely.
> > 
> > Chris

-- 
Chris Elmquist

Re: seeking Motorola M68MM01A2 documentation

[Chris Elmquist via cctalk]

On Tuesday (01/18/2022 at 11:35PM +), Jonathan Chapman wrote:
> How's about a Glitchbus board set that's compatible? I was planning on doing 
> it anyway.

That would be very cool.  Something along those lines was my plan B and
I even dug out a tube of 6802's for the effort.  I think I could wire
up a prototype over a weekend.  MC6802 is a nice "cheat" as you don't
have to mess with the two-phase clock stuff.

What would be really slick is an SBC that has everything on it to be
either an Altair 680 or an SWTPC 6800 just by changing some jumpers,
switches, etc. and putting the correct ROM monitor on the board.

If there was a PROM, a 32K SRAM, an ACIA and a bonus PIA socket, along
with a small amount of glue logic, I think we could run the ROM monitor
for either system and a bunch of legacy code in 32K of RAM-- which would
have been a big system in the day.  The PIA would provide a fun GPIO
capability just for toggling bits to and from the real world.

The ACIA was the serial console device on the Altair and the later
MP-S on the SWTPC and so you would run SWTBUG on the SWTPC personality
to use that.  I don't see a need for MIKBUG compatibility here, since
that requires the bit-banged console via another PIA and odd external
timer chip.  Baud rate generator that can do 16x for 110, 300, 1200 and
9600 would be ideal.  I'd want 110 for a real Teletype, 300 for Kansas
City Standard tapes, 1200 for a DecWriter and 9600 so that I don't fall
asleep ;-)

When can I order one!  :-)

Thanks Jonathan,

Chris
-- 
Chris Elmquist

Re: seeking Motorola M68MM01A2 documentation

[Chris Elmquist via cctalk]

On Wednesday (01/19/2022 at 03:35PM +0100), Jos Dreesen via cctalk wrote:
> On 19.01.22 13:15, Jonathan Chapman via cctalk wrote:
> > That's a neat board! Where can I/we order one?
> 
> With me...
> 20 Eur for the set of 2 + shipping.
> 
> If you are in the US it is probably cheaper to order new ones locally.
> 
> Note that I never completed the documentation or wrote the code for the hex 
> keyboard.
> But it does run the Tektronix board-bucket BASIC via serial port !
> 
> Find more on ftp://ftp.dreesen.ch/TEK_BB

ah ha! that's what I was looking for.  Will check it out in detail.
I think I am "forum challenged" as all I could see at the original link
were renderings of the board.

Thanks Jos.  Maybe this will be the ticket...

Chris

-- 
Chris Elmquist

Re: seeking Motorola M68MM01A2 documentation

[Chris Elmquist via cctalk]

And just to close the loop on the original documentation request--
someone has come forward with the exact manual for the M68MM01A2 board
and I very much appreciate that.

He has a lot of Exorciser boards and manuals to scan so I will let him
step forward when he's ready for that.  But I do greatly appreciate
getting this manual.

I think Jos' TEK_BB SBC will be the winning solution and thanks to Jos
for sharing it and Jonathan for running with it.  This way many people can
run Altair 680 or SWTPC 6800 code on a small footprint development board.

Chris

On Wednesday (01/19/2022 at 01:25PM -0500), Todd Goodman via cctalk wrote:
> Excellent information Jonathan!
> 
> I generally carry the s100computers and many RetroBrew board and have
> ordered over 5000 boards from PCBCart.com
> 
> I'm not a board designer but if people have any questions about PCB Cart and
> the board ordering process, feel free to contact me privately.
> 
> Todd
> 
> On 1/19/2022 1:14 PM, Jonathan Chapman via cctalk wrote:
> > Mike,
> > 
> > We use PCB Cart for boards with hard gold edge contacts, like our DEC 
> > prototyping board, Apple II protoboard, XT-IDE, etc. They are the same 
> > Chinese board house used by s100computers.com and N8VEM/RetroBrew 
> > Computers. Results are pretty good for the price.
> > 
> > Expect to order 25 to make hard gold edge plating worthwhile. It'll pretty 
> > much double the price of the board, but PCB Cart does proper selective hard 
> > gold, not "heavy ENIG" (not a thing) or some other nonsense. A lot of the 
> > cheaper places will only plate "hard gold" over ENIG, which I assume means 
> > they don't actually have a selective process at all.
> > 
> > Make sure to specify an edge chamfer if it's a typical card edge connector, 
> > otherwise it'll be routed square and a little difficult to insert/you'll 
> > have to dress it down with a file.
> > 
> > If practical for the board, remove unused contacts from the edge connector. 
> > They charge per-contact as a way to guesstimate their gold costs.
> > 
> > Thanks,
> > Jonathan
> > 
> > ‐‐‐ Original Message ‐‐‐
> > 
> > On Wednesday, January 19th, 2022 at 12:05, Mike Katz via cctalk 
> >  wrote:
> > 
> > > Johnathan,
> > > 
> > > I saw you will be ordering boards pretty soon.
> > > 
> > > I need to order some boards for my PDP-8/E but I've never ordered boards
> > > 
> > > before.
> > > 
> > > What board house do you use? Have you ever specified gold fingers before?
> > > 
> > > Any advice would be greatly appreciated.
> > > 
> > > Thanks,
> > > 
> > > Mike
> > > 
> > > +1 (773) 414-1044
> > > 
> > > On 1/19/2022 9:49 AM, Jonathan Chapman via cctalk wrote:
> > > 
> > > > Chris,
> > > > 
> > > > I'm probably going to order some of these on my next circuit board 
> > > > order (this week or next), do you want a set of them? Seems they are of 
> > > > course "hacking required," which is fine by me :P
> > > > 
> > > > Thanks,
> > > > 
> > > > Jonathan
> > > > 
> > > > ‐‐‐ Original Message ‐‐‐
> > > > 
> > > > On Wednesday, January 19th, 2022 at 10:24, Chris Elmquist via cctalk 
> > > > cctalk@classiccmp.org wrote:
> > > > 
> > > > > On Wednesday (01/19/2022 at 03:35PM +0100), Jos Dreesen via cctalk 
> > > > > wrote:
> > > > > 
> > > > > > On 19.01.22 13:15, Jonathan Chapman via cctalk wrote:
> > > > > > 
> > > > > > > That's a neat board! Where can I/we order one?
> > > > > > > 
> > > > > > > With me...
> > > > > > 20 Eur for the set of 2 + shipping.
> > > > > > 
> > > > > > If you are in the US it is probably cheaper to order new ones 
> > > > > > locally.
> > > > > > 
> > > > > > Note that I never completed the documentation or wrote the code for 
> > > > > > the hex keyboard.
> > > > > > 
> > > > > > But it does run the Tektronix board-bucket BASIC via serial port !
> > > > > > 
> > > > > > Find more on ftp://ftp.dreesen.ch/TEK_BB
> > > > > > 
> > > > > > ah ha! that's what I was looking for. Will check it out in detail.
> > > > > I think I am "forum challenged" as all I could see at the original 
> > > > > link
> > > > > 
> > > > > were renderings of the board.
> > > > > 
> > > > > Thanks Jos. Maybe this will be the ticket...
> > > > > 
> > > > > Chris
> > > > > 
> > > > > Chris Elmquist

-- 
Chris Elmquist

Re: Origin of "partition" in storage devices

[Chris Elmquist via cctalk]

On Tuesday (02/01/2022 at 01:41PM -0500), Chris Zach via cctalk wrote:
> > Which came first CLV CDs, or CLV LaserDiscs?
> 
> Laserdiscs by far. Only the very first models played CAV only.
> 
> CAV is nice because you can freeze frame without a frame buffer.

Yes!  My dad did some of the first work on LaserDiscs-- built 3Ms plant
for making them in the late 70s.

As a result, we always had "samples" from the production line to watch
at home and numerous different players to check out.

CAV allowed you to freeze frame, step forward and back and never loose
frame sync.  You had a solid picture no matter whether it was playing,
stepping or paused.  But, you also got at most about 30 mins / side on
a disc and so a movie was 3 or 4 discs in length.

With CLV, you got more on the disc, about an hour per side or a whole
movie on one disc but you could not smoothly pause or step it.  Some
players would completely disallow it and some would display the torn
image with pieces from multiple adjacent frames.

CAV was used a lot for educational discs where the player was controlled
by a computer (in one case we had, a Sony CP/M machine) which combined
the interactive educational software on the computer with video content on
the disc.  The Sony computer had a genlock system in it so that it could
overlay computer graphics on the video signal from the disc player.

This was 1979 or 1980 if I remember correctly.

Chris
-- 
Chris Elmquist

DEC top-mount corporate cabinet

[Chris Elmquist via cctalk]

On Saturday (02/26/2022 at 03:21PM -0500), pbirkel--- via cctalk wrote:
> A top-mount corporate cabinet looks like this:
> http://www.cosam.org/images/pdp11-23/front2.jpg  The "DECDatasystem"
> front-bar in the photo is over the 1U strengthener that braces the upper
> portion of the rack ... since there is no brace at the top (as yours has).
> Your cabinet will work fine; in my experience RL02's are always tight and
> fiddly any place but the top-spot.

Is there a (hand-)book that describes the DEC cabinets and in particular this
"top-mount corporate cabinet"?  Is there a BA # for this cabinet?

I have an 11/34 in said cabinet but it is missing this 1U strengthener
although I do have the 1U front-bar.  I had to jigger a means to hold
the front-bar in place and have been unable to understand how it would
correctly attach to the rack and the strengthener, probably because I
don't have the strengthener!

Any part numbers or drawings that show this arrangement would be quite
helpful.

Thanks!

Chris
-- 
Chris Elmquist

Re: DEC top-mount corporate cabinet

[Chris Elmquist via cctalk]

Thanks very much Paul and others.  The overview you linked is very
helpful as I now have the actual model number for the rack that I have.

It is indeed the H9642-AD 40" "Top Loader" but it is missing whatever
cross piece goes behind the H9544 DA Bezel (#4) shown in the component
parts diagram.

My mystery is what that cross piece behind the bezel looks like, how
it attaches to the vertical rails of the rack on each side and then how
the bezel attaches to the cross piece.

The back of the bezel has a ribbed channel that looks like some kind of
bolts or other threaded or inserted fasteners were screwed or snapped
into this channel and those were attached to the cross piece somehow.
That's my missing link ...

I fabricated an aluminum bar cross piece and then used heavy duty
hook and loop-like fasteners to attach the bezel to this aluminum bar
but it's cheesy and loose.  I'd like to someday find the proper solution.

Chris

On Tuesday (03/01/2022 at 03:23AM -0500), pbir...@gmail.com wrote:
> Chris:
> 
> The traditional DEC racks/cabinets are either full-height ("standard" =
> H960) and part-height ("short" = H967) 19" racks.  These are welded steel
> frames built for computer-room type environments.  When DEC started selling
> into office environments (think data processing / business operations) they
> designed a new line of cabinetry that was intended to fit into an office
> where sight-lines are important and the desire was to look/work more like
> other types of office equipment.  The PDP-11/60 was I think an early example
> of the redesigned cabinets -- really a double-wide plus a bit, but of more
> modest height (roughly that of the H967).  After that you see single-width
> cabinets holding just 18U like the one that you have -- capable of holding a
> complete, but modest, system.  These newer-style cabinets/racks are riveted,
> rather than welded.  Emphasis was on style, cost-effectiveness, and RF
> shielding given the need to operate near other types of office equipment.
> 
> Here's a good overview:
> http://vtda.org/docs/computing/DEC/Catalogs/EA21388-75_CabinetAccessoriesSup
> pliesCatalog1981.pdf 
> 
> On the left side of page 8-of-16 you'll see a description of the 40" Medium
> Systems Series, including diagrams and pictures of the "top-loader"
> (H9642-AD) and "front-loader" (H9642-CA) designs.  There isn't any "mod-kit"
> to go from one to the other.  It would be possible to get a functional
> top-loader out of a front-loader with some metal reworking.  Basically,
> remove the lid and then (in effect) move the cross-pieces down 6U and add
> what amount to four gusset plates for lateral bracing.  In the H9642-AD
> photo you can see the plates on the rear cross-piece.  The front is similar,
> but sensitive to ensuring that the center 6U isn't significantly occluded;
> the front cross-piece may require some modification.  There are a few other
> changes but moving the cross-pieces down are the key.  Notice the H9544 CA
> Trim Kit, RL01/RL02 -- these are plastic pieces that bridge the gap between
> the HDD cover and the cabinet side-panels; nice to have but they're mostly
> there for style.
> 
> If you decide to attempt (or simply want to gauge the complexity of) a
> conversion I can see about getting some close-up photos of the various
> components and connections.  A conversion would not be a simple task.
> 
> While the brochure speaks of "purchase as component kits" and the table
> simply states "Basic Frame Kit", it's not the *same* frame kit for -AD and
> -CA, and I suspect that "kit" in this case was not an IKEA flat-box of parts
> but rather a factory-assembled frame to which one added other components as
> appropriate for the intended use.  These frames are _seriously_ riveted.
> Notice that H9542-AD is distinct from the H9542-CA "component kit".
> 
> (Note that the TU80 -- http://gunkies.org/w/images/5/52/Tu80.jpg -- is
> basically a H9642-AD "top-loader" with a hinged lid and special-purpose 13U
> front.)

-- 
Chris Elmquist

Re: While on the subject of cabinets...

[Chris Elmquist via cctalk]

On Tuesday (03/01/2022 at 04:36PM -0800), Marc Howard via cctech wrote:
> I've got a PDP 11/34 I've never opened up.  It's mounted in a H9642
> cabinet.  I can't get the bloody thing to extend on the chassis track
> slides.
> 
> Is there a catch or lock screw on this unit?

Mine (and we may be learning, is not be a proper configuration) does not
have any release or catch to allow the CPU to slide out.  I just grab it
and start pulling and it slides out--  although it does not slide easily.
That could be due to old, stiffened lubricant on the slides.

BUT! make sure you pull out the front foot at the bottom of the rack to keep
the whole rack from tipping forward if you do get the CPU to slide out.

The CPU is a heavy beast and the rack WILL tip forward once the CPU is
out far enough.

Chris
-- 
Chris Elmquist

Re: Rack Discussion Continued - Slide lubricant

[Chris Elmquist via cctalk]

On Wednesday (03/02/2022 at 12:05PM -0600), Mike Katz wrote:
> I have several difficult slides in my H960 rack.
> 
> What is the best lubricant for the slides?
> 
> I was wondering if graphite would work better than oil due to the fact that
> it won't pick up dirt and dust.

I have not done this yet on these particular slides but I think I would
clean them well with something that would remove the old lubricant--
maybe isopropyl alcohol or even WD-40 (as a cleaner, not a lubricant)
and then grease them with light, white lithium grease.

I have used such on other equipment slides with success.

Chris

> On 3/2/2022 10:45 AM, Chris Elmquist via cctalk wrote:
> > On Tuesday (03/01/2022 at 04:36PM -0800), Marc Howard via cctech wrote:
> > > I've got a PDP 11/34 I've never opened up.  It's mounted in a H9642
> > > cabinet.  I can't get the bloody thing to extend on the chassis track
> > > slides.
> > > 
> > > Is there a catch or lock screw on this unit?
> > Mine (and we may be learning, is not be a proper configuration) does not
> > have any release or catch to allow the CPU to slide out.  I just grab it
> > and start pulling and it slides out--  although it does not slide easily.
> > That could be due to old, stiffened lubricant on the slides.
> > 
> > BUT! make sure you pull out the front foot at the bottom of the rack to keep
> > the whole rack from tipping forward if you do get the CPU to slide out.
> > 
> > The CPU is a heavy beast and the rack WILL tip forward once the CPU is
> > out far enough.
> > 
> > Chris

-- 
Chris Elmquist

Re: ID UV erasable PROMS used on an IBM PC board?

[Chris Elmquist via cctalk]

On Monday (03/21/2022 at 09:17PM -0700), Glen Slick via cctalk wrote:
> On Mon, Mar 21, 2022 at 8:25 PM Chuck Guzis via cctalk
>  wrote:
> >
> > The PROMs are most likely house-labeled Intel commodity parts with
> > JEDEC-standard pinouts, so it should be fairly easy, using an EPROM
> > reader, to figure out if these are 8KB, 16KB, 32KB or 64KB devices.
> 
> Some device programmers can read the manufacturer and device ID codes
> from a device, if they are implemented. That would be another way to
> check for a Intel standard part.

[...]

> 
> Intel 27256 - 89h / 04h
> Intel 27C256 - 89h / 8Ch

[...]

Trying not to hijack the thread too much but I have an Intel D27C256-200
here in my TL866II+ programmer and it returns ID  89h / 8Dh.

The TL866+software actually fails to program it if the "Check Id"
feature is enabled as it complains about ID mismatch.  But if I disable
that, it programs correctly and works in-circuit without issue.

Without disabling the Id check, there would be no way to program an
Intel 27256 on this programmer since there are no other 256K-bit Intel
offerings in the menu-- so I am suspecious of the situation.

Any idea why some Intel 256K-bit PROMs are 89/8C and some are 89/8D??
 
Chris
-- 
Chris Elmquist

Re: ID UV erasable PROMS used on an IBM PC board?

[Chris Elmquist via cctalk]

On Tuesday (03/22/2022 at 12:20PM -0700), Glen Slick wrote:
> On Tue, Mar 22, 2022 at 11:56 AM Chris Elmquist  wrote:
> >
> > Trying not to hijack the thread too much but I have an Intel D27C256-200
> > here in my TL866II+ programmer and it returns ID  89h / 8Dh.
> >
> 
> http://www.bitsavers.org/components/intel/_dataBooks/1993_Intel_Memory_Products.pdf
> Page 5-78 (Page 1201 of the PDF)
> Table 1. Mode Selection
> Intelligent Identifier - Manufacturer 89H
> Intelligent Identifier - Device 8DH
> That is for the A27C256 "Automotive" rated version.
> 
> My BP Microsystems BP-1610 device programmer software doesn't have an
> entry for that one either.

Interesting.  Thanks Glen.  The part is clearly labeled as
"D27C256-200V10" so they must not have gotten around to changing the D
to an A :-)

But, that explains it.  Thanks for the digging.

Chris
-- 
Chris Elmquist

Re: ID UV erasable PROMS used on an IBM PC board?

[Chris Elmquist via cctalk]

On Tuesday (03/22/2022 at 08:09PM -0700), Glen Slick wrote:
> On Tue, Mar 22, 2022 at 12:25 PM Chris Elmquist  wrote:
> >
> > On Tuesday (03/22/2022 at 12:20PM -0700), Glen Slick wrote:
> > > On Tue, Mar 22, 2022 at 11:56 AM Chris Elmquist  wrote:
> > > >
> > > > Trying not to hijack the thread too much but I have an Intel D27C256-200
> > > > here in my TL866II+ programmer and it returns ID  89h / 8Dh.
> > > >
> > >
> > > http://www.bitsavers.org/components/intel/_dataBooks/1993_Intel_Memory_Products.pdf
> > > Page 5-78 (Page 1201 of the PDF)
> > > Table 1. Mode Selection
> > > Intelligent Identifier - Manufacturer 89H
> > > Intelligent Identifier - Device 8DH
> > > That is for the A27C256 "Automotive" rated version.
> > >
> > > My BP Microsystems BP-1610 device programmer software doesn't have an
> > > entry for that one either.
> >
> > Interesting.  Thanks Glen.  The part is clearly labeled as
> > "D27C256-200V10" so they must not have gotten around to changing the D
> > to an A :-)
> 
> (Flogging a dead horse here slightly)
> 
> Just took a look at a previous version of that Intel databook:
> http://www.bitsavers.org/components/intel/_dataBooks/1991_Intel_Memory_Products.pdf
> 
> Page 5-56 (Page 325 of the PDF) 27C256
> Table 1. Mode Selection
> Intelligent Identifier - Manufacturer 89H
> Intelligent Identifier - Device 8DH
> NOTES:
> 4. Programming equipment may also refer to this device as the 27C256A.
> Older devices may have device ID = 8CH
> 
> So apparently the Device ID change is not specific to the A27C256
> "Automotive" rated version, just that in the 1993 version of the
> databook where I first looked the only EPROMs listed are the
> "Automotive" ones.

More interesting.  If the programming algorithms remained the same then I
guess it is just an issue for the programming system--  when it auto-IDs,
it should display (and allow!) 27C256A instead of 27C256.

I guess the next question is whether the programming algorithms really
are the same between the 8CH and the 8DH variants??

My limited testing suggests they are at least compatible since my 8DH
appears to be working when programmed as an 8CH.

Chris
-- 
Chris Elmquist

Re: ID UV erasable PROMS used on an IBM PC board?

[Chris Elmquist via cctalk]

On Wednesday (03/23/2022 at 04:18PM +0100), Christian Corti via cctalk wrote:
> On Wed, 23 Mar 2022, Chris Elmquist wrote:
> > More interesting.  If the programming algorithms remained the same then I
> > guess it is just an issue for the programming system--  when it auto-IDs,
> > it should display (and allow!) 27C256A instead of 27C256.
> > 
> > I guess the next question is whether the programming algorithms really
> > are the same between the 8CH and the 8DH variants??
> > 
> > My limited testing suggests they are at least compatible since my 8DH
> > appears to be working when programmed as an 8CH.
> 
> I didn't even know that primitive EPROMs have device IDs...
> Without looking for a data book, how is the ID mechanism implemented?

Intel called it "Intelligent Identifier(tm) Mode".

 From page 5-43 of my 1991 Intel Memory Products book, for the 27256,

You put Vh (+12V) on address A9 and then,

with A0=0, you will read out the manufacturer ID
with A0=1, you will read out the device ID

Chris
-- 
Chris Elmquist

[cctalk] Re: Wang bar napkin story [WAS:RE: Re: "Revival" of a dedicated Micropolis webpage on internet]

[Chris Elmquist via cctalk]

https://www.foryourparty.com/cocktail-napkins

--
Chris Elmquist

> On Aug 21, 2022, at 4:45 PM, Fred Cisin via cctalk  
> wrote:
> 
> On Sun, 21 Aug 2022, Ali wrote:
>> You should just do it and add a teeny tiny disclaimer at the bottom 
>> regarding the veracity of the story. It would make for a great gag gift! Or 
>> if you want to get real fancy have a QR code that can be scanned on each 
>> napkin for a site with more detailed discussion of the events.
> 
> I used to know an elderly fellow who had a reasonably complete printshop at 
> his house.  He used to do embossed fancy invitations, envelopes, etc.
> But, he's dead.  So, I no longer already have a printer.
> 
> I don't even know whether personalized napkins are printed on existing 
> napkins, or printed as a folio and then folded.
> 
> There are some home methods, such as an oversized rubber stamp, etc.
> But, I think that it should be done professionally.
> Simplest artwork would be simply a small circle, a large oval, and a small 
> square at the edge.  But, a border around would be nice.
> 
> 
> I don't think that I will get around to doing it :-(
> 
> If somebody else wants to pick up the idea, I would appreciate it if you 
> would give me a good price to buy a dozen or so of them.
> 
> --
> Grumpy Ol' Fred ci...@xenosoft.com

[cctalk] Re: Minicomputer front panel.

[Chris Elmquist via cctalk]

Ya.  Thanks for the mention but it was before my time.  I was in 8th grade when 
I first met Lincoln.  That was 1976. We did tune clocks on a CY203 a few times 
but it wasn’t until ETA that I started doing real work ;-)

All cool stuff though and the stories were endless and awesome.

cje

--
Chris Elmquist

> On Sep 23, 2022, at 1:31 PM, Chuck Guzis via cctalk  
> wrote:
> 
> On 9/23/22 10:52, ben via cctalk wrote:
> 
>> Just how do the supercomputer do i/o for all that floating numbers.
>> Weather maps I can see for output, but what about all that Top Secret
>> number crunching.
> 
> Well, consider the 1969 STAR-100; although not well documented, had a
> 512-bit wide, error-checked I/O channel that ran at memory speed.  Neil
> had various schemes for it, including a 100K RPM head-per-track drum
> that ran in vacuo.  I recall him mentioning that the prototype lasted
> around a minute before the observation window was covered with the
> remnants of the drum surface.
> 
> Or consider the STAR SCROLL--a very wide tape that ran over a
> head-per-track drum.  I don't recall seeing that prototype; maybe it
> existed only in the mind.   But we had to mention both in our responses
> to RFQs.
> 
> This may be before Chris Elmquist's time, but he might also remember.
> Too bad that Neil's no longer with us; I suspect that he had lots of
> amazing stories.
> 
> --Chuck

[cctalk] Re: Age of Tape Formats?

[Chris Elmquist via cctalk]

> On Mar 8, 2023, at 4:18 PM, Chuck Guzis via cctalk  
> wrote:
> 
> On 3/8/23 13:53, Sellam Abraham via cctalk wrote:
>>> On Wed, Mar 8, 2023 at 1:39 PM Chuck Guzis via cctalk 
>>> 
>>> wrote:
>>> 
>>> On the subject of 1/2" open-reel tape, I note that the tapes initially
>>> used with the IBM 726 drive (1952) used a cellulose acetate base.  In
>>> 1956, a switch was made to Mylar.   That's unfortunate, since early
>>> existing  726 tapes have almost certainly rotted away due to vinegar
>>> syndrome.
>>> 
>> 
>> I have what appears to be a stainless steel UNIVAC tape.  It isn't
>> crumbling away into dust anytime soon.
>> 
> Heavy bugger,no?
> Nickel-plated Vicalloy (a type of phosphor-bronze).

Yes, heavy.  I have one too, from UNIVAC 1

Who can read them now?  ;-)

cje

[cctalk] Re: mainframe vs mini

[Chris Elmquist via cctalk]

We still have ice on the inside of the windows up here 😉

Nice of you guys to remember this history.  Some of the STAR designers and team 
are still around and kicking.  Just had lunch with four of them last Friday.

I learned too that as they migrated the design from STAR to 205 to ETA10, some 
of that “magic” in the logic design became black magic as they got stuff 
working, like stream instructions,  but didn’t know how or why :-)
Simulation said it shouldn’t work but reality said it did…

cje
--
Chris Elmquist

> On Mar 9, 2023, at 10:11 PM, Chuck Guzis via cctalk  
> wrote:
> 
> As to what a "station" looked like:
> 
> https://i.pinimg.com/originals/15/6d/fa/156dfa0a3b573b6ff9ca074d62fb19a9.jpg
> 
> Those things with CRT terminals on them are stations--they handle the
> various I/O tasks.  Basically, 16 bit minicomputers.
> 
> The photo might be the installation at CDC ADL, from the low ceiling and
> cramped space.   During the OPEC oil embargo, I made myself comfortable
> with a pillow borrowed from my room at the Ramada and a good book
> nestled between the SBUs.   It was probably the warmest place for miles.
>  The offices at ARHOPS, by contrast, had ice on the inside of the
> windows...
> 
> Back then, in Sunnyvale, you had three choices if you were doing OS
> development.  You could turn in your build materials to the STAR-1Bs at
> SVLOPS and hope that an all-night (the 1B ran at 1/100 the speed of the
> 100) session didn't end in a system crash.   You could finagle some CE
> time at Lawrence Livermore, which was far from a sure thing (one of the
> reasons for having a DOE "Q" clearance).  Or you could hop the "noon
> balloon" out of San Jose to the Twin Cities and use the STAR at ADL.  If
> it was wintertime, my department in Sunnyvale had a "community parka"
> for those unfortunates visiting the land of ice sports.
> 
> --Chuck

Re: Trip to CHM - Hotel/Restaurant Advice

[Chris Elmquist via cctalk]

Are there any swap meets / flea markets in the area on weekends anymore?

I will be there in a couple weeks with a free Friday and Saturday. With
Friday likely reserved for CHM, I'd track down a swap meet on Saturday
if such things still exist.

Chris NØJCF 


On Friday (03/31/2017 at 09:17PM -0500), Sam O'nella via cctalk wrote:
> I thought the Vintage Computer festival west link might have recommended 
> hotels but I couldn't find anything for you.
> I did a similar trip but needed to be quite a few hours south for my actual 
> destination. I didn't find a very cheap hotel either, and the under $100 one 
> I did find near long Beach was quite underwhelming. The type my wife wouldn't 
> have let us stay at.
> What I did find more useful was a super small rental car for $98 that did 
> give me much more freedom to get around a few sites (and Weird Stuff).  It 
> was highly recommended not to sleep in the car though so best luck.
> I explored airbnb but it seems to mirror closely to hotel prices and a 
> surprisingly large amount want a 2 day stay.
> But CHM is definitely a fun trip. I have a quite large collection for home 
> computing so I wasn't sure how long I'd stay occupied but between the demos 
> and tours and just perusing I definitely could have enjoyed more than the 
> afternoon I spent.
> Best recommendations were ubering or rental car then get a hotel in your 
> price range but don't worry as much about location. Or get one near the train.
> 

-- 
Chris Elmquist

Re: Supercomputers, fishing for information

[Chris Elmquist via cctalk]

On April 3, 2017 1:18:31 PM CDT, Chuck Guzis via cctalk  
wrote:
>On Mon, Apr 3, 2017 at 9:37 AM, AJ Palmgren via cctech <
>cct...@classiccmp.org> wrote:
>
>> Hi, Plamen & Al,
>> 
>> I'm just catching up on some of these past threads involving QIC 
>> cartridges.  What ever became of these Paragon tapes?  Were you able
>> to read them and archive the contents?
>
>
>I'm probably showing my age (again), but "QIC" and "Supercomputers"
>just
>seems to be about as related as "Chateau Margaux" and "Cheez Whiz".
>
>If one is spending millions on a supercomputer, why would anyone want
>to
>put software for it on a QIC cart?
>
>
>--Chuck

The OS for the ETA -10 was installed from QIC tape because you put it in 
through an Apollo DN3000 or similar service unit...  pretty sure that was THE 
way to get 'er done on that machine.

Chris

-- 
Chris Elmquist

Re: Silent 700 thermal paper

[Chris Elmquist via cctalk]

On April 15, 2017 8:23:18 PM CDT, Paul Berger via cctalk 
 wrote:
>It would not hurt it to try, at worst the printout would be faint, how 
>well the paper survives depends a lot on how it was stored.  Direct 
>sunlight definitely will degrade the paper that is why it is often in 
>black bags.  If the paper is 8.5" wide you could use the roll paper for
>
>thermal fax machines, that paper should be readily available at office 
>supply stores.
>
>Paul.
>
>
>On 2017-04-15 10:05 PM, Charles Dickman via cctalk wrote:
>> How long does it last?
>>
>> I have two Silent 700 terminals that have not been used since the
>> mid-80's and a box of thermal paper. Is the thermal paper any good or
>> should I get some more before I try to play with the terminals.
>>
>> Is paper that wide available new and not NOS? I bought some TTY paper
>> and it was NOS and so it is just about to disintegrate before I use
>> it.
>>
>> -chuck

I have used new thermal FAX paper purchased at Staples within the last two 
years in both Silent 700 model 725 (first generation) and model 745 (second 
gen) terminals with great success.

I've found that even if the old paper hasn't darkened due to sunlight or more 
significantly, heat, age makes it brittle and so I decided not to risk it being 
too stiff or abrasive and damaging the print head. YMMV.

Chris N0JCF

-- 
Chris Elmquist

Re: Model M case screws

[Chris Elmquist via cctalk]

On Sunday (07/02/2017 at 10:22AM -0400), Paul Koning via cctalk wrote:
> 
> > On Jul 2, 2017, at 2:03 AM, Chuck Guzis via cctalk  
> > wrote:
> > 
> > On 07/01/2017 10:27 PM, Tony Duell via cctalk wrote:
> > 
> >> I was told years ago that in general the thinner-wall sockets are better
> >> quality -- they have to be made from stronger steel alloy to work at
> >> all. Obviously there are exceptions
> > 
> > It wouldn't surprise me if some of the cheaper stuff was made from pot
> > metal.  I encountered a small Chinese adjustable wrench that was, in
> > fact, made just that way with a nice chromium plating.  I think it was
> > intended to be more decorative than functional.
> 
> Something equally flimsy, yes.  I have a set of 100 "security" bits, $10 or 
> so from Harbor Freight.  I already chipped the phillips bit on a somewhat 
> tight screw.  For the price the stuff is ok, and definitely handy when 
> dealing with various oddball screws, but for anything that matters I go for 
> real tools.

I'm a little late to this thread but I didn't see anyone mention the Wiha
brand which also have a slim Nut Driver set with a 7/32" bit in the kit.
When I was refurbing a couple model M here, I invested in this Wiha set,

https://www.wihatools.com/tech-tools/precision-screwdrivers/precision-inch-nut-driver-8-piece-set

Easily found on Amazon but not in any local store around here...  especially
not Menards ;-)

Chris
-- 
Chris Elmquist

Stearns Computer

[Chris Elmquist via cctalk]

On Monday (08/14/2017 at 08:16AM -0600), Doug Ingraham via cctalk wrote:
> On Fri, Aug 11, 2017 at 5:14 PM, Chuck Guzis via cctalk <
> cctalk@classiccmp.org> wrote:
> 
> >
> > Was Warren Stearns connected with Stearns Computer Systems, maker of the
> > short-lived Stearns PC?
> >
> > --Chuck
> >
> 
> No, he wasn't.

Stearns Computer was here in Minneapolis (Minnetonka actually) and was
started by a bunch of former CPT guys.   I'm not sure I ever heard any
history of the name but it may have ties to Stearns County which is
just to the NW of the Cities or it might have something to do with
Stearns life jackets which all the fisherman around here wear.

I believe I am the only non-Stearns Computer employee to hold a full
certification for field repair of the Stearns PC.  I got this training
because at ETA Systems, we had over 200 of these PC-like machines and
were Stearns Computer's largest customer.  Some believe we were their
only customer.

I still have the certificate but no, I will not fix your Stearns
now :-)

Chris
-- 
Chris Elmquist

Re: Stearns Computer

[Chris Elmquist via cctalk]

On Monday (08/14/2017 at 01:16PM -0700), Chuck Guzis via cctalk wrote:
> 
> Yes, I recall that Neil tried to sell us on Stearns, but we elected to
> go with the pack and use IBM.  Good move that, in retrospect.

For sure.  The Stearns was (deliberately) not a very good IBM PC clone--
using a true 8086, a Eurocard backplane connector and a custom BIOS that
only allowed MSDOS (and not PC DOS) to run.  The video was different...
everything was different enough that all we did was hack just about
every app that people wanted to run so that it would limp on the Stearns.

Neil's goal at ETA (cc 1983) was to have a "paperless operation" and
every engineer, every manager, every secretary (that's what we called
them then) was to have a personal computer.  Most of the people had never
used a computer before and so we had to teach them what to do with them.

However, it was amazing to watch and didn't take too long before they
were all wanting REAL IBM PC stuff-- because they saw it on TV, in the
magazines, everywhere-- and sadly, the Stearns really could not deliver.

At the time CDC (and ETA by proxy) also had a group purchase deal with
Zenith and so we began to see the Z100 (again not a PC but well supported
software-wise) and finally the Z150 displace the Stearns as something
you could really get work done with.

As _the_ Stearns support guy, I had a Z100 :-)

Chris
-- 
Chris Elmquist

Re: RIP Jerry Pournelle, the first author to write a novel on a computer Early adopt

[Chris Elmquist via cctalk]

Lincoln had ETAOIN on his personalized MN license plate (on the very well worn 
Ford full size van he drove) and another guy had SHRDLU on his plates.

I was told that the name came from this string which could be found in printed 
works and that people had always seen it but just read past it because it 
didn't fit or make sense.  I believe it was Neil's youngest son Brian who 
offered up this name but I'm not remembering why anymore.

There was also a Lincoln story that ETA was like The Eta, a Spanish terrorist 
group and all of us at ETA were going to terrorize the supercomputer industry.

Chris

On September 10, 2017 9:55:02 PM CDT, Chuck Guzis via cctalk 
 wrote:
>On 09/10/2017 06:25 PM, Tapley, Mark via cctalk wrote:
>
>> There was one of those machines in my Junior High School shop
>> classroom. I saw it run once (not well enough to successfully set a
>> line of type, but nearly).
>> 
>> I endorse Mark’s assessment of its safety characteristics...
>
>I knew a fellow who had one of them in his barn--and he set the local
>freebie weekly newspaper with it.   Open gas flame, hot type metal
>that's mostly lead, lots of open whirling parts--what's not to like?
>
>Running one is definitely a real skill.  ETAOIN SHRDLU CMFWYP...
>
>Neil Lincoln once told me that the name of ETA Systems back in the 80s
>was suggested by his son.  Neil knew about the Linotype order, but it
>was unclear to me if his son got it from a literary work (there were
>several) or from the actual machine.  Chris Elmquist might know.
>
>FWIW, the "assembler" in a Linotype machine is where the type matrices
>drop down in a row, ready for "kerning".  Another non-computer use of
>the word.
>
>--Chuck

-- 
Chris Elmquist

Re: ETAOIN SHRDLU (Was: RIP Jerry Pournelle, the first author to write a

[Chris Elmquist via cctalk]

On Monday (09/11/2017 at 08:57PM -0700), Chuck Guzis via cctalk wrote:
> On 09/11/2017 08:35 PM, Fred Cisin via cctalk wrote:
> > Etaoin Shrdlu was most importantly one of Walt Kelly's characters in Pogo.
> > 
> > ETAOIN SHRDLU   ETA name
> > On Mon, 11 Sep 2017, Chris Elmquist via cctalk wrote:
> >> I was told that the name came from this string which could be found in
> >> printed works and that people had always seen it but just read past it
> >> because it didn't fit or make sense.
> > 
> > That is canonically "loren ipsum", the filler "greeking" text used to
> > set up layout.
> > Although admittedly ETAOIN SHRDLU was also sometimes used for greeking.
> 
> It also inadvertently crept into printed copy.  If the Linotype operator
> made an error in a line, it was common to just fill the line out with
> ETAOIN SHRDLU so that the copy editor would know to discard the line.

Yes-- this was the basis of Lincoln's ETA story that the string appears
in printed works because some editor missed it and didn't take it out.

Chris
-- 
Chris Elmquist

Re: A Mystery

[Chris Elmquist via cctalk]

Same kid that put oatmeal in the VCR?

https://youtu.be/25abPjKr06U


On October 10, 2017 8:07:47 AM CDT, Rod Smallwood via cctalk 
 wrote:
>I have in my possession a back plane from a BA23.
>
>Somebody has put glue in the last three slots.
>
>Can anybody explain that?
>
>Rod

-- 
Chris Elmquist

Re: Halt and Catch Fire (TV series)

[Chris Elmquist via cctalk]

I saw a credit flash by at the end of the final episode with a name I
recognized,

Carl Ledbetter
Technical Consultant

Turns out, it _is_ the Carl LedBetter who headed up ETA for a while,

https://www.forbes.com/sites/cherylsnappconner/2014/05/29/lessons-in-tech-and-business-amcs-new-halt-and-catch-fire/#4d8261652339

http://pelionvp.com/team/carl-ledbetter/

-- 
Chris Elmquist

Re: Look to get a copy of a Multi-Tech FM300 Modem manual

[Chris Elmquist via cctalk]

Give me a day or two and I think I can help you out.  I used to work at 
Multi-Tech when the FM300 was still a product.  I have several along with 
original schematics, which are "blue prints"...

I have almost as many stories about Multi-Tech as I do ETA ;-)

Chris

On October 29, 2017 1:40:03 PM CDT, Pete Lancashire via cctalk 
 wrote:
>I've acquired a Multi-Tech FM300 acoustic modem and even though I could
>figure out the pin-outs
>and switch settings, it would be great if I could get a copy of the
>original manual.
>
>Goal is to add it to a Teletype 33 or 35 and a Bell System 500 desk
>set.
>
>-pete

-- 
Chris Elmquist

Looking for Silent 700 model 787 manual

[Chris Elmquist via cctalk]

I recently acquired a TI Silent 700 model 787 terminal.  This cc 1980
unit is an interesting member of the Silent 700 family as it is capable
of 120 chars/sec printing and has an internal 300/1200 baud direct connect
modem that does Bell 103, Bell 212A and Vadic modulation in both originate
and answer modes.

It's a got a DB25 on the back for directly connecting serial but I don't
have any documentation on how to choose the internal modem vs the DB25
for comms or any pinouts for this DB25 outside the usual expectations
of RS232 on a DB25.

Seeking any documentation that might be around.  Happy to cover copying
costs or purchase a manual if it is excess to someone's needs.

Chris
-- 
Chris Elmquist

Re: Looking for Silent 700 model 787 manual

[Chris Elmquist via cctalk]

On Sunday (11/19/2017 at 05:46PM -0800), Fred Cisin via cctalk wrote:
> On Sun, 19 Nov 2017, Chris Elmquist via cctalk wrote:
> >I recently acquired a TI Silent 700 model 787 terminal.  This cc 1980
> >unit is an interesting member of the Silent 700 family as it is capable
> >of 120 chars/sec printing and has an internal 300/1200 baud direct connect
> >modem that does Bell 103, Bell 212A and Vadic modulation in both originate
> >and answer modes.
> >It's a got a DB25 on the back for directly connecting serial but I don't
> >have any documentation on how to choose the internal modem vs the DB25
> >for comms or any pinouts for this DB25 outside the usual expectations
> >of RS232 on a DB25.
> 
> Some models of Silent 700 had a connector (I seem to remember it as maybe
> being DA-15?, instead of DB-25?) that permitted it to connect to external
> modem, AND permitted external devices to connect to the Silent 700 internal
> modem, or a loop back (defaulted to jumpered to that internally)
> ofconnecting the terminal to its modem.

Yes indeed.  I have several of those, model 745 as one example, and it
is a DA15 for which I have the pinout and made a cable for hooking to
various old micros here.

This 787 is a later generation with some noticable differences in the
connectoring, switches, LEDs, etc.   It is for sure a DB25 female and
below that, behind a flip-up cover, is an RJ11/13 (six pin) telephone
jack for the modem.

The unit is also taller/thicker than the 745 generation.  It's roughly
another inch thick with the extra bulk on the bottom.  At first I thought
it might be a model with bubble memory but it is not.  Instead, it's the
"go faster" model with 120cps rather than 30cps printing.

There is a flip-card instruction manual inside the paper door which does
reveal some keyboard commands to change the baud rate (up to 9600 bps)
and the modem modulation and answer vs originate but there are no clues
about how to select modem or serial port or other more hardware specific
things.

Will be on the hunt for a service manual now.  I have such for both my
1st (model 725) and 2nd (model 745) generation units so might as well
get one for this beast too.

Chris
-- 
Chris Elmquist

Re: Looking for Silent 700 model 787 manual

[Chris Elmquist via cctalk]

On Monday (11/20/2017 at 09:40AM -0600), Jason T via cctalk wrote:
> On Sun, Nov 19, 2017 at 9:18 PM, Chris Elmquist via cctalk
>  wrote:
> > Yes indeed.  I have several of those, model 745 as one example, and it
> > is a DA15 for which I have the pinout and made a cable for hooking to
> > various old micros here.
> 
> Is that posted/can you post that cable pinout somewhere?  I've got a
> number of those models and have never been able to attach anything to
> those ports.

Hey Jason--

It's here, (Thank You Al)

http://www.bitsavers.org/pdf/ti/terminal/silent_700/984025-9701rC_743_KSR_745_Portable_Maintenance_Manual_Jul78.pdf

page 2-3, table 2-1  (pdf page 13).

I think the terminal is normally supplied with a "loopback" plug
(that's almost always missing) that goes into that DA15-M and loops the
"printer/keyboard interface" to the "communications interface" when you
are using the onboard acoustic coupler.  If you want to talk to a local
host not over the modem, then you remove that loopback plug and plug in
your own cable that goes to your host.

I made this cable with DA-15 female on one end and DE9-male on the other
so that this terminal would look like a PC serial port and connect to
various DCEs such as a terminal server and other stuff I have here wired
for direct connect to a PC comm port,

DA15-F  DE9-M

1   5   GND
11  1   CD
12  2   RXD (to the terminal)
13  3   TXD (from the terminal)
15  4   DTR


Keep on the lookout for a model 787 manual.  This thing is cleaning up
quite nicely and I hope to put the juice to it later today or tomorrow.
It was found on the floor of a garage-- that would be the dirt floor.
Not cool and it looked pretty rough on the outside but hoping it's still
happy on the inside ;-)

Chris 
-- 
Chris Elmquist

Re: RL02 to PC image

[Chris Elmquist via cctalk]

I thought about doing this with an FTDI FT245, which is a parallel to USB FIFO 
device that looks like a USB serial port to the USB-side host.  USB protocol 
will manage all the “flow control” and so the PDP can write to it as fast as it 
can.

We did a similar thing on Heathkit H89 and H8 machines, replacing an 8250 UART 
with the FT245 and then rolling some code on the Heath side to send and receive 
files to a PC host.

--
Chris Elmquist

> On Dec 15, 2017, at 12:49 PM, systems_glitch via cctalk 
>  wrote:
> 
> It's on my list of things to do -- you can run external clock into DL11 and
> DLV11-J style connectors, and IM6402 UARTs are supposed to go up to 2 mbit,
> so somewhere between 38400 and 2 mbit should be possible. I believe it'll
> require external RS-232 transceivers due to the design of the ones used on
> various DEC boards. As you say, whether or not the bus/CPU can keep up is
> another matter! Figure if I can get any real improvement out of it, I'll
> lay out a board and provide high-speed kits.
> 
> Anyone know of a 40-pin UART with a FIFO? :)
> 
> Thanks,
> Jonathan
> 
> On Fri, Dec 15, 2017 at 1:34 PM, Ethan Dicks via cctalk <
> cctalk@classiccmp.org> wrote:
> 
>> On Fri, Dec 15, 2017 at 9:38 AM, systems_glitch
>>  wrote:
>>> vtserver does indeed work for transferring RL02 contents to a binary
>> image,
>>> suitable for use with SIMH or E11 or whatever.
>> 
>> Yep.  I backed up the RD52 in a new-to-me MicroPDP-11 and it took hours.
>> 
>>> Be advised, it takes a *long*
>>> time, even on a 11/73 with the serial port turned up to 38400 bps.
>> 
>> Has anyone done any console serial port hacking for speed on Qbus or
>> Unibus?  On something integrated like a KDF11-B it might not be so
>> easy, but maybe a DLV11J or a DL11W?
>> 
>> I'd think hitting 115200 would be really sweet, if everything can keep
>> up.  Totally worth some experimentation to see what part gives out at
>> ludicrous speed.
>> 
>> -ethan
>> 

Re: RL02 to PC image

[Chris Elmquist via cctalk]

On Friday (12/15/2017 at 07:57PM +), Henk Gooijen via cctalk wrote:
> 
> I have not yet had time to build/test it, but a few months ago there
> was an RL01/RL02 emulator project on VCF.  You need a PDP-11
> with RL11 controller. The RL0x emultor connects to the RL11
> just as an RL01/RL02 disk drive and you can assign it any drive
> number (0 - 3).
> But what is really nice is that the emulator cooperates with
> real RL drives. So, you can have one real RL0x drive and up
> to 3 “emulated” RL drives. The storage is a flash card.
> The RT-11) command .COPY DL0:*.* DL1: works (where #0 is real,
> and #1 is flash).
> After the copy you pull the flash card and copy it on a PC.

I am interested in this.  Does anyone have a reference/link to the thread
on "VCF"?   Searching for most of these terms has not found me anything...
In fact, searching for ANYTHING on VCF finds me nothing.  Curious.

Chris

-- 
Chris Elmquist

[cctalk] Re: WWVB

[Chris Elmquist via cctalk]

There are a number of WWVB simulator projects out there that will transmit a 
weak but usable signal to your clock after getting sync’d from ntp or GPS NMEA 
time messages.  They were developed to help people develop receivers :-)   One 
in particular uses an AVR and it should be pretty simple to make it do the “old 
protocol”.  You’d then hide this behind your clock and it will sync to it 
instead of the actual WWVB signal.  Solves the protocol problem and the weak 
signal problem from real WWVB with one little circuit.

If Google does not provide, I can dig up some links tomorrow.

Chris N0JCF
--
Chris Elmquist

> On Jan 14, 2024, at 9:10 PM, Bill Gunshannon via cctalk 
>  wrote:
> 
> 
> 
> Will Cooke and Jonathon Chapman explained it.
> 
> A change to the protocol that old clocks don't know about.
> 
> bill

[cctalk] Re: WWVB

[Chris Elmquist via cctalk]

On Sunday (01/14/2024 at 09:55PM -0600), Chris Elmquist via cctalk wrote:
> There are a number of WWVB simulator projects out there that will transmit a 
> weak but usable signal to your clock after getting sync’d from ntp or GPS 
> NMEA time messages.  They were developed to help people develop receivers :-) 
>   One in particular uses an AVR and it should be pretty simple to make it do 
> the “old protocol”.  You’d then hide this behind your clock and it will sync 
> to it instead of the actual WWVB signal.  Solves the protocol problem and the 
> weak signal problem from real WWVB with one little circuit.
> 
> If Google does not provide, I can dig up some links tomorrow.

Hmm. Strange.  I did follow-up shortly after the above post with this
link,

https://www.instructables.com/WWVB-Simulator/

but I don't see that that made it to the list.

Chris

-- 
Chris Elmquist

[cctalk] Re: WWVB

[Chris Elmquist via cctalk]

> 
> Your original email with the link did not make it into the digest, which is 
> what I receive.
> 
> Chirs, Did you also send it directly to Bill. Perhaps that is what he got.
> 
> Bob

Yes, sorry.  I sent the follow-up hastily on an iPad, and the URL I thought I 
was pasting was an image and some junk.  DennisB let me know of my fail as the 
list stripped the image and the junk, leaving nothing to forward. I tried again 
from a real computer where plain text is still a thing and that was what made 
the list.  Bill likely got both attempts.

Anyway, hopefully that particular project is useful or if not, there are 
similar solutions out there.

Chris

[cctalk] Re: Z80 vs other microprocessors of the time.

[Chris Elmquist via cctalk]

Hey, I did that on Sunday afternoons on the Star-100 with Lincoln and his son 
PD when I was in 8th grade.  I never became a manager though :-)

Chris
--
Chris Elmquist

> On Apr 22, 2024, at 3:22 PM, Chuck Guzis via cctalk  
> wrote:
> 
> On 4/22/24 13:02, Wayne S wrote:
>> I read somewhere that the cable lengths were expressly engineered to provide 
>> that signals arrived to chips at nearly the same time so as to reduce chip 
>> “wait” times and provide more speed.
> 
> That certainly was true for the 6600.  My unit manager, fresh out of
> UofMinn had his first job with CDC, measuring wire loops on the first
> 6600 to which Seymour had attached tags that said "tune".
> 
> But then, take a gander at a modern notherboard and the lengths (sic) to
> which the designers have routed the traces so that timing works.
> 
> --Chuck
> 

[cctalk] Re: Z80 vs other microprocessors of the time.

[Chris Elmquist via cctalk]

On Monday (04/22/2024 at 08:55PM -0700), Chuck Guzis wrote:
> On 4/22/24 20:36, Chris Elmquist wrote:
> > Hey, I did that on Sunday afternoons on the Star-100 with Lincoln and his 
> > son PD when I was in 8th grade.  I never became a manager though :-)
> > 
> > Chris
> 
> Trying to remember, was the star the same as the 6000 as far as wiring?
> That is, twisted pair and taper-pin?

I seem to remember (poorly) that it was very small diameter coax but I
don't remember the termination method.

I remember more about the Tek oscilloscope on a cart that we used than
what we were actually doing.

I don't recall that we actually cut and terminated any cables.
We were just measuring the skew and writing it down and then I think a
"professional" was going to come around later and actually adjust the
line length.  Entirely possible we were just doing busy work to stay out
of trouble and not going to be part of the actual solution.  But it was
still educational.

> Gad, that was what, 50 years ago? I remember hunkering between the SBUs
> at ADL with a pillow during the OPEC oil embargo, with my pillow from
> the Ramada and a book.  It was the warmest place in town...

Close. I think 48 yrs.  I first met PD Lincoln in 1976 when I moved into
the Mounds View School district.  Then I discovered his dad was doing
some pretty cool stuff at work...

I think they were working on the CY203 then too but there was still a
Star on the floor which is what we "played" with.

For those playing along, this was the CDC Arden Hills Operations (ARHOPS)
in St. Paul, MN.  The CDC Advanced Design Lab (ADL) was here and it's
where all the supercomputing hardware development took place after
Seymour left CDC.  So, they did the Star-100, CY203, and CY205
there and then in 1983 spun the entire ADL off into what became ETA
Systems and we did the LN2 cooled ETA10 there.

> This California boy wasn't used to Twin Cities winters...

Understood.  It's all I know except for recently experiencing summer
in Albuquerque so we might be 180 degrees (so to speak) out of phase on
that :-)

Chris
-- 
Chris Elmquist

[cctalk] Re: Double Density 3.5" Floppy Disks

[Chris Elmquist via cctalk]

On Monday (05/06/2024 at 06:58PM -0700), Fred Cisin via cctalk wrote:
> Ignorant question:
> 
> Q: When looking for current availability of bulk tape/disk demagnetizers, on
> eBay, I ran into a lot of CD/DVD demagnetizers
> What kind of a problem do they have with magnetism?

I think you can also fix this problem by coloring around the outer edge
of the disc with a green magic marker.  Has to be green though.

Chris
-- 
Chris Elmquist

[cctalk] Re: teletype roll as an RF termination load

[Chris Elmquist via cctalk]

On Thursday (06/13/2024 at 10:46AM -0500), Jon Elson via cctalk wrote:
> On 6/12/24 22:32, Gavin Scott via cctalk wrote:
> > Is it possible they were thinking about really old FAX paper which
> > might have been wet to support marking via an electric discharge
> > through it (and to (slightly) reduce the frequency with which the
> > receiving machine caught fire)?
> 
> Yes, there was teledeltos paper, that had a silver top layer and a carbon
> layer below that.
> 
> A high voltage spark burned away the silver layer and left a black image.

The OP mentioned that the story may have originated at Varian, where they
historically did a lot of work on high power _microwave_ stuff.  I could
imagine that a roll of paper might make an OK attentuator at the end
of a piece of waveguide, into which you can dump a bunch of power.
But it probably isn't going to be a very good impedance match.

I don't see it working well at all at HF, VHF or UHF frequencies if
the RF source (transmitter) is expecting any sort of normal impedance
like a 50 ohm termination-- because how are you connecting the feedline
to this roll of paper?  What is the mechanical and electrical interface
between the unbalanced (or balanced) feeder and the roll of paper?

Maybe they put an actual dummy load resistor inside the roll of paper
and were using it as a heatsink--  you know, before it lit on fire ;-)

Seems like some important details of this story are missing...

Chris N0JCF
-- 
Chris Elmquist

Re: Core memory emulator using non volatile ram.

[Chris Elmquist via cctalk]

On Sunday (12/16/2018 at 10:40PM -0800), Chuck Guzis via cctalk wrote:
> On 12/16/18 11:21 AM, Paul Koning wrote:
> 
> > If you simply want non-volatile memory, the obvious answer is SRAM with 
> > battery backup and a small FPGA to do the interfacing.
> 
> I proposed nvRAM - CMOS SRAM backed by cell-for-cell flash.  Loads SRAM
> from flash on power-up and stores into flash at power-down.  All that's
> needed is a capacitor to extend the power-down cycle a bit.
> 
> Very fast, available in 8 to 32-bit wide architectures, up to 16Mbit per
> package.
> 
> Claims to be guaranteed for 1M power cycles and doesn't require a battery.

These are pretty neat.  Took me a bit to find an example.  They like to
call it "NvSRAM",

http://www.cypress.com/search/psg/1259#/?_facetShow=ss_ppart_family,ss_pinterface,fs_pdensity_kb_,ss_porganization_x_x_y_,ss_ppackage,ss_pfrequency_mhz_,fs_pspeed_ns_,ss_ptemp_classification,fs_pmin_operating_temp_c_,fs_pmax_operating_temp_c_,fs_pmin_operating_voltage_v_,fs_pmax_operating_voltage_v_,fs_pmin_operating_vccq_v_,fs_pmax_operating_vccq_v_,ss_ptape_reel,ss_pautomotive_qualified,fs_part_price&ss_pinterface=Parallel&fs_pmin_operating_voltage_v_=4.5&fs_pmin_operating_voltage_v_=4.5

which is a typical 32K x 8, 5V device.

The "flash" subsystem is something they call SONOS / QuantumTrap technology.

Takes 8mS to STORE the SRAM to the backing store at power down and 20mS
to RECALL it at power up.

The storage cap is typically 68uF so nothing monster.

Chris
-- 
Chris Elmquist

Re: Network cards and Win98SE

[Chris Elmquist via cctalk]

On Monday (05/13/2019 at 10:15PM -0700), Chuck Guzis via cctalk wrote:
> On 5/13/19 9:10 PM, Grant Taylor via cctalk wrote:
> > On 5/13/19 10:04 PM, Tony Duell via cctalk wrote:
> 
> >> Those who know me, for example, will know I have little interest in
> >> physical exercise. But I bought a mat intended for such activities
> >> because it was a suitable material for lininng a carrying case for a
> >> piece of photographic equipment.
> 
> I use yoga mat material as a benchtop cover, photo background, and
> something to cushion my old bones when I'm crouching into a piece of
> gear on floor.  It's cheap--about $12 shipped for a mat from Amazon.
> 
> Never did, nor want to start doing yoga.

But now you are going to be bombarded with ads for yoga pants...

-- 
Chris Elmquist

Re: HP98035 Real Time clock and AC5954N clock chip

[Chris Elmquist via cctalk]

On Friday (06/07/2019 at 11:01AM -0700), CuriousMarc via cctalk wrote:
> > 
> > I wondered if it's actually a digtal watch chip (2.5V could have been a 
> > couple
> > of mercury cells in series, LED watches were not uncommon back then).
> > 
> > In which case it would not normally have come in a 0.6" wide DIP. Perhaps
> > normally it was a bare chip directly mounted on the watch circuit board or
> > something.
> > 
> > The DIP version would be unusual, which is perhaps why we can't find data
> > on it.
> > 
> > -tony
> 
> I think you are on to something. That would make perfect sense.

FWIW, there was an article in Kilobaud magazine, perhaps 1977 or '78
that described connecting a TI LED digital watch to the SS-30 bus in
the SWTPC 6800.

I built this then, wrecking the TI watch as a watch but it made an
excellent RTC for this machine.  Two AA size NiCADs were used to power
the watch and charged through a simple trickle charge when the machine
was powered up.

The interface to the host was through a 6820 PIA, with just the segment
lines and a couple of output bits.  The output bits indeed "pressed"
the buttons on the watch and the code would set it just like a human
would by stepping through each digit in sequence and "pressing" the
other button to increment that digit.

When reading the clock, the code would pretend to set the watch but never
increment any digit.  It would just press the button to advance to the
next digit, stepping through all of the digit positions until it had
read them all (both time and date) and then return this buffered result.

By pretending to set the clock but not actually changing it, it allowed
the code to know which digit was being displayed and therefore it did not
need to have the digit select lines brought into the host.

Chris
-- 
Chris Elmquist

Re: Tektronix Terminal Emulation

[Chris Elmquist via cctalk]

On March 9, 2017 9:00:43 PM CST, Douglas Taylor via cctalk 
 wrote:
>I'm trying to return to the computing days of yesteryear when people 
>hooked graphics terminals to VAXes.
>
>I don't have a Tektronix graphics terminal but I do have a MicroVax II 
>and a laptop running Debian Linux.  Up to now I've been using the
>laptop 
>as a console device and connecting to the Vax using minicom.  I thought
>
>that the laptop would be a natural as a Tektronix type terminal.
>
>On the MicroVax I have just started with PGPLOT and MIIPS, which are 
>scientific plotting packages that run on Vaxes.
>
>I would like to use the laptop to emulate a Tek terminal connected to 
>the Vax through a serial port, but there doesn't seem to be anything 
>available to do that.  Does anyone know of such a thing?
>
>Doug

If you're not wedded to Linux on the laptop, MSDOS Kermit will do pretty good 
DEC VT-{many} and TEK4014 emulation and would be "period correct" for use with 
your VAX :-)

Chris
-- 
Chris Elmquist

Re: Ferroresonant transformer supply repair

[Chris Elmquist via cctalk]

On Monday (09/09/2019 at 05:55PM -0500), Kyle Owen via cctalk wrote:
> On Mon, Sep 9, 2019 at 4:06 PM Marc Howard  wrote:
> 
> > BTW, Genteq is a reputable brand.  It is the former GE capacitor division,
> > hence the name Gen(eral Electric)teq(technology).
> >
> > On Mon, Sep 9, 2019 at 1:02 PM Marc Howard  wrote:
> >
> >> Amazon is your friend:
> >>
> >>
> >> https://www.amazon.com/Capacitor-Motor-Quick-Connect-Snap/dp/B00HRNKI9Q/ref=sr_1_fkmr0_2?keywords=660v+capacitor+8+mfd&qid=1568059220&s=gateway&sr=8-2-fkmr0
> >>
> >> $13 bucks.  Cheep.
> >>
> >
> Awesome! That's much cheaper than I was expecting. I'll make an update when
> I get it installed. It is physically much smaller than the previous one, so
> I'll have to come up with another mounting solution. Maybe I'll find some
> material to wedge underneath the cap to make it around the same height,
> assuming the width is the same; should be able to use the same mounting
> brackets that way.

If you were looking for a taller one than some have found, perhaps this
style fits better,

https://www.alliedelec.com/product/genteq/27l6016/70103256/

-- 
Chris Elmquist

Re: [Simh] Fwd: VAX + Spectre

[Chris Elmquist via cctalk]

On Wednesday (09/18/2019 at 09:19AM -0700), Guy Sotomayor Jr via cctalk wrote:
> 
> 
> > On Sep 18, 2019, at 12:42 AM, Liam Proven via cctalk 
> >  wrote:
> > 
> > On Wed, 18 Sep 2019 at 02:19, Paul Koning via cctalk
> >  wrote:
> >>> ...
> >> Speaking of timing, that reminds me of two amazing security holes written 
> >> up in the past few years.  Nothing to do with the Spectre etc. issue.
> >> 
> >> One is the recovery of speech from an encrypted VoIP channel such as 
> >> Skype, by looking at the sizes of the encrypted data blocks.  (Look for a 
> >> paper named "Hookt on fon-iks" by White et al.)  The fix for this is 
> >> message padding.
> >> 
> >> The other is the recovery of the RSA private key in a smartphone by 
> >> listening to the sound it makes while decrypting.  The fix for this is 
> >> timing tweaks in the decryption inner loop.  (Look for a paper by, among 
> >> others, Adi Shamir, the S in RSA and one of the world's top 
> >> cryptographers.)
> >> 
> >> It's pretty amazing what ways people find to break into security 
> >> mechanisms.
> > 
> > ... Wow.
> > 
> > *Wow.*
> > 
> > Thanks for those!
> 
> In the deep dark days of yore, I recall an actual demonstration of being able 
> to read/replicate the contents of the screen (CRT) of a PC by looking at the 
> AC (e.g. mains) that the PC was plugged into.  Admittedly it was relatively 
> low fidelity, but yikes!

https://en.wikipedia.org/wiki/Van_Eck_phreaking

-- 
Chris Elmquist

Re: Interesting device on eBay -- CDC clock generator?

[Chris Elmquist via cctalk]

Unfortunately, I have not seen such a drum.  

The device in question though really looks RF-ish to me.  The feedthrough caps 
suggest DC control voltages that might bias the diodes to switch any port to 
the center and then there’s some matching going on with the meandering inductor 
on the PCB and the caps at the center.  Maybe some kind of radio direction 
finder (RDF) gizmo??

Seller is here in MN so CDC and Univac ties are a good possibility but we also 
had a large presence of the MIL avionics outfits like Honeywell, LockMart, GD, 
etc. in the day.

Chris
--
Chris Elmquist

> On Jan 19, 2020, at 1:18 PM, Chuck Guzis via cctalk  
> wrote:
> 
> 
>>> On 1/17/2020 12:11 AM, William Maddox on CCTalk via cctalk wrote:
>>> The seller thinks this may be a drum memory, but it is clearly not.  
>>> My guess is that it is some kind of clock generator.  Anyone recognize
>>> this?
> 
> One candidate is the high-speed drum from the STAR (early Cyber 200's)
> MCU.   Having seen only the outside of the drum unit, I can't say for
> certain.  Perhaps Chris Elmquist has seen the innards of one.
> 
> --Chuck

Re: HPE OpenVMS Hobbyist license program is closing

[Chris Elmquist via cctalk]

And if they went that way, it would be quite a big event in the supercomputing 
world because HPE now own both of the companies formerly known as SGI and Cray.

Someone on the inside is attempting to explore why this is happening.  If I 
hear anything, I will report back.

If something positive were to occur, IRIX might be able to be saved too.

Chris
--
Chris Elmquist

> On Mar 10, 2020, at 8:03 PM, John H. Reinhardt via cctalk 
>  wrote:
> 
> On 3/10/2020 6:46 PM, Doug Jackson via cctalk wrote:
>> Having worked for them in also not surprised.
>> 
>> When they absorbed Compaq their culture changed.  Significantly for the
>> worse.
>> 
>> I'd be stunned if they existed in a form other that selling printers and
>> ink cartridges in 5 years time.
>> 
> They can't, they have no printers or ink to sell.  They already broke the 
> company up into HP - printers, ink and PC's and HPE - Servers, etc (including 
> OpenVMS until it was sold or licensed to VSI).
> 
> -- 
> John H. Reinhardt
> 

Re: HPE OpenVMS Hobbyist license program is closing

[Chris Elmquist via cctalk]

On Wednesday (03/11/2020 at 10:46AM -0400), Ethan O'Toole wrote:
> >If something positive were to occur, IRIX might be able to be saved too.
> >Chris
> 
> Years ago us SGI hobbyists were able to talk to SGI about this and a
> huge problem SGI had with any kind of hobbyist license for IRIX or
> turning it free is it's fully of licensed 3rd party stuff. But maybe
> now that's it's expired, or all the companies things were licensed
> from are gone.

Right.  I think the challenge(s) are in this space and whether or
not anyone there would have bandwidth or interest in addressing them.

No promises but my contact is at a fairly high level within HPE (and
formerly SGI) so I am hopeful it will at least get discussed.

Chris
-- 
Chris Elmquist

Re: pdp11/05 key?

[Chris Elmquist via cctalk]

CDC had a memory manufacturing facility in SE Asia, staffed with mostly young 
Asian women.
An older colleague at ETA helped set it up (he just passed away; RIP Carl).

He called it the Hong Kong Core House.

--
Chris Elmquist

> On Apr 9, 2020, at 12:44 PM, Fred Cisin via cctalk  
> wrote:
> 
> 
>> 
> MOST of the other PDP machines use the XX2247 key, which is a tubular one.
> But, THIS thread is about the weird one that is NOT tubular.
 Here is my locksmith-cut 11/05 key attached to my pdp11 keyfob:
 https://www.thingiverse.com/thing:3110483
>>> The key fob is pretty cool!
>> 
>> But, we like hardcore porn.
>> How about some pictures of the machine?
>> (key in the lock, with covers off, and panels open!)
> 
>> On Thu, 9 Apr 2020, Norman Jaffe wrote:
>> I hope that you mean 'hardware porn', not 'hardcore porn'... :)
> 
> We like hardcore hardware.
> Got any pictures of bare core planes?
> 

Re: pdp11/05 key?

[Chris Elmquist via cctalk]

> On Apr 11, 2020, at 4:33 AM, Liam Proven via cctalk  
> wrote:
> 
> On Sat, 11 Apr 2020 at 04:05, Chris Elmquist via cctalk
>  wrote:
>> 
>> CDC had a memory manufacturing facility in SE Asia, staffed with mostly 
>> young Asian women.
>> An older colleague at ETA helped set it up (he just passed away; RIP Carl).
>> 
>> He called it the Hong Kong Core House.
> 
> There's a few mentioned of this here and there around the web, e.g.
> 
> http://bjruss.com/SAGE.html
> 
> & in
> 
> https://books.google.cz/books?id=Q7ffAwAAQBAJ&lpg=PA102&ots=nkzF7wQT4i&dq=%22Hong%20Kong%20Core%20House%22&pg=PA103#v=onepage&q=%22Hong%20Kong%20Core%20House%22&f=false
> 
> What I don't get is why pleasingly-assonant phrase causes the great
> amusement it seems to. I think it's a reference to something else I
> don't know. Can anyone give me a pointer?

This might be one of those jokes that if you have to explain it, it looses the 
punch ...  but I’ll try,

There used to also be something called a Hong Kong Whore House, similarly 
staffed with young Asian women, but they didn’t make core planes there.

—
Chris Elmquist 

Re: Dixie Canner CPT 8000?

[Chris Elmquist via cctalk]

Ya. And it’s not from Michigan but Minnesota!

You betcha.

--
Chris Elmquist

> On Apr 24, 2020, at 7:00 PM, Fred Cisin via cctalk  
> wrote:
> 
> 
>> 
>>> What in the world is this?
> 
>> On Fri, 24 Apr 2020, Adrian Graham via cctalk wrote:
>> It’s a word processor, pure and simple. I have the later version and have 
>> kind of been collecting tales of the Cassette Power Typing company of 
>> Michigan -
>> http://binarydinosaurs.co.uk/Museum/cpt
> 
> Thank you for a delightful page.  I hadn't previously noticed it.
> 
> 
> Trivial corrections:
> 
> In Nov 2005 update, it says that the 9000 had an 8086 processor.
> In Jan 2007 update, it says that Win 3.1 was run on it.
> Windows 3.10 required A20 support, and would not run on the 8088/8086, so 
> that would have had to have been Windows 3.00,
> OR the 9000 processor was 80X86, specifically 80286.
> OR, the 9000 got a processor update.
> (The pictures at the bottom of the page, of ISA boards, are clearly 16 bit 
> ISA, which would be 80286, not 8086)
> 
> In Sep 2008, Gary Simpson seems to have confused Double-SIDED with 
> Double-DENSITY. Punching another hole is needed to convert 8" disks back and 
> forth between single and double SIDED.   and is unrelated to density.
> He also mentioned 1771 FDC, which was, indeed, FM not MFM.
> (He would not be the first person to conflate capacity with density, and 
> think that using both sides doubled the DENSITY; it doubled the capacity, and 
> therefore the density of the filing cabinet, but not the "density" of the 
> recording format.)
> 
> 
> 
> At one time, I received a 3.5" double density sample disk that was clearly 
> labelled "CPT CP/M-80"   It was obviously CP/M file system, and I easily 
> implemented that format in XenoCopy.  (It would not have been "easily" if it 
> weren't CP/M, MS-DOS, Stand-Alone BASIC, P-system, nor TRS-DOS)
> Was that a different CPT?  Similar three letter name COULD be something else 
> entirely.
> Or had they done some different drives?
> Or was that a customer modification?
> Gary Simpson mentions 1771 FDC, which was single density only.
> Did any of the CP/M models (pre 80x86) have double density? (likely a 179x 
> FDC, which was an easy upgrade from the 1771, or a whole different FDC, such 
> as the NEC765).
> It didn't HAVE to be pre-80286; it was possible to run a Z80 emulator on PCs, 
> but few had reason to do so.
> 
> --
> Grumpy Ol' Fred ci...@xenosoft.com

IBM 3178 keyboards available in MN

[Chris Elmquist via cctalk]

A friend has unearthed approximately (5) of these IBM keyboards in his
dad's shed in MN.  These are not PC keyboards but instead likely 3178
terminal keyboards.  They probably came out of 3M a very long time ago.

https://drive.google.com/file/d/1B8kw9xdaeikwzKzyL0ts3HZZg96K7Yov/view?usp=sharing

I have persuaded my friend not to trash them until I see if there is
interest in them here.

They are dirty and their working status is completely unknown.

Contact Gary: 

w0ghz(-at-)comcast.net

if you are interested in them.

Reference:

IBM 6052101
https://deskthority.net/wiki/IBM_%22Blue_Switch%22_3178-C3_Terminal

https://terminals-wiki.org/wiki/index.php/IBM_3178

Chris
-- 
Chris Elmquist

Re: Farewell Etaoin Shrdlu

[Chris Elmquist via cctalk]

And Lincoln had MN license plate “ETAOIN” on his rusted out Ford van and one of 
the other guys in our “wiz kid” bunch had “SHRDLU” on his plates.

We later learned that the Eta were some kind of Spanish terrorist group and so 
Neil liked that story better— we were going to terrorize the supercomputer 
world with this ETA-10.

cje
--
Chris Elmquist

> On Jun 17, 2020, at 3:28 PM, Chuck Guzis via cctalk  
> wrote:
> 
> On 6/17/20 12:25 PM, Liam Proven via cctalk wrote:
>> https://archive.org/details/FarewellEtaoinShrdlu
>> 
>> 28min documentary on the last ever edition of the NY Times to be
>> printed using hot metal -- before they switched to what are now a
>> quite choice assortment of late-'70s minicomputers. I think I spotted
>> a PDP, a Data General and some IBM device, but I am no expert in this
>> era.
>> 
> 
> When I was in college, I went on a weekend trip with a friend to see
> where he worked during the summer.  It was a print-shop, complete with
> both letterpress and offset--and a Linotype ("pot" heated with natural
> gas).  The local advertising circular was still set with hot type and I
> witnessed the operation of that contraption.  Noisy and wonderful.
> 
> See the Twilight Zone episode "Printer's Devil" for another sample.
> 
> I was told that most newspaper pressmen were alcoholics, as it blunted
> the effect of the then-toxic inks used in printing.
> 
> Anent ETAOIN:  Early on in the formation of the CDC spinoff, ETA
> Systems, I asked Neil Lincoln what "ETA" stood for.  He related the
> story of his son and ETAOIN SHRDLU.  Back then, the name of the
> supercomputer was referred to as the GF-10; later changed to the ETA-10.
> 
> (GF standing for GigaFLOP).
> 
> --Chuck
> 

Re: mail on spool as G-d intended was Re: Future of cctalk/cctech

[Chris Elmquist via cctalk]

> On Jun 17, 2020, at 3:43 PM, Cameron Kaiser via cctalk 
>  wrote:
> 
> 
>> 
>>> I read this list on PINE, on a shell account at my ISP.
>> 
>> Barbarian!  At least upgrade to Alpine.  (That's what I use.) :D
> 
> Philistines, all of you. I use a hacked version of Elm.

And what’s wrong with Mutt?


I have yet to suffer a phishing attack with that.

Chris

Re: mail on spool as G-d intended was Re: Future of cctalk/cctech

[Chris Elmquist via cctalk]

> On Jun 17, 2020, at 3:46 PM, Diane Bruce via cctalk  
> wrote:
> 
> On Wed, Jun 17, 2020 at 01:41:39PM -0700, Cameron Kaiser via cctalk wrote:
 I read this list on PINE, on a shell account at my ISP.
>>> 
>>> Barbarian!  At least upgrade to Alpine.  (That's what I use.) :D
>> 
>> Philistines, all of you. I use a hacked version of Elm.
> 
> mutt!

Ya! Exactly.  Woof.


cje

Re: Off topic ?

[Chris Elmquist via cctalk]

On Tuesday (08/25/2020 at 04:36PM -0400), Paul Koning via cctalk wrote:
> Not sure if this is off topic, but anyway..
> 
> There was also one with "tree" in its name, don't remember its full name and 
> I think they shut down. 

Smalltree?  They are some former SGI guys here in MN,

https://small-tree.com/about-us/

-- 
Chris Elmquist

Re: Restoring a VT50 (VT52 actually) .

[Chris Elmquist via cctalk]

On Thursday (12/28/2017 at 11:58AM -0800), Chuck Guzis via cctalk wrote:
> On 12/28/2017 11:44 AM, Stefan Skoglund via cctalk wrote:
> 
> > Surströmming isn't a christmas tradition.
> > 
> > It is more like a late august,september tradition (or in summer together
> > with the season potatoes, onion and bread.)
> > 
> > the  sale of this year surströmming was until 1998 legally delayed until
> > the third thursday in august (the herring is fished in early spring
> > april-may.)
> 
> Neither are selenium rectifiers a Christmas tradition--at least not in
> any society that I know of.
> 
> Just trying to throw a little aroma into the mix.   I suppose one could
> also add durian for a memorably odoriferous experience.

I worked for a startup back around 2001 that liked to name their servers
after various fruits.   When the Compaq Itanium box arrived, I was the
one that picked the hostname "durian" for it...

My family has a tradition of Doppa i Grytan on Christmas Eve.  I think the
awesome smell of the fresh rye bread cancels out any burning rectifiers
or durian fruit by a long shot ;-)

Chris
-- 
Chris Elmquist

Re: Help diagnosing boot issue SWTPC 6800

[Chris Elmquist via cctalk]

You should also verify that you have solid +8V and +/- 12V on the
backplane.

In one of my SWTPC 6800 machines, I found that the white Molex connector
on the power supply filter board had degraded contacts that over time
(a long time!) where heating and actually melted some of the connector
shell, made the contacts further crappy and resulted in too much drop
in the +8V rail so that all the downstream regulators weren't happy.

I replaced the on-board connector with one on wires, repaired the toasted
PCB and now the machine runs fine again.  The new connector floats in
the air a few inches above the PCB and this actually makes it easier to
plug and unplug if needed.

Chris

On Monday (01/01/2018 at 02:17PM -0800), Brad H via cctalk wrote:
> 
> 
> I had that happening on mine.. came down to a bad RAM board.
> 
> 
> Sent from my Samsung device
> 
>  Original message 
> From: Nick Allen via cctalk  
> Date: 2018-01-01  10:32 AM  (GMT-08:00) 
> To: cctalk@classiccmp.org 
> Subject: Help diagnosing boot issue SWTPC 6800 
> 
> Hey everyone, Happy New Years!  I am thankful for an active community 
> that enjoys helping each other learn, and today I am coming with an ask 
> for help.
> 
> I have a SWTPC 6800 and ADM3A terminal, I can get it to boot, and when 
> it boots it will continue to boot for several hours.  But getting it to 
> successfully boot takes upwards of 100 power OFF and ON cycles.  The 
> other 99 times, I get a continuous stream of random ASCII characters 
> (see video link below).  It's my first time seeing this type of issue 
> that happens intermittently, and wondering if anyone has any insights in 
> what might be causing this.  I suspect its a faulty IC on the Processor 
> board that resets or controls the OS reset, will need to deep dive and 
> diagnose, but thought I would ask for some direction first.
> 
> https://www.youtube.com/watch?v=Ci4vhPn-3PE
> 
> Thanks in advance!
> 
> -Nick
> 
> 
> 
> 

-- 
Chris Elmquist

Re: Writing emulators [Was: Re: VCF PNW 2018: Pictures!]

[Chris Elmquist via cctalk]

> On Feb 21, 2018, at 3:52 PM, Chuck Guzis via cctalk  
> wrote:
> 
>> On 02/21/2018 12:28 PM, Al Kossow via cctalk wrote:
>> That actually just came up for discussion in a donation review meeting this 
>> week at
>> CHM.
>> 
>> I don't know if they're that interesting w/o the software and documentation, 
>> and even
>> then, these things were all locked down with licenses, except for the really 
>> early ones
>> like Daisy and Valid.
>> 
>>> On 2/21/18 11:37 AM, Chuck Guzis via cctalk wrote:
>>> 
>>> Speaking of emulation, does anyone here collect old ZyCAD or Cadence
>>> hardware emulation rigs?
> 
> Definitely lots of proprietary stuff.  I had a couple of friends who
> worked for ZyCAD back in the day.  I got the impression that they were
> only exposed to a piece of the puzzle.
> 
> Also, expensive as hell.
> 
> --Chuck

We had a lot of ZyCAD stuff at ETA because we just had to drive a couple miles 
up the road to get it ;-)  Lots of the ETA brass were buddies with the ZyCAD 
brass because they all came from ADL.

We used it to simulate the ALSI 20K gate arrays before they were built.  The 
gear we had was usually plugged into some Apollo headless nodes, which I think 
were Multibus backplanes?? and then accessed over the Domain network.

Chris

Re: IBM 6094-010 "Dials" protocol?

[Chris Elmquist via cctalk]

On Sunday (03/25/2018 at 07:11AM -0700), Mark J. Blair via cctalk wrote:
> 
> 
> > On Mar 24, 2018, at 22:29, Michael Brutman via cctalk 
> >  wrote:
> > 
> > Picture here: https://i.imgur.com/ClCw070.jpg 
> > 
> 
> Neat! I haven't seen one of those since 1987, when I briefly played with a 
> workstation that had one of those in an unguarded computer room in college. 
> It was running some sort of CAD demo in which you could rotate, translate, 
> and scale a wireframe model with the dials. I seem to recall that it was 
> propped up diagonally on some sort of stand, but I don't remember if that was 
> a standard feature vs. something cobbled together locally.
> 
> Good luck learning how to talk to it. I can think of a number of different 
> applications in which a physical interface like that might be nice.

Maybe there's some relationship to the SGI dial boxes??  I have an SGI
one but don't know anything about the IBM ones.  They were built by
Danaher and Seiko and both SGI and Sun offered those models...

https://en.wikipedia.org/wiki/Dial_box

http://yehar.com/blog/?p=3471

https://github.com/hanshuebner/sgi-dialbox-usb/blob/master/dialbox.py

Chris
-- 
Chris Elmquist

Re: Dilog DQ604 RL01 / RL02 emulation on ST506/ST412 disk.

[Chris Elmquist via cctalk]

On Tuesday (08/28/2018 at 11:25AM +0200), Mattis Lind via cctalk wrote:
> Den sön 26 aug. 2018 kl 09:26 skrev Paul Birkel via cctalk <
> cctalk@classiccmp.org>:
> 
> > Which length band did you find worked best as a replacement?
> >
> 
> I used the white three inch plastiband. Rik Bos told me that the best way
> is to heat the old band slightly. I used a SMD desoldering air gun which I
> set to 100 degrees centigrade and then blowed heat air onto the tape from
> some distance until it changed from a white matte surface into a darker
> brown surface.

Hmm.  3" plastiband seem to be rare or my Google-foo is pretty bad.

Do you have a source for these?

I have found only 2-1/8", 4-1/4" and 6" so far.

Tack.
-- 
Chris Elmquist

Re: Dilog DQ604 RL01 / RL02 emulation on ST506/ST412 disk.

[Chris Elmquist via cctalk]

On Tuesday (08/28/2018 at 08:22PM +0200), Mattis Lind wrote:
> Den tis 28 aug. 2018 kl 19:50 skrev Chris Elmquist :
> 
> > On Tuesday (08/28/2018 at 11:25AM +0200), Mattis Lind via cctalk wrote:
> > > Den sön 26 aug. 2018 kl 09:26 skrev Paul Birkel via cctalk <
> > > cctalk@classiccmp.org>:
> > >
> > > > Which length band did you find worked best as a replacement?
> > > >
> > >
> > > I used the white three inch plastiband. Rik Bos told me that the best way
> > > is to heat the old band slightly. I used a SMD desoldering air gun which
> > I
> > > set to 100 degrees centigrade and then blowed heat air onto the tape from
> > > some distance until it changed from a white matte surface into a darker
> > > brown surface.
> >
> > Hmm.  3" plastiband seem to be rare or my Google-foo is pretty bad.
> >
> > Do you have a source for these?
> >
> > I have found only 2-1/8", 4-1/4" and 6" so far.
> >
> 
> The SF-7000 contain a number of different sizes. 1 1/2 inch, 2 1/8 inch, 3
> 5/8, 4 1/4 inch and 6 inch
> 
> http://www.officedirectsupply.com/sf7000_baumgartens_plastiband_77071_prd1.htm
> 
> On the other hand I haven't found a source for the 6 inch variant (that
> actually could deliver them) other than in the mixed package.

Got it. Thanks.  So, 3-5/8" is actual.  I was being too picky about your
3" statement :-)

It seems to be well known that the number of each size you get in the
SF-7000 package is, umm, random...  so a guy needs to get several packages
and hope for plenty of white ones.

Thanks again,

Chris
-- 
Chris Elmquist

Re: Advice requested on proper disposal of Seagate ST3000DM001 disk drives

[Chris Elmquist via cctalk]

On Friday (09/21/2018 at 11:42AM -0600), Eric Smith via cctalk wrote:
> On Fri, Sep 21, 2018 at 11:28 AM, Fred Cisin via cctalk <
> cctalk@classiccmp.org> wrote:
> 
> > Put it in a gift-wrapped box next to you on the bus.
> > Whoever steals it will get just what they deserve.
> >
> 
> :-)
> 
> But actually I wouldn't wish ST3000DM001 drives on my worst enemy!

Ship them across town by FedEx,

https://www.youtube.com/watch?v=WCGBNj-aSwA

-- 
Chris Elmquist

Re: Motor generator

[Chris Elmquist via cctalk]

> On May 5, 2021, at 10:37 AM, Chuck Guzis via cctalk  
> wrote:
> 
> On 5/5/21 5:18 AM, Paul Koning wrote:
> 
>> An earlier message commented on the whine from power converters.  I
>> don't know how common this practice was, but at the University of
>> Illinois PLATO system which had a pair of 6500 systems, the
>> motor-generator was located near the elevator machinery in a corner
>> of the building, far from the computer room.  Yes, it was noisy, but
>> no one spent any time in that location.  The computer room was -- by
>> mainframe standards certainly -- rather quiet.  Of course it helps to
>> have liquid cooling, so there weren't many noisy fans to deal with.
> 
> It was the "white noise" from the vacuum pumps in the tape drive banks
> that drove me nuts after a few hours.  After 8 hours or so, I sometimes
> found my hands shaking.  Of course this facility had a very large
> machine floor with several full-sized installations.  Eventually,
> management provided ear protection.
> 
> As far as any "whine"--I vaguely recall hearing a high-pitched whine if
> I put my ear close to the power adjustment panel in a CDC Cyber--but it
> was barely audible.
> 
> As far as the MG sets themselves, I never went there--any noise at
> SVLOPE was drowned out by the fans in the cooling tower.  I don't recall
> where the power equipment at ARHOPS was located.
> 
> --Chuck
> 

We had a room on the ground floor at ETA that housed an MG set that ran the 
CY205 (and maybe the 835 and 875 too) in the basement.  They had isolated the 
MG from the mounting pretty well in addition to sound proofing the room because 
with door closed, you couldn’t really tell it was in there— which was nice 
because the room was right off the main entry hallway :-)

Chris

Re: Motor generator

[Chris Elmquist via cctalk]

On Thursday (05/06/2021 at 08:37PM -0700), Chuck Guzis wrote:
> On 5/6/21 7:47 PM, Chris Elmquist wrote:
> > We had a room on the ground floor at ETA that housed an MG set that
> > ran the CY205 (and maybe the 835 and 875 too) in the basement.  They
> > had isolated the MG from the mounting pretty well in addition to
> > sound proofing the room because with door closed, you couldn’t really
> > tell it was in there— which was nice because the room was right off
> > the main entry hallway :-)
> 
> About all I recall from the few times that I visited the ETA facility
> were the chairs upholstered in bright primary colors.

The HQ building (nee BTC) was built just a year before ETA started,
so 1982 or so.  But somehow it ended up with very 70s-ish decor, even
if it was all new 70s-ish decor.  It's possible they wanted all the guys
that moved down from ARHOPS and ADL to still feel at home...

cje
-- 
Chris Elmquist

Re: Motor generator

[Chris Elmquist via cctalk]

On Friday (05/07/2021 at 09:03AM -0700), Chuck Guzis wrote:
> On 5/7/21 5:53 AM, Chris Elmquist wrote:
> 
> > The HQ building (nee BTC) was built just a year before ETA started,
> > so 1982 or so.  But somehow it ended up with very 70s-ish decor, even
> > if it was all new 70s-ish decor.  It's possible they wanted all the guys
> > that moved down from ARHOPS and ADL to still feel at home...
> 
> Oh, yeah, brightly painted exposed pipes, too.  Probably inspired by the
> 1970's Centre Pompidou in Paris.
> 
> CDC native decor was the usual 60's drab.   The ubiquitous brwon
> vinyl-and-fabric Steelcase chairs, for example.  Another hangover,
> thankfully abandoned, was the OCR-looking typeface on office typewriters.

Yup.  There were a fair number of the gun-metal grey desks that looked
like they had come back from the Korean war or something that some of
the guys brought from ADL to ETA.  Wanted to keep their own desk!

> 
> I hated the look of that so much that I managed to snag an IBM Model B
> Executive with proportional spacing when a GM's secretary moved to a
> Selectric.

Ha. That really was a CDC trademark in all of their documentation.

I must have grown up on the wrong side of the tracks because I remember
thinking it was kind of cool.  I even went so far as to seek out an
OCR type wheel for my Diablo printer so that I could print listings
at home that looked like the ones I did at work :-)  What can I say?
I was young and impressionable then...  LOL.

cje
-- 
Chris Elmquist

Re: What happened to control-data.info and controlfreaks.org?

[Chris Elmquist via cctalk]

On Thursday (11/18/2021 at 01:53AM -0500), Jim Carpenter via cctalk wrote:
> Is anybody able to access these sites? I just get redirected to Google.

I have not received any email from the controlfreaks mailing list for
over 60 days either.  I automatically expire stuff older than 60 days
and the mailbox is totally empty now.

Chris
-- 
Chris Elmquist

[cctalk] Re: Dysan Alignment and Performance Testers

[Chris Elmquist via cctalk]

Just curious if you had a known "good" drive, a golden unit so to speak,
that was well aligned with an authentic alignment diskette-- could you
then use that drive to write plain old data diskettes that the downstream
users would then align their drives to?

Could they simply maximize the read signal coming off that data diskette?
I'd assume that the data written would include track number in the data
so a piece of software could help ensure you are actually on the correct
track while you are tweaking the gizmos to maximize the read signal.

I'd assume you could get access to the raw read signal (before or after
some read amplifier) on the drive and put your scope there to help you
maximize that signal level.

Wouldn't this result in aligning that user's drive to the sweet spot
of the track(s) on the diskette if the assumption is that the data
diskette was written with tracks in the right place?

cje
-- 
Chris Elmquist

[cctalk] Re: Comstar Computer Systems System 4 Intel 4004 based Industrial Computer

[Chris Elmquist via cctalk]

I know that LeRoy Anderson and worked with him in the early 90s.  I do not know 
if he is still on the planet however.  He was quite a name in the Twin Cities 
electronics industry in the 70s, 80s and early 90s.  I worked with him at 
Multi-Tech Systems, a fairly prominent modem manufacturer during that 
timeframe.  He was a consultant there and had a big role in helping 
Multi-Tech’s founder, Raghu Sharma, become a citizen, get his PhD at UofMN and 
start the company.  LeRoy was also an EE professor at UofMN and dabbled in 
various RF heating technologies I believe.

I have two C4040 (prerelease silicon) chips that I found in a box in the attic 
at Multi-Tech one day over the lunch hour sometime in 1979. Nobody knew what 
they were or why they were there but I kept them, still have them, and they 
run.  LOL.

Chris
--
Chris Elmquist

> On May 13, 2025, at 9:00 AM, Christian Liendo via cctalk 
>  wrote:
> 
> Back in Nov of 2023 Ed Sharpe asked the following: “Was there ever a
> COMPUTER using a 4004 that you could really do something or did that
> finally arrive with the 8008”
> https://classiccmp.org/mailman3/hyperkitty/list/cctalk@classiccmp.org/message/LYKGFANNPN6S75X3IUEZVFDRVPD5MQKF/
> 
> I hope to answer that question, or at least spark a discussion.
> 
> For a number of years now I have been researching this computer called
> a Comstar System 4 which is based on the Intel 4004. The Comstar
> Corporation of Minneapolis was a developer of microcomputer control
> and automation systems and in 1972 released the System 4
> microcomputer. Comstar built a general purpose capable computer that
> could be programmed to do a multitude of tasks but their market focus
> was industrial automation. Comstar was eventually bought by Warner &
> Swasey in 1974 to integrate their computers into the Warner & Swasey
> product line. Warner & Swasey was a huge manufacturer of industrial
> machines. So they bought Comstar to be their Computer division. In
> fact it was called " Warner & Swasey Comstar Microcomputer Electronic
> Products" Warner and Swasey also licensed the Micral N to do the same
> and we call the Micral N a computer. The Micral N was designed for
> process control, but we know of it as a computer.
> 
> Now before anyone argues about if this is a computer or not, I will
> state the following.
> 
> It was called a Microcomputer in the ACM titled "Development of a
> portable compiler for industrial microcomputer systems "
> It was called a Microcomputer in Electronics Magazine July 11th 1974
> It was listed as a Microcomputer in "Auerbach Guide to Minicomputers"
> April 1976 &  Winter 1976 - 1977
> It was listed as a Microcomputer in Datamation Magazine Dec 1974
> It was called a Microcomputer in "A MICROCOMPUTER BASED SUBSTATION
> CONTROL SYSTEM" The University of Oklahoma, Ph.D., 1975 Engineering,
> electronics and electrical Page 90
> It was listed as a Microcomputer in the Intel MCS 4 User Manual Feb
> 1973 page 171
> It was listed as a Microcomputer in Electronics Magazine Jan 1973,
> they promote the 4004 and 8008 and use the System 4 as an example.
> The reality is this existed, was 4004 based and there were discussions
> about it in the media at the time.
> 
> Anyway I wanted to see if there was more interest in researching this 
> computer.
> 
> I listed a number of articles and references below that either discuss
> Comstar, The Warner Swasey Computer Division, the “System 4” or “Star
> 4” Computer.
> 
> All the Manuals and schematics I was able to upload to archive.org
> https://archive.org/search?query=subject%3A%22Comstar+Computer+Systems%22
> 
> Computer History Museum's Archive of the Manual
> https://www.computerhistory.org/collections/catalog/102686568
> 
> Pictures of the items I have collected so far
> https://imgur.com/a/Oyts3A9
> 
> The website "Internet Scripophily Museum of Computing" has a page on
> the history of The Warner & Swasey Company. It's a decent timeline of
> the company
> http://ismoc.blogspot.com/2017/06/the-warner-swasey-company.html
> 
> "Development of a portable compiler for industrial microcomputer
> systems" by LEROY H. ANDERSON The Warner & Swasey Company, it
> discusses the system and has images on the unit.
> https://www.computer.org/csdl/pds/api/csdl/proceedings/download-article/12OmNzRqdD4/pdf
> 
> In the ACM's archives "Development of a portable compiler for
> industrial microcomputer systems" by LEROY H. ANDERSON The Warner &
> Swasey Company, it discusses the system and has images on the unit.
> https://www.computer.org/csdl/pds/api/csdl/proceedings/download-article/12OmNzRqdD4/pdf
> 
> Electronics Magazine July 11th 1974  Article: Industrial Automatic
> control proliferates, they are mentioned on page 84 & 85
> https://www.worldradiohistory.com/Archive-Electronics/70s/74/Electronics-1974-07-11.pdf
> 
> There is a mention about the compiler in the IEEE on Page 25 under
> Compiler Programmer
> https://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=6368812
> 
>

[cctalk] The Big Rewrite (American Pie parody)

[Chris Elmquist via cctalk]

Apologies if this is a dupe here but I don't remember seeing it,

https://www.youtube.com/watch?v=xCGu5Z_vaps

:-)

-- 
Chris Elmquist

[cctalk] Re: Ferroresonant transformer mystery

[Chris Elmquist via cctalk]

I found this,

https://www.solidstatecontrolsinc.com/-/media/ameteksolidstatecontrols/documentation/white-papers/ferroresonant-transformers-white-paper.pdf

which says in section 1.8 on page 8,

1.8 FREQUENCY SENSITIVITY

Referring to Figure 1.3, we see that the slope of the straight line
varies inversely with the square of the input frequency. As the frequency
increases, the slope of the straight line decreases and point C moves up
to a higher value of flux density. The output voltage of the regulator
is, therefore, sensitive to frequency variations, the relation being a
1.4% change in output voltage for a 1% change in input frequency


Chris


On Wednesday (07/16/2025 at 09:06PM +), Brendan McNeill via cctalk wrote:
> Hi Jon
> 
> I restored a PDP-8 straight 8 that had a similar PSU.  I am here in New 
> Zealand with 230v 50Hz.  I used a step down transformer 230v -> 110v but of 
> course retained the 50hz.It worked just fine.  I did replace the 
> capacitor in question however.  They contain PCB’s so use gloves and dispose 
> with care.
> 
> Kind regards
> Brendan
> 
> 
> --//
> bren...@mcneill.co.nz
> +64 21 881 883
> 
> 
> 
> From: Jon Elson via cctalk 
> Date: Thursday, 17 July 2025 at 02:50
> To: Tom Hunter via cctalk 
> Cc: Jon Elson 
> Subject: [cctalk] Re: Ferroresonant transformer mystery
> 
> On 7/16/25 09:13, Tom Hunter via cctalk wrote:
> > Recently I got a nice and complete PDP-8/s from the US. The power supply
> > uses a ferroresonant transformer which in addition to the standard primary
> > and secondary windings has a separate 2.3H winding connected in series to a
> > 2uF 660VAC capacitor forming a resonant "tank" circuit. The transformer's
> > secondary side and the resonant circuit are operated in saturation. There
> > is a magnetic shunt to prevent the primary side going into saturation as
> > well. It accepts a wide input voltage range, but is very sensitive to the
> > input frequency of 60Hz. This is quite a nice if not elegant design for the
> > period in question, but maybe not the most efficient.
> >
> > As I live in Australia I get 240VAC and 50Hz as opposed to the US 115VAC
> > and 60Hz.
> >
> > I can easily convert our 240VAC to 115VAC with a step-down transformer, but
> > cannot easily supply 115VAC at 60Hz. So I was considering using a step-down
> > transformer to get the 115VAC, but modify the resonant "tank circuit" for
> > 50Hz.
> >
> > Unfortunately there is some magic I don't understand. The resonant
> > frequency of a LC circuit with L=2.3H and C=2uF is about 75Hz not the
> > expected 60Hz.
> >
> > Otherwise I could just solve the standard LC resonant circuit formula for C
> > and plug in 50Hz and 2.3H to get the required C.
> >
> > Obviously ferroresonant transformers are more complex than this former
> > software engineer can grasp. Could any experienced EE with relevant
> > transformer knowledge please chime in and help me understand how to
> > redimension the tank circuit to use 50Hz instead of the original 60Hz input.
> >
> > Obviously I could replace the entire power supply with two modern switch
> > mode supplies to create the two rails, but it would be really nice to keep
> > the original supply and just reversibly adapt it for 50Hz.
> 
> That L is probably different when the transformer is excited
> at full mains voltage and near saturation.  Of course, this
> seems like it will reduce L and therefore drive the
> resonance higher!
> 
> What I might do is make up a cap bank that is 1.2 X larger
> than the 2 uF and power it up.  Then, measure the output
> voltage, and if it is within range just use it like that.
> If you want to get fancy, put it on a Variac and sweep the
> input voltage.  You will note a reverse slope, as input
> voltage rises through the range, output voltage will decline.
> 
> Jon

-- 
Chris Elmquist