Help identifying an early 80s (late 70s?) Intel (SBC?) board

[Lee Carter]

Hello everyone, thank you for allowing me to join.  I was going to use my first post to ask for assistance reading some files off 40+ year old MDS disks, but I've already been connected to Jon Hales and we're formulating a plan.

So, instead, I'm posting to see if anyone has any information about a couple of Intel boards I acquired in the early 80s when a student at Purdue - attached is a photo.

I *think* this may have been for a simple SBC based around an 8085 or possibly 8088.  It may have been associated with an Intel Application or Design Note, but if I had that, it was lost in a move long ago.

Does this look familiar to anyone?

- Lee

[craig andrews]

Doesn’t look familiar but from the markings, something for the MDS 800 if I were to hazard a guess.  

Looks like a switch to select between MDS and terminal. 

4X  RAM or ROM.

would have guessed a DB25 for serial but don’t see rs232 drivers or serial voltage rail so maybe the DB25 was just convenient connection cable

On Jun 11, 2022, at 1:36 PM, Lee Carter <68mg...@gmail.com> wrote:



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[Herb Johnson]

It would help incrementally if you photographed the back of the PC
board. So let's trace the lines we can see.

Rhe 25-pin connector looks like it supports a conventional serial line.
pins 4-5 are shorted, 1 and 7 are grounded. So check pins 2 and 3, they
are transmit and receive, and see where they go.

But it's likely they go to U8 and U9, which implies they are 1488 and
1489 RS-232 driver receiver chips. If so, see where those chips are
wired. The larger IC they are wired to, is likely a UART. Or, a I/O chip
of some sort.

The big 40 pin chips U2 and U3. Maybe one is a processor, an 8080 or
8085. Maybe one is a UART. There's a Y1, that's a crystal. See where
that goes; maybe to a processor, or maybe to U1, which is 18 pins. See
where U1 goes.

Meanwhile, there's three 28pin chips. best guess - ROM and RAM as they
seem to be wired in parallel. So most ROM and RAMs have common address
pins, data pins. Select something, say a 27128. Pins 11, 12, 13 are data
lines Q0, Q1, Q2. Where do they go on U2 U3 U4. which seem to be in
parallel? Pin 11 on U4, goes to pin 19 on U3, and ?. Pin 12 on U4, to
pin 21 on U3, to ?

What 40 pin IC has D0 on pin 19, D1 on on pin 21?
NOt the 8080, D0/D1 are 10 and 9.
Not the 8085, D0/D1 are 12 and 13.
NOt the 8250 UART.
NOt the 8088.

So: maybe U2 is a processor, and these lines go there. I can't see where
tthe "ROM/RAM data" lines go to on U2.

So my *guess* is that U2 is a processor of some sort, and U1 is a clock
driver of some sort (or a baud rate generator). Not sure about U3. The
28pin sockets are likely ROM and RAM, they are too regular. Maybe the
chip-select pins on those, go to U8 or U9 those might be gates for
memory control.

But you get the idea. It's like solving a Sudoku number puzzle. Things
you can readily determine, suggest other things. Follow the clues you
can to get more clues, in the way I described.

regards, Herb Johnson

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--
Herbert R. Johnson, New Jersey in the USA
http://www.retrotechnology.com OR .net
preserve, recover, restore 1970's computing
email: hjohnson AT retrotechnology DOT com
or try later herbjohnson AT comcast DOT net

[Herb Johnson]

On 6/11/2022 9:20 PM, Herb Johnson wrote:
>
> Select something, say a 27128. Pins 11, 12, 13 are data

> lines Q0, Q1, Q2. ... Pin 11 on U4, goes to pin 19 on U3, and ?.

> Pin 12 on U4, to pin 21 on U3, to ?
>
> What 40 pin IC has D0 on pin 19, D1 on on pin 21?

It's possible for design convenience, the design scrambled the data
lines. That's a bad practice but possible. The address lines like A0,
A1, A2, those are another check and less likely to be scrambled. So A0,
A1, A2 on the ROM/RAMs, to what pins on the two 40-pin sockets?

I'm a little scrambled myself, had a long day.

HErb

[Lee Carter]

Hi Herb, thanks for your replies!  I wasn't sure I'd get any interest, so didn't post the 'backside' photo... here it is.

As I mentioned, I'm pretty sure there was an Intel App or Design Note associated with it, just not sure (doubt?) I still have it, and certainly can't put my hands on it.  I vaguely recall the topic was a "minimal" or "5 chip design" 808X SBC.  The board (I actually have two) was definitely given to me by someone who worked for Intel, and he also gave me a bunch of (mostly un-silkscreened) chips - I believe the 'unmarked' nature of these chips was Intel's way of avoiding any commercial implications back at that time?  The Purdue EET Lab also had a bunch of SDK-85s - I remember hand-asembling and loading code for many "labs" back in the day.

I'm leaning toward this being 8085-based, since another board (and the reason for wanting to get files off those MDS disks) I'm working on is a 8085-based SBC designed by a fellow Purdue EE student - it's called an SCCS-85.  I've attached a pic of the one I build back in the day.  It's not a great pic, and the board has suffered from having a few components lifted for other projects and some neglect from being roughly boxed away over the years; but I'm planning on giving it some TLC and hoping to bring it back to life.  

As you can just about make out, the "large" chips used were the 8085, 8255 (40 pin), a 8251 (28 pin) and a 8253 (24 pin).  The unpopulated (40 pin) is a 8257 (optional on the SCCS).

Again, thanks everyone - esp. you Herb! - for the help so far solving this puzzle.  

- Lee

[Herb Johnson]

Seems you have the makings of a good story, about early days of Intel's
microprocessor development. And some artifacts of potential value,
certainly of interest. I'll explain.

In the early era, Intel wanted to introduce their microprocessors to
engineers and techs. And, to make the processors easier to use, Intel
developed support chips that provided ROM, RAM, serial, parallel
features. Consider: this was all *new*, there was no prior art - people
today forget "standards" like these functions are simply prior practices
that stuck. Intel was founded, to make semiconductor memories for
*minicomputers*; the rest just happened.

Also: Money was tight in the 1970's, and there were lots of small
manufacturers who used TTL and relay logic controls, or analog, or
mechanical. Also, colleges were not yet teaching microprocessors. They
didn't have money either. Engineers and professors had to BEG for even a
few dollars, from their management.

So to encourage experimenting, Intel produced very minimal kits wrapped
around a processor and some support chips. To the universities, they
offered just chip sets, or a small board with Intel processor and
support chips and a ROM. Even the 4004 was offered this way.

So what you may have, Lee, is one of those "university kits". Or, maybe
some one else designed a kit - but the Intel mark suggests it came from
Intel.

Your Plan A, is "homework". Look at docs and archived magazine articles
from Intel and see if your board appears in a photo. Check the Intel
data books for their kits. Of course you are asking around.

The "Plan B" I suggests, is that you reverse engineer the board you have
in hand. I suggested (frog-hopped you actually) the methodology. I may
have the details wrong but the method is correct. I've done it myself.
So can you. The more you can determine about this board, the easier your
"homework" will be. I'm saying: I won't work further on this. Your turn.
And: I've provided a starting narrative. If you use it, please give me
credit, thank you.

By the way:

>> gave me (mostly un-silkscreened) chips - I believe the

>> 'unmarked' nature of these chips was Intel's way of avoiding any
>> commercial implications back at that time?

Good guess, but no. As this was early days for these chips, Intel was
producing prototype runs of them. Or, these chips were simply
quality-control samples. Or, a batch was found to be marginal, so the
batch was rejected: some tech hand-sampled to find working chips. In any
event, these were chips not intended for customers.

Good news in a way for you. What you may have are rare chips! There's a
certain class of "chip collectors" who price these chips high, sometimes
very high. There's a taxonomy of chip-markings to identify such chips.
In Intel-markings, there's "CS" and "ES" for the kinds of samples these
are. More homework on the Web, will find "chipscape" Web pages and IC
identification, and of course discussion.

It's not my thing but it's unwise to solder a valuable chip on a board
and diminish its value, when a cheap chip will do. In this principle,
your board and chips are an artifact, which unassembled has a value as
I've suggested, to those interested in early Intel artifacts.

So the next steps are your call, Lee, as far as I'm concerned. The
puzzle will be solved, when you determine which chips fit this board,
and/or discover which Intel kit product this was. Or its origins
otherwise. AND: the nature of the chips you received with it.

These narratives, in my opinion, have to be told. If not, they will be
forgotten. And why work on vintage computers, show them off: if not to
restore our memories of them and preserve their work, design and
function, and history? That's my mission. If some people put excessive
values on particular things and artifacts, well, I won't argue, that
supports further interest, but collecting for value is not my prime
objective.

All in my opinion. Do as you wish, agree or not. But you asked for
"help", this is my interpretation of "help".

regards, Herb Johnson

> On Sun, 12 Jun 2022, 03:47 Herb Johnson, wrote:
>
> On 6/11/2022 9:20 PM, Herb Johnson wrote:
> >
> >  Select something, say a 27128. Pins 11, 12, 13 are data
> > lines Q0, Q1, Q2. ... Pin 11 on U4, goes to pin 19 on U3, and ?.
> > Pin 12 on U4, to pin 21 on U3, to ?
> >
> > What 40 pin IC has D0 on pin 19, D1 on on pin 21?
>
> It's possible for design convenience, the design scrambled the data
> lines. That's a bad practice but possible. The address lines like A0,
> A1, A2, those are another check and less likely to be scrambled.  So
> A0,
> A1, A2 on the ROM/RAMs, to what pins on the two 40-pin sockets?
>
> I'm a little scrambled myself, had a long day.
>
> HErb
>
> --
> Herbert R. Johnson, New Jersey in the USA

> http://www.retrotechnology.com <http://www.retrotechnology.com> OR .net

> preserve, recover, restore 1970's computing
> email: hjohnson AT retrotechnology DOT com
> or try later herbjohnson AT comcast DOT net
>

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[Lee Carter]

Sorry folks, I accidently dropped the group off this.

---------- Forwarded message ---------
From: Lee Carter <68mg...@gmail.com>
Date: Mon, 13 Jun 2022, 18:00
Subject: Re: intel-devsys Help identifying an early 80s (late 70s?) Intel (SBC?) board
To: Herb Johnson <hjoh...@retrotechnology.com>

Hi Herb, thank you for the priceless insight!   

While I'm not sure what I have classed as an Intel "University Kit", I am

as sure as I can be that it came from (at least someone who worked at)

Intel. 

Also, I have (re)discovered some pretty exciting info that should short

-circuit your suggested Plan A.  The board is called a "Vest Pocket

Computer (VPC)" and was based on an 8088.  How do I know this...

well, inspired by your insight, I did some digging through folders I

obviously squirrelled away when I moved into this house ~15 years ago,

and have found the documents I received with the boards! 

They included this:

I've scanned and attached the few sheets of paper that came with the

boards.  I also have a print-out of the source code for "Tiny Basic"

which the documentation refers to. 

My mission now is to work out whether or not it's possible to build and

get at least one of these running. It looks pretty straight-forward, except

for those 21821 "iRAM" chips.  I haven't been able to find much

(any!?) reference to them out there on the 'web.  Do you know anything

about them?

Re. my "(mostly un-silkscreened) chips", thank you for your insight

here as well.  I hadn't really thought about the value of them, but take

your point that I may be better off removing them and keeping them

safe.  I suppose the same applies to these:

As with the rest of my modest collection of "bits" from University

days, AFAIK, these were also given to me by my contact at Intel. 

Curious, though, that as far as I can gather, Intel's equivalent was

a "2116", yet these have been hand-inscribed (not by me) as "4116.

I suppose I better keep these safe as well.

When it comes to writing all this up, while I hear you and do not

question the value of doing that, I am fairly time-poor - still full time

employed with plenty of 'work' and family demands. I am meeting

up with Jon Hales tomorrow, so maybe he'll be able / willing to help

here! 

Before I go, I wanted to point to what few references I've found on

the 'web for my other board - the Purdue student-designed

"SCCS-85". It looks like the V3 version was used in a collaboration

with NASA on the "U.S. Department of Energy Flat-Plate Solar

Array Project". The following should get you to the few docs

that mention it:

- https://www.google.com/search?q=NASA+"SCCS-85"

All the best,

- Lee

[Lee Carter]

...and this one.  :-(

---------- Forwarded message ---------
From: Lee Carter <68mg...@gmail.com>
Date: Mon, 13 Jun 2022, 21:08
Subject: Re: intel-devsys Help identifying an early 80s (late 70s?) Intel (SBC?) board
To: Herb Johnson <hjoh...@retrotechnology.com>

Hi Herb!

I'm not far behind you... I also found that bitsavers PDF of Intel's iAPX88 book - decided to Google Intel and "Vest Pocket Computer" and viola!  So cool!

As you mentioned, however, I've also come to the conclusion those oddball 21821s are probably unobtanium... dang.  All I have are the two 'boards and the pages I scanned, plus the Tiny Basic listing and a sample program.  FYI, attached is a pic from the header section of the Tiny Basic source.  Definitely Intel - but I think we've established that now! ;-)

As for writing up / hosting, I don't have a web page, and probably won't until I can retire (hopefully in the next few years).  If you want to weave this little saga into your Intel history web presence, I'm fine with that and will be happy to contribute anything I can.  I'm not sure if you spotted, but the "Vest Pocket Computer" is mentioned in that iAPX88 book. It shows a block diagram, but I don't think there is a picture of a PCB.

Again, I really appreciate you sharing your knowledge -- your pointers and prompts were invaluable to the hunt.

Given the likely unobtanium nature of those 21821s, I doubt I'll get one of my VPC 'boards operational, but I might try keying in Tiny Basic, it's only ~1300 lines of Assembly.  Maybe I can get it running on one of  my SCCS-85s?  :-)

Do let me know if you want to put something up in your webspace.

All the best,

- Lee

On Mon, 13 Jun 2022, 20:35 Herb Johnson, <hjoh...@retrotechnology.com> wrote:

Great! And good work on your part, yields good results. and you did not
"short circuit my plan A", you *executed it*. Determined searching
yielded results. Mission accomplished to identify, but don't celebrate yet!

Maybe you have other chips you got with the board, than the RAM chips
you photographed? I hope so, because you'll need a 8755 compatible with
2K Tiny Basic for the 8088 - that's a Web search. And as you pointed
out, "21821" RAMs. Web search gave me: (PDF pages, see PDF page 234
following)

http://www.bitsavers.org/components/intel/8086/210200_iAPX88_Book_1981.pdf

The 21821 is apparently an Intel oddball: a 4K bytewide DRAM for
demultiplexing with the 8085 or 8088 bus. I could find nothing else
referencing that component. If you have some of these, you may have very
collectable chips!

The gold/purple chips you photographed, are 16 pin. They are hand-labled
"4116" which is a 16K by 1 DRAM. They may not be Intel, or if they are
they may be 2117's from Intel. At some small risk of damage, I'd use a
DVM on "diode test" and compare one of these chips to a known 4116 and
do "diode testing" on selected pairs of pins to A/B compare, to identify
voltage-drops and polarities. without detailing: put the black negative
DVM probe on the ground pin, and look with the red positive probe at
each pin. See if the same voltage-drops occur pin for pin with a 2117.

http://minuszerodegrees.net/memory/4116.htm

And now, you have the makings of a Web page, at least about the Intel
board and chips. To inform others and to have others inform you. It's a
worthy topic, an unusual item. I don't know what chips you have for that
board, you photographed those DRAMs instead.

And for me, it showcases some reverse-engineering. I was close with my
guesses and the methods were right.

Is a Web page something you can do or wish to do? Or if you wish, since
I worked hard on this, I can host the Web page with the correspondence
you and I created and your photos. If I do this, I will show your name
but not your email address; people contacting me will have their email
referred to you. That's my 20th century way of handling privacy. If you
have a Web site, instead I'll link to your Web site.

Let me know, for the work I did I'd like to see it online. And you now
have what you need, to decide what to do with the 8088 board and any
chips you have with it. They have a value as a set, unassembled and
documented. I don't know the value of your unmarked likely-DRAMS, I'm
not a chip collector.

regards, Herb Johnson

On 6/13/2022 1:00 PM, Lee Carter wrote:
> Hi Herb, thank you for the priceless insight!
>
> While I'm not sure what I have classed as an Intel "University Kit", I am
> as sure as I can be that it came from (at least someone who worked at)
> Intel.
>
> Also, I have (re)discovered some pretty exciting info that should short
> -circuit your suggested Plan A.  The board is called a "Vest Pocket
> Computer (VPC)" and was based on an 8088.  How do I know this...
> well, inspired by your insight, I did some digging through folders I
> obviously squirrelled away when I moved into this house ~15 years ago,

> and *have found the documents I received with the boards! *
>
> They included this:

>
> Vest Pocket Computer.PNG
> I've scanned and attached the few sheets of paper that came with the
> boards.  I also have a print-out of the source code for "Tiny Basic"
> which the documentation refers to.
>
> My mission now is to work out whether or not it's possible to build and
> get at least one of these running. It looks pretty straight-forward, except
> for those 21821 "iRAM" chips.  I haven't been able to find much
> (any!?) reference to them out there on the 'web.  Do you know anything
> about them?
>
> Re. my "(mostly un-silkscreened) chips", thank you for your insight
> here as well.  I hadn't really thought about the value of them, but take
> your point that I may be better off removing them and keeping them
> safe.  I suppose the same applies to these:
>

> 20220613_131025.jpg
>
> As with the rest of my modest collection of "bits" from University
> days, AFAIK, these were also given to me by my contact at Intel.
> Curious, though, that as far as I can gather, Intel's equivalent was
> a "2116", yet these have been hand-inscribed (not by me) as "4116.
> I suppose I better keep these safe as well.
>
> When it comes to writing all this up, while I hear you and do not
> question the value of doing that, I am fairly time-poor - still full time
> employed with plenty of 'work' and family demands. I am meeting
> up with Jon Hales tomorrow, so maybe he'll be able / willing to help
> here!
>
> Before I go, I wanted to point to what few references I've found on
> the 'web for my other board - the Purdue student-designed
> "SCCS-85". It looks like the V3 version was used in a collaboration
> with NASA on the "U.S. Department of Energy Flat-Plate Solar
> Array Project". The following should get you to the few docs
> that mention it:
> - https://www.google.com/search?q=NASA+
> <https://www.google.com/search?q=NASA+>"SCCS-85"
>
> All the best,
> - Lee

[Lee Carter]

:-|

---------- Forwarded message ---------
From: Lee Carter <68mg...@gmail.com>
Date: Tue, 14 Jun 2022, 06:09
Subject: Re: intel-devsys Help identifying an early 80s (late 70s?) Intel (SBC?) board
To: Herb Johnson <hjoh...@retrotechnology.com>

Hi Herb,

Your tip re. the Intel Insite Library landed me here :

http://www.bitsavers.org/pdf/intel/insite/1983_Insite_Users_Program_Library_Catalog.pdf

...and in it, I found the attached. So... it looks like "AE13" is what I need to hunt for. :-)

Re. my listing, I'm happy to scan it in.  Unfortunately, it appears to have been printed on pin fed "lined" paper, so OCR'ing it may be a challenge.  Still, it might be a more efficient starting point.

One other thing, I'm wondering if those "21821" chips may have been a preliminary or prototype number, I do see a reference to Intel "iRAM" in this:

http://www.bitsavers.org/components/intel/_dataBooks/1984_Intel_Memory_Components_Handbook.pdf

It references a 2186A 8kx8 chip - which is a 28 pin package.  I haven't compared that chip's pinout with the VPC diagrams, but it is curious.

Lastly, I need to apologise in advance if I go a bit quiet... work and life demands are rising. I'm in no way any less enthusiastic for this hunt we're on... just juggling!  ;-)

Cheers, Lee

On Mon, 13 Jun 2022, 23:57 Herb Johnson, <hjoh...@retrotechnology.com> wrote:

> but the "Vest Pocket Computer" is mentioned in that iAPX88 book. 

Right. That provides a schematic.

I can whip up a Web page, I've got photos and our discussion and the
documents you provided. See if you can scan that Tiny Basic listing. The
scans might be smaller if you scan 8-bit (grey scale) and not color. It
may prove simpler to hand-type it, than to OCR it, or to extract it from
the Web.

Your listing cites: Bill Righter MPD Applications Lab Intel;
John Bartlett Intel Sales office, Chelmsford MA
Version 2.1 Mar 20 1981

as far as Tiny BASIC for the 8085, that exists already, at least an 8080
version. My friend Jon Chapman probably has an 8085 version that uses
the bit in/out pins of the 8085; he has a nice single-board for that.

Following the clues: From the Intel INSITE library, 1983 edition:

BF9, INTERPRETER: 8086/8088 TINY BASIC
Submitted by: Bob Glossman, Intel Corporation
Abstract: This program is a very small (less than 1 K of code) BASIC
interpreter allowing 26 variables and one array.
Hardware Required: Intellec, 8086-based; iSBC 86
Software Required: ISIS-II
Required: RAM/48K; BLOCKS/1040
Programming Language: Assembly. Assembler/Compiler: MCS-86 Assembler, X084
Media Availability (Price Code): DISKETTE (D), SRC, OBJ, LST; SOURCE
LISTING (L); DOCUMENTATION

https://www.pcorner.com/list/BASIC/TBASIC.ZIP/INFO/

The present version of TINY BASIC is based on Li-Chen Wang's
Palo Alto 8080 TINY BASIC as published in the May 1976 issue of DR.
DOBB'S JOURNAL. It has been optimized for the
8086 and it takes advantage of the hardware multiply and divide that
the 8086 affords. due to Michael E. Sullivan,  Haddonfield, NJ, 08033.

That's all I found. So your listing, may be a thing. Unless, one of our
colleagues here, has enough of the early Intel INSITE library to include
the BF9 file.

As far as simple 8088 computer kits, I don't see any. There's would-be
IBM-XT type boards, that's too much. A $150 kit with hex keyboard, has
features not required. In the Intel manual exerpt I attached, there's an
8088 demultiplexed schematic that uses ordinary components. That's
probably as good as anything available. But I didn't scour the Web for
every github or hackaday project or other obscurities. Of course, a
Multibus 8086 or 8088 CPU would work too. ;)

regards, Herb

[Lee Carter]

Last one (I hope).

---------- Forwarded message ---------
From: Lee Carter <68mg...@gmail.com>
Date: Tue, 14 Jun 2022, 06:31
Subject: Re: intel-devsys Help identifying an early 80s (late 70s?) Intel (SBC?) board
To: Herb Johnson <hjoh...@retrotechnology.com>

Tantalisingly referenced here [DEMO: iAPX-88] -

https://www.intel-vintage.info/intelsofware.htm

But no link.  😞

[Lee Carter]

So... checked the pinouts.  2186A is nothing like those 21821s.  I guess the latter never made it into the real world.  Oh well.  Perhaps someone here has a line on that "AE13" DEMO?

Thx all, Lee

[Lee Carter]

Unfortunately, I doubt that.  If you check the schematics, you'll see the "21821"s use all 16 Address lines, multiplexed(?) with the Data lines.  I believe Intel did this so that they could be "direct attached" to a 8086 / 8088 with little / no interface circuitry.

On Tue, 14 Jun 2022, 08:47 forjack842, <forja...@aol.com> wrote:

Just for a chance. Those RAM chips may pin match later chips by others. Memory chips tend to follow the same pin outs. I'm guessing those are static and not dynamic. If you know size like 2048x8 DIP 16 a search of memory chip history may uncover gold. That chip design was surely used later as a marketable device under a different number

Sent via the Samsung Galaxy A11, an AT&T 4G LTE smartphone

[Herb Johnson]

Summary on the "Vest Pocket Computer" 8088 from Intel:

So, Lee Carter says he'll scan out the intel 8088 tiny basic listing (on
paper) and send it to me (and presumably this list). I've agreed to make
a Web page about his 8088 board based on his docs and docs found so far
on the Web. It's one of many university/demo processor boards/kits Intel
provided in the era. "Vest Pocket Computer (VPC)"

It's an odd one because it uses chips like the 8755 with mask ROM and a
RAM that accepts multiplexed address/data, Intel 21821. He has boards
(two duplicate boards) but no chips, so this won't be built.

Lee and I found two Intel Insite library program descriptions that may
be relevant: anyone have these programs?

AE13, DEMO, iAPX-88
four programs Tiny Monitor, Tiny BASIC, 2K & 4K Chess.

BF9, INTERPRETER: 8086/8088 TINY BASIC
Submitted by: Bob Glossman, Intel Corporation

1K Basic interpreter

It had some use in a NASA-funded university project, from which I
extracted the User Manual. an iAPX88 1981 Intel manual has the schematic
and brief description. So, it's an example of what was done in the era
to promote these new microprocessors and family chips.

Regards, Herb

--

[Eric Smith]

On Mon, Jun 13, 2022 at 11:37 PM Lee Carter <68mg...@gmail.com> wrote:

The board is called a "Vest Pocket

Computer (VPC)" and was based on an 8088.

The VPC design is described in the 1981 iAPX 88 Book (210200), starting on page 4-3. The schematic is present, along with a description.

The 21821 is described as a 4Kbyte RAM designed to work directly on the 8088/8086/8085 multiplexed bus. They don't say, since they're using it on an 8088, but based on the schematic, the 21821 worked with either 8-bit or 16-bit data width, with pin 27 (BHE) grounded for 8-bit width. It also appears that it was a pseudo-static device, as pin 2 appears to control the refresh mode.

The terminal interface uses GPIO pins from the 8755A. They use a 74LS14 as both the RS-23 driver and receiver, and in the schematic as shown, the driver cannot possibly work well, for reasons they explain in the immediately preceding design example which uses the RS-232 receive to provide negative voltage for transmit.

[Eric Smith]

On Tue, Jun 14, 2022 at 10:09 AM Herb Johnson <hjoh...@retrotechnology.com> wrote:

It's an odd one because it uses chips like the 8755 with mask ROM

The 8755 is an EPROM-based part. The masked-ROM equivalent is the 8355.

[Lee Carter]

Hi everyone, sorry for the slow response, work's pretty demanding this week!

@Herb, thank you for pulling this together.   

I've not had the chance to scan my Tiny Basic source listing, but I DID have time to connect with Jon, who very kindly used his kryoflux rig to read in a couple of 40yr old 8" disks I have from way back then.  Tantalisingly, one of the disks had a file called tinybs.88.  I've attached it to this email.

It's a strange file, it seems to have multiple sections, some look like hex dump, the others source code.  But it looks like the latter may have been duplicated?  The disk was definitely from a MDS.  Does anyone know anything about this ".88" format?  Was it some kind of "contatenation" file?

Anyway, some of the header text does refer to the Intel "5 chip board", but I don't believe this is my VPC.  Curious that I do have the disk... just not sure the disk and my board are connected.  Also, the TB source in this file does not match the hardcopy listing I have.  Interested to see if anyone is familiar with that ".88" file format.

Lastly, @Herb, small correction to your summary below.  The VPC was not used in any Purdue-involved NASA projects, that was the other boards I have - the "SCCS-85" ones.

[Lee Carter]

Update here as well... those "purple/gold" chips *are* 4116s - Jon also tested those.  He also looked underneath them (I didn't think to do that! 🙄) and found they are marked MKM4116 - so they are Mostek, not Intel.  Good news is 6 test good, 1 tests good but has a broken pin, but the 8th is duff.  😞

Sadly, I have NO recollection of where I got them... probably back in the early 80s when at Uni... 

[Herb Johnson]

On 6/15/2022 2:20 PM, Lee Carter wrote:
> Lastly, @Herb, small correction to your summary below.  The VPC was not
> used in any Purdue-involved NASA projects, that was the other boards I
> have - the "SCCS-85" ones.

My error, in attributing the JPL/NASA project report to your 8088 card.
The document had support documents for your SCCS-85 card. The iAPX-88
manual had a description and schematic for your 8088 card. Both cards
are examples from the era as I described.

> I've not had the chance to scan my Tiny Basic source listing, but I DID have time to connect with Jon, who very kindly used his kryoflux rig to read in a couple of 40yr old 8" disks I have from way back then. Tantalisingly, one of the disks had a file called tinybs.88. I've attached it to this email.
>
> It's a strange file, it seems to have multiple sections, some look like hex dump, the others source code. But it looks like the latter may have been duplicated? The disk was definitely from a MDS. Does anyone know anything about this ".88" format? Was it some kind of "contatenation" file?
>
> Anyway, some of the header text does refer to the Intel "5 chip board", but I don't believe this is my VPC. Curious that I do have the disk... just not sure the disk and my board are connected. Also, the TB source in this file does not match the hardcopy listing I have. Interested to see if anyone is familiar with that ".88" file format.

My examination of the file, suggests to me it's fragments of several
files. He probably grabbed sectors and put them in a file, something
quick and preliminary. It's not "in an .88 file format", Lee - it's just
a file of files.

Extracting out the pieces, there's a list of files relative to a
"TBASIC"; a brief description TBASIC; and some Intel hex records
and sources which I'm guessing represent the files. Inspection of the
fragment shows two copies of a "Tiny Basic for the 8086". Are they
identical? No idea.

The code looks familiar from my previous rooting around: here's a bit of
header from the recovered fragment.

; TINY BASIC FOR THE 8086
; VERSION 1.0
; @COPYLEFT
; ALL WRONGS RESERVED

It's likely an old translation of 8080 Tiny BASIC by LI-CHEN WANG (Dr.
Dobbs Journal), into 8086 mnemonics. various persons worked on that
translation and revisions. A search of the Web finds various versions of
the 8086 Tiny BASIC.

https://www.pcorner.com/list/BASIC/TBASIC.ZIP/INFO/

My *guess* is that the BASIC provided by Intel for the Intel 8088
board was some other code. That code is likely to be in the Intel
Insite library in one of the two Insite products mentioned by Lee and
myself.

Lee, your listing may be the only hope.

Lee's reference to the "Intel 5 chip board", may be a reference to the
OTHER of the two 8088 examples in the iAPX-88 book. One is the VPC. The
other Intel calls the "Multiplexed system" which uses five chips,
including a 8755A to hold 2K of program and provide I/O including
bit-spit serial apparently. This latter system uses chips one can get
today.

regards, Herb

[Lee Carter]

Hi Herb,

My examination of the file, suggests to me it's fragments of several files. He probably grabbed sectors and put them in a file, something quick and preliminary. It's not "in an .88 file format", Lee - it's just a file of files.

That was my impression as well, except, I have a hardcopy DIR listing from back when the disk was "new" and it ONLY shows two files, both with ".88" extension.  One is the 'tinybs.88' and the other 'mumon.88'.  Also, this disk read clean with Jon's kryo-rig, and the recreated output has only these two files (plus the hidden "ISIS" catalog / directory files) nothing else.  Lastly, all the other disks Jon imaged are the same - the resulting contents / files map to the hardcopy listings I made 40yrs ago on a real MDS.  I therefore don't think we can just dismiss these '.88' files as being created by Jon's (very thorough btw) process.

Regardless, I think you are right.  Whatever this version of "Tiny Basic" was for, it does appear to be derived from that other TB (Copyleft) version.

Back to my TB listing.  Although slightly obscured by the 'lined paper, I will get it scanned in and post it here.

[Bill Beech (NJ7P)]

Guys,

I used Mumon88 back in the day when I first got an MPX-16 Clone PC board running.  Was that an Intel product?

Thanks!

Bill

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[Lee Carter]

Wow, neat.  I can't remember ever actually using MuMon, but I've attached the file Jon pulled off one of my disks.  

Hope it's of use / interest.

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[Herb Johnson]

So, like the Tiny BASIC ".88" file, this mumon.88 file has a set of
various files and a brief directory document. By simple inspection,
there's four hex-dump-like files, two pairs of apparently two programs.
There's an assembly source file or two; there's an assembled listing
file. They seem to be about, or related to, a ROM monitor. So that's
point one.

I can provide a ZIP of the extracted files, but anyone with a text
editor can produce the same result in 15 minutes from the just-posted
file. There's no binary (that I noticed) in the files.

Point two. Lee Carter made the point, that his disks from 40 years ago,
all have sets of files using this scheme with the .88 extension. He
asked in effect, "was this a thing?". I said based on one example, like
"probably not". But with many examples, maybe it was some kind of thing.
So was this a thing under ISIS from Intel, to pack and unpack files? To
save precious diskette space, for convenience. Of was this made-up at
the site Lee Carter worked at?

There were such utilities, in CP/M as I recall. But my guess STILL is,
the ".88" extension, is not nomenclature for "this is a compressed set
of files"; but arbitrary nomenclature for "this is a set of files for an
8088". Whenever Lee, or Jon Hales, releases the other recovered files,
there will be more evidence.

But "content is king", however it's packaged. It's always good to
recover more files from Intel/ISIS diskettes.

regards, Herb

On 6/16/2022 2:04 PM, Lee Carter wrote:
> Wow, neat.  I can't remember ever actually using MuMon, but I've
> attached the file Jon pulled off one of my disks.
>
> Hope it's of use / interest.
>

> On Thu, 16 Jun 2022, 18:38 Bill Beech (NJ7P), wrote:
>
> Guys,
>
> I used Mumon88 back in the day when I first got an MPX-16 Clone PC
> board running.  Was that an Intel product?
>

> On 6/15/2022 11:48 PM, Lee Carter wrote:
>>

>> ...I have a hardcopy DIR listing from back when
>> the [TBASIC] disk was "new" and it ONLY shows two

>> files, both with ".88" extension.  One is the 'tinybs.88' and the
>> other 'mumon.88'.  Also, this disk read clean with Jon's kryo-rig,
>> and the recreated output has only these two files (plus the hidden
>> "ISIS" catalog / directory files) nothing else.


Lastly, all the
>> other disks Jon imaged are the same - the resulting contents /
>> files map to the hardcopy listings I made 40yrs ago on a real
>> MDS.  I therefore don't think we can just dismiss these '.88'
>> files as being created by Jon's (very thorough btw) process.

[Lee Carter]

Only one of my disks (I have 4) has these .88 files.  The other three have discrete files.  On this disk, there are just 2 files - tinybs.88 and mumon.88.  It us curious that the tinybs file seems to start with what appears to be a directory list of files, whereas the mumon one seems to start with a hex dump/listing.

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[Herb Johnson]

On 6/16/2022 1:37 PM, Bill Beech (NJ7P) wrote:
>
> I used Mumon88 back in the day when I first got an MPX-16 Clone PC board
> running.  Was that an Intel product?

Intel-iAPX88 Book 1981

http://www.bitsavers.org/components/intel/8086/210200_iAPX88_Book_1981.pdf

iAPX 88=BASED S-100 BUS SYSTEM [OCR so spelling problems]
page 4-12

One very popular standard for microcompu-
ter systems is the SI 00 Bus. This appHcation
example describes an SI 00 system which uses
the iAPX 88 to implement a high perfor-
mance system which has many other benefits.

First, an iAPX 88-based SlOO system is easy
to implement, because the CPU interface is
very similar to the CPUs for which the
standard SlOO was originally designed. For
example, the hardware of an 8083-based
SlOO CPU card is very similar to this system.

Secondly, because this SlOO system is using
an iAPX 88 CPU, standard SlOO memory,
I/O, peripherals, and other cards, can take
advantage of the powerful iAPX 88 features
to greatly enhance the capabilities of existing
S 100 systems based on the 8080, Z80 or other
8-bit CPU's.

Another point is that, along with higher
performance, the system also has the advant-
age of the greatly relaxed iAPX 88 bus to
accoitimodate slower memory, I/O, and
peripheral cards without the perfomaance ,
degradation of wait states.

The bus also directly supports the iAPX
88's 1 Megabyte memory address space.

As shown in the block diagram in Figure 4-6,
the system has 3K bytes of EPROM (three
2708's), IK of ROM (two 2114s), fully
buffered busses and demultiplexed address
bus. The control and status busses have been
decoded to.provide compatible signals for the
S-lOO bus.

1/ O, peripherals and additional memory are
assumed to be on the other standard SlOO
cards in the system. A detailed schematic is
shown in Figure 4-7.

PC board and software for this system are
available from Microfuture. The boards
are called the CP88, and the monitor
software the muMon/88.

Note 1: Microfuture, PO Box 5951, San Jose CA
95150.

[Herb Johnson]

"once is happenstance, twice is coincidence, three times is enemy
action". - attributed to Ian Flemming in "Goldfinger".

On 6/16/2022 2:59 PM, Lee Carter wrote:
> Only one of my disks (I have 4) has these .88 files.  The other three
> have discrete files.  On this disk, there are just 2 files - tinybs.88
> and mumon.88.  It us curious that the tinybs file seems to start with
> what appears to be a directory list of files, whereas the mumon one
> seems to start with a hex dump/listing.
>
> On Thu, 16 Jun 2022, 19:50 Herb Johnson,

> Point two. Lee Carter made the point, that his disks from 40 years ago,
> all have sets of files using this scheme with the .88 extension. He
> asked in effect, "was this a thing?". I said based on one example, like
> "probably not". But with many examples, maybe it was some kind of
> thing.

--

[Bill Beech (NJ7P)]

I have seen the .86 files and now the .88 file.  It appears to be an ASCII hex format to load the actual monitor.  Neat!  I will have to find my MuMon source code and see how they compare.

Thanks!

Bill

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[Lee Carter]

In case this is easier to access...

- https://app.box.com/s/in75rdwnbil2fui8nnwd5rtzq42jxy28

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[Bill Beech (NJ7P)]

This is all very interesting.  So MicroFuture was the source of the
MuMon Monitor.

I suspect you could use a pair of LS373s to demux the address and data
lines from some static RAMs like 6116, 6264, 64256 on an adapter board
to replace the 21821 RAMs.

Thanks!

Bill

[Bill Beech (NJ7P)]

Just for grins, guys.

Bill

On 6/16/2022 11:57 AM, Herb Johnson wrote:

[Lee Carter]

That thought (at least in concept) had crossed my mind.  Unfortunately, I don't have the skills to make up such a circuit.  I do, however, know someone who might at least be able to recreate the VPC circuit board, so that experimenting could be done without damaging my two boards.  Worth considering. 😀

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[Bill Beech (NJ7P)]

Looking at the listing, though it says it is for an SBC 88/25, the I/O
is for a PC.  But the source is solid.

I disassembled this monitor in 1983 or so and used it on my MicroMint
MPX-16 motherboard.  It was fun because the MPX-16 was close, but no
cigar, to an IBM PC.  Lots of issues to work out to get it to run PCDOS.

Bill

[Bill Beech (NJ7P)]

Ah, here is a copy by MicroFuture for CP/M-86!

Bill

[Herb Johnson]

So, there's many variations of mumon88 in play now:

On 6/16/2022 5:08 PM, Bill Beech (NJ7P) wrote:
> Ah, here is a copy by MicroFuture for CP/M-86!
>
> Bill

attached: mumon88.a86 - Bill, where did you get this?

; * m u M o n / 8 8 *
; * A system monitor for 8088 or 8086 microprocessors *
; * written Q2 1980 - revision 1.1 *
; * copyright 1980 Microfuture *
; *******************************************************
;
; This code is written for assembly by ASM86.
;
SIGNON DB 'muMon/88 version 1.2'
DB CR,LF
DB '(c) Microfuture 198','0'+80H

earlier:

> On 6/16/2022 4:49 PM, Bill Beech (NJ7P) wrote

:> Just for grins, guys.
>>
>> Bill

Beech's MON88.LST, attached:

Microsoft (R) Macro Assembler Version 4.00 4/12/16 22:58:31
SIGNON DB CR,LF,'Mon88 version 1.','1'+80H

Carter's mumon88 ".lst" extracted from mumon.88:

muMon/88 DEVELOPMENT AND EVALUATION MONITOR XMACRO-86 3.36
copyright 1980 Microfuture

F447 6D 75 4D 6F SIGNON: DB 'muMon/88 version 1.2'

...and, Bill Beech's disassembly years ago:

http://www.nj7p.org/Computers/Software/Monitors/work/mon88_1_0a.7z

regards, Herb

[Bill Beech (NJ7P)]

Herb,

I am not really sure.  It was in the archive I had the SBC 88/25 version
in, which is really a DOS version. I have more software than I can
remember....

Bill

[Lee Carter]

>  I have more software than I can remember....

You wouldn't happen to have a copy of any of the Intel Insite Library from 1983 by chance?

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[Lee Carter]

Update on scanning my Tiny Basic for the VPC listing...  

I had a look at this last night and decided I need to set aside some time.  The listing is a 40yr old photocopy, so not the best quality.  Also, sadly, it is single page copies from a continuous fan-fold printout, and so there are several pages where one to three (at least) lines of code that landed on the folds were blurred / missing.  

I'll need to fiddle with my scanner settings to see if I can get a decent scan, but we're probably going to need to hope this "special" Tiny Basic version for VPC does not deviate too far from the others we've located.

There is hope, but also challenge.  Stay tuned.  :-)

[Lee Carter]

Well... while doing a little over my first cup of coffee research this AM, I was perusing the Wikipedia Intel page - https://en.m.wikipedia.org/wiki/Intel - and found this mention "Intel opened its first international manufacturing facility in 1972, in Malaysia, which would host multiple Intel operations, before opening assembly facilities and semiconductor plants in Singapore and Jerusalem in the early 1980s".

I wonder... maybe Intel was fab'ing chips for Mostek?  Maybe these were given to me by the same guy I knew at Intel?  Curious, but unless someone can deep-dive my aging grey matter, we'll (I'll) probably never know.  Oh well.  

[Lee Carter]

He he... perhaps it was the other way 'round... 🤔

- https://en.m.wikipedia.org/wiki/Mostek

"Mostek's DRAM legacy is exemplified in the MK4116, MK4164 and MK41256, each of which were successfully cloned by competitors, both USA-based and overseas-based."

Fascinating times...

[Lee Carter]

Here is a first attempt.  

A quick comparison to my other tinybs.88 shows that the opening section of this TB is significantly different, and that even some of the 'main' sections - at least the comment blocks - are also significantly different.

I did spot - one piece of positive news - is that the section with a missing line between page 9 & 10 of my listing does appear in the tinybs.88 source, so at least that one can be recovered.

In absence of anyone locating that "AE13" folder from the 1983 Insite Library, I guess I'll need to start keying this in and hopefully filling in any missing bits from the tinybs.88 listing.  

[Herb Johnson]

1) To save your time, you might only key-in the lines that appear blurry
on the PDF you just provided. Of course identify the location of those
lines and include a line one can recognize in the PDF.

2) If i assume you have joined the intel-devsys group, I don't have to
include your email address in my posted reply. That save you double
emails on replies like this. Let me know accordingly or of course post
accordingly.

It's good to see this material you are providing. It's paying dividends
by updating or confirming other material, like Bill Beech's prior
disassembly of that 8088 monitor.

Regards Herb

On 6/17/2022 6:15 AM, Lee Carter wrote:
> Here is a first attempt.
>
> A quick comparison to my other tinybs.88 shows that the opening section
> of this TB is significantly different, and that even some of the 'main'
> sections - at least the comment blocks - are also significantly different.
>
> I did spot - one piece of positive news - is that the section with a
> missing line between page 9 & 10 of my listing does appear in the
> tinybs.88 source, so at least that one can be recovered.
>
> In absence of anyone locating that "AE13" folder from the 1983 Insite
> Library, I guess I'll need to start keying this in and hopefully filling
> in any missing bits from the tinybs.88 listing.
>

> On Fri, Jun 17, 2022 at 7:00 AM Lee Carter wrote:
>
> Update on scanning my Tiny Basic for the VPC listing...
>

> fan-fold printout, and so there are several pages where one to three
> (at least) lines of code that landed on the folds were blurred /
> missing.

[Herb Johnson]

On 6/17/2022 11:01 AM, Herb Johnson wrote:
> 1) To save your time, you might only key-in the lines that appear blurry
> on the PDF you just provided. Of course identify the location of those
> lines and include a line one can recognize in the PDF.

Of course, the actual listing has line numbers, to identify each line.
Also for redundancy, the listing provides opcodes and data bytes to
confirm the assembly source content.

and: the code seems similar to TBASIC files recently posted, extracted
from the "tinybs.88" file-set. The hex-records in that file-set, seem to
match the hex-code content in the PDF. For instance: the hex record
early in the tinybs.88 file

:100000004C495354F69052554EF6644E4557F654AB

corresponds to the PDF image section (hand typing)

0189 4c495354 302 tab: db 'LIST'

in the 'TABLES' section on the 4th page of the PDF.

Please note "seems". I glanced at these documents, not a close examination.

So reconstruction of the PDF listing is a tedious matter of editing
those tinybs.88 fragments into a single complete (and maybe slightly
different) source based on the scanned listing. It's up to whomever
performs the work. So the PDF listing "glues" the hex records and the
sources together and maybe provides additional information such as I/O
configuration. Who knows until it's done?

Hopefully this PDF and the tinybs.88 are sufficient to "recover" the
Tiny BASIC likely provided by Intel with this particular 8088 board
product. The physical evidence is: proximity of the paper listing, the
diskette content of disks from an INtel development system, and the 8088
circuit boards; all owned by one person who obtained them decades ago.

It's the nature of these "finds" to be slight variations of each other.
They are fragments from someone's development or use; not some complete
& original distribution. already, the other fragments of this TBASIC are
variations due to adapting for different assemblers under different
OS's. The PDF paper listing was assembled under MCS-86 Macro Assembler
V2.1. (There's no listing in the tinybs.88 file, just sources and hex
records.)

regards, Herb

[Lee Carter]

So reconstruction of the PDF listing is a tedious matter of editing
those tinybs.88 fragments into a single complete (and maybe slightly
different) source based on the scanned listing. It's up to whomever
performs the work. So the PDF listing "glues" the hex records and the
sources together and maybe provides additional information such as I/O
configuration. Who knows until it's done?

Indeed. But I think it will be worth the effort - even if it's unlikely I'll be able to make one of my VPCs operational.

Oh, and yes, I have joined the intel-devsys group.

Cheers, Lee

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[Bill Beech (NJ7P)]

Lee,

I have several programs out on the Google drive.  I just gave you access.

https://drive.google.com/drive/folders/147raTizgJ_T5oUZQLDu2UiusVrE4MPui

Bill

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[Lee Carter]

Thanks!

If you want to create a "Lee" folder, I'll be happy to upload what I have.  I do plan to attempt the recreation of Tiny Basic for the VPC, just have the usual work / family demands that might slow things down.  😉

I'll do some digging this weekend to see what I can find.

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[Bill Beech (NJ7P)]

LeeC folder was just created.

Bill

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[mark.p...@btinternet.com]

Le

I looked at the tiny basic source in tinybs.88 and most of it matched your printout.

I have modified the code so accordingly. Excepting my errors hopefully it should match your printout. I have saved the files your area on Bills Google Drive. I include the source and an assembly listing.

PS. I did leave a couple of comments in from the original tinybs.88 version, but the code should be the same.

 

Note If you need to use an old asm86 assembler, otherwise it flags errors about segment MEMORY not being defined and a NAME definition missing. Both harmless but annoying

Mark

 

 

From: intel-...@googlegroups.com <intel-...@googlegroups.com> On Behalf Of Lee Carter
Sent: 17 June 2022 18:24
To: intel-...@googlegroups.com
Subject: Re: intel-devsys Help identifying an early 80s (late 70s?) Intel (SBC?) board

 

Thanks!

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[Lee Carter]

Wow Mark, that's amazing!  Thank you.

TBH, I'm not sure yet what I'll do with it... as we've discovered, those 21821s on the VPC 'boards from Intel are unobtanium / or never made it to market.  Given an 8755 does have some RAM onboard, I wonder if it would at least "boot"?  🤔

To view this discussion on the web visit https://groups.google.com/d/msgid/intel-devsys/006601d88278%2410186430%2430492c90%24%40btinternet.com.

[Bill Beech (NJ7P)]

Looks like you need an adapter board with one 74LS373 and 2 6264 RAM chips to replace all 4 of the 21821s. You should be able to get the vest pocket board completely working.

Bill

To view this discussion on the web visit https://groups.google.com/d/msgid/intel-devsys/CAJt1R0MTaAKNx1WV%2BhpiHcpGw65hgx5aD5X9y%2B1%3DErBFu5TucA%40mail.gmail.com.

[Herb Johnson]

On 6/17/2022 4:13 PM, Bill Beech (NJ7P) wrote:
> Looks like you need an adapter board with one 74LS373 and 2 6264 RAM
> chips to replace all 4 of the 21821s. You should be able to get the vest

> pocket board completely working. - Bill

... and a 8755 programmed with a monitor or TBASIC (2K ROM). Who
programs Lee's 8755?

The interesting thing about the VPC is why it CAN'T be built, not how it
can. My opinion.

Or: build a 5-chip 8088 board with conventional ROM and RAM and an 8255.
My glance suggests the 8755 is an 8255 with ROM. - Herb

[Jack Mcmullen]

Tiny Mods and Errors Fixes attached

-----Original Message-----
From: Herb Johnson <hjoh...@retrotechnology.com>
To: intel-...@googlegroups.com
Sent: Fri, Jun 17, 2022 1:43 pm
Subject: Re: intel-devsys Help identifying an early 80s (late 70s?) Intel (SBC?) board

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[forjack842]

Did my suggestions make it thru for an adapter board yesterday???

Sent via the Samsung Galaxy A11, an AT&T 4G LTE smartphone

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[forjack842]

Stack and a i/o buff the 8755 ram should be enough to boot

Sent via the Samsung Galaxy A11, an AT&T 4G LTE smartphone

-------- Original message --------

From: "Bill Beech (NJ7P)" <nj...@nj7p.info>

Date: 6/17/22 1:14 PM (GMT-08:00)

To view this discussion on the web visit https://groups.google.com/d/msgid/intel-devsys/d73cfd16-f744-397f-686b-6b9091d468cf%40nj7p.info.

[Herb Johnson]

Good catch, Jack McMullen

Mark Ogden, if you make the fixes, consider also added the Intel Hex
file to the listing and ASM files. It's nice to make a binary at some
point. Binaries can be compared to other binaries from other assemblies
and fixes. There's also in the tinyb88 file, some Intel hex records.
Those too could be turne to binary for comparison.

Regards Herb

On 6/17/2022 6:04 PM, 'Jack Mcmullen' via intel-devsys wrote:
> Tiny Mods and Errors Fixes attached
>
>

On 6/17/2022 6:10 PM, 'forjack842' via intel-devsys wrote:
>> Stack and a i/o buff the 8755 ram should be enough to boot

>> Did my suggestions make it thru for an adapter board yesterday???

I don't think "forjack842" messages appeared yesterday. Google Groups
has our list on-the-web. I dunno, make a 3-chip adapter board, or make
a 6-chip 8088 board? Dealer's choice. But a small 8088 board is starting
to be a temptation...

Some of you may not know, I mess around with some small 8-bit processor
boards:

http://www.retrotechnology.com/memship/memship.html

And this fellow Lee Hart, has quite a number of them:

http://www.sunrise-ev.com/index.htm#microcomputers

so vest-pocket, or Altoids-can sized, 8-bit micros are amusing. These's
aren't the only ones of course, lots of Z80 and 8085 products of this sort.

Regards, Herb

[Jack Mcmullen]

From yesterday

Like I said just build up an adapter board the performs a 21821 x4 function using ram used by newerCMOS 8251 family AT chips that multiplexes ram and A0-7 and use 2 rows of header pins to plug into the 21821 far left socket left side and far right right side. Then add 1 header pin for 21821 #2 ,3 & 4 CS to get each higher bank and use as an address line for the single large RAM chip.. Your boards remain 100% pristine and now are usable just like originally designed

-----Original Message-----
From: Herb Johnson <hjoh...@retrotechnology.com>
To: intel-...@googlegroups.com
Sent: Fri, Jun 17, 2022 4:11 pm
Subject: Re: intel-devsys Help identifying an early 80s (late 70s?) Intel (SBC?) board

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[Bill Beech (NJ7P)]

Herb and Jack,

Yes, a small 8088-based few chip system is sure sounding tempting. 
Probably a better solution than building adapters for the 8755 and
21821.  You could use a pair of 32 Kb RAMS and have an interesting SBC!

Bill

[Jack Mcmullen]

Question...why replace the 8755?

-----Original Message-----
From: Bill Beech (NJ7P) <nj...@nj7p.info>

To: intel-...@googlegroups.com
Sent: Fri, Jun 17, 2022 10:50 pm
Subject: Re: intel-devsys Help identifying an early 80s (late 70s?) Intel (SBC?) board

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[Jack Mcmullen]

They are UV erased, cheap, on Ebay. Is there source for its contents or its binary like a 8088 monitor??

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[Bill Beech (NJ7P)]

Can you buy them anymore.  Who can program them?

Bill

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[craig andrews]

I have a few projects that used 8755s and i had good luck with the $6 ones i picked up from eBay.

Craig

On Jun 17, 2022, at 11:34 PM, Bill Beech (NJ7P) <nj...@nj7p.info> wrote:



To view this discussion on the web visit https://groups.google.com/d/msgid/intel-devsys/670e8138-1745-51b9-d0e7-e5fd694c78a5%40nj7p.info.

[Bill Beech (NJ7P)]

Can you program them?

Bill

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[andrewsofbg]

I would have to un-bury my programmer, but yes. 

[Bill Beech (NJ7P)]

Jack,

Right you are on availability.

But with under 10 chips, you could have a vest pocket 8088 system with 1 MB RAM and 512KB ROM.  Probably on the same sized board.

Bill

To view this discussion on the web visit https://groups.google.com/d/msgid/intel-devsys/840187730.5469786.1655533979908%40mail.yahoo.com.

[andrewsofbg]

But the 8755 has such a lovely (bit configured) port configuration

[Vale, Martyn]

 

I’ve bought a couple of 8755’s recently for an SDK-85 on eBay. I do have a programmer for these as well.

 

Martyn.

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[Lee Carter]

Again, WOW Mark!

> Given an 8755 does have some RAM onboard, I wonder if it would at least "boot"?

I was mistaken, the 8755 is EPROM and I/O only, no RAM.  So I guess that means some kind of RAM will need to be knocked up.  I like the idea of using something 'modern', with a couple of header strips to connect to the 21821 pads... I'm even considering building up one of my VPC boards to see if I could get it running.  Trouble is, I don't have the tools or skills to knock up a circuit board.  The last time I "made" a PCB was using tape, a copper-clad 'blank' PCB and etch.  (yeah, that too was ~40 years ago!)

The above said, I know someone who might be willing to make a replica of the VPC 'board.  He absolutely has the tools - here's one of his latest projects - https://github.com/max234252/MacLCII_Reloaded. Replicating the VPC 'board would be a doddle for him!  He may also be able to knock up a RAM 'board, or, replace the 21821 chip area with current components.  I'll drop him a mail and see what he thinks. 

[Lee Carter]

Meant to add... I've put all the files I have shared so far - including the files for the ISIS disk with the .88 files up on Bill's G.drive.

- \Intel_Devel\LeeC

ISIS disk  (folder)
VPC  (folder)
8755.pdf
tbs21.lst
tbs21.mac
Tiny Basic Fixes.txt

[andrewsofbg]

The intel x88 minimum system is a fun little board that is the x88 version of the 8085 3 chip minimum system. .  Just a 8088, 8755, 8155, 8284, and then a 8185 if you want another 1kb of RAM

[Herb Johnson]

I suggest a new discussion thread, of this title. Designing and
producing some kind of single-board 8088, is reasonably its own thing.

I'll give a view, others gave theirs.

My interests are in a sustained design, that's accessible to more people
rather than less. So an 8755 is not-so-common, and requires a
less-common programmer. A counter argument is "older is better", or of
course a matter of adherence to the original Intel design.

As I posted previously, I provide some support for a small 1802 board
and kit. That kit is sold, with parts, with manual, with a Web site.
It's been around for several years now. The basis of it, is an 1802
product 40 years old. Without detailing it further, that's a kind of
method, distribution and support that interests me; as regards modern
implementations of vintage projects.

http://www.retrotechnology.com/memship/memship.html

The original Intel board in possession of Lee Carter, of course, has
"unobtainium" RAM chips. If Lee's boards were mine, I'd preserve them as
artifacts, rather than adapt newer chips. It's his choice.

But that's how we got here. The current discussion of a new board of the
Intel "5-chip" alternative design of still available chips. Because code
for those products has emerged thanks to Lee's distributions. And
because Lee's vintage board can't be populated. Just pointing that out
as the apparent operational constraints.

----------------------------------------------

To Craig's point about the "But the 8755 has such a lovely (bit
configured) port configuration". How is the 8755 different from the
8255, beyond the presence of a 2K ROM in the 8755 (or the masked
programmed alternative)?

regards, Herb Johnson

[craig andrews]

Herb, I see the 8255 closer to the 8155 but without the RAM or counter and the 8255 having some individual bit set/reset is *very* nice. If the system doesn’t need the RAM or EPROM, then I don’t think the 8155 and 8755 would be my first choices.

As for new design, Herb is correct about the 8755 being on the fringe of programmability. So much so, I don’t even include those with a 8755 in my SBC-85 board offerings since they aren’t worth trouble

Craig

> On Jun 18, 2022, at 11:33 AM, Herb Johnson <hjoh...@retrotechnology.com> wrote:
>
> I suggest a new discussion thread, of this title. Designing and producing some kind of single-board 8088, is reasonably its own thing.

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[forjack842]

Apologize, also in a 51 group and have 51 on my brain. In your case with today's Cmos Ram you just need a couple 74HC373S to hold address and a W24512A CMOS RAM. If you make a board the size of the 4 21821 sockets, use header pins to plug into 21821 (0) left socket, 21821(3) right socket and pick up 21821 (1,2) chip selects your set.

Super Ram chip,use it myself on several 8085 projects.

https://www.ebay.com/itm/WINBOND-W24512AK-15-DIP-64K-X-8-HIGH-SPEED-CMOS-STATIC-RAM-/401214133693

Sent from my Galaxy

-------- Original message --------

From: Lee Carter <68mg...@gmail.com>

Date: 6/20/22 11:08 PM (GMT-08:00)

To: forjack842 <forja...@aol.com>

Subject: Re: intel-devsys Help identifying an early 80s (late 70s?) Intel (SBC?) board

There's no 8155 on this board, only the 8088, 8755, the 21821s and some support logic.

On Tue, 21 Jun 2022, 01:19 forjack842, <forja...@aol.com> wrote:

Correct, the 8155 has the RAM. 8755 is the Erasable PROM.

I have 2 email accts, not be choice either. I receive both email accts but the sending goes out using one or the other. So if I'm on my game I just reply and the group may or may no see it. Its My Bad....sorry

Sent via the Samsung Galaxy A11, an AT&T 4G LTE smartphone

-------- Original message --------

From: Lee Carter <68mg...@gmail.com>

Date: 6/20/22 3:08 PM (GMT-08:00)

To: forjack842 <forja...@aol.com>

Subject: Re: intel-devsys Help identifying an early 80s (late 70s?) Intel (SBC?) board

Where?  I don't see any mention of RAM on the 8755?  Also, is there a reason you're not replying to the Group?  I keep getting your mails privately.

- Lee  

On Sat, Jun 18, 2022 at 9:09 PM forjack842 <forja...@aol.com> wrote:

There's enough RAM to easily boot and preform monitor like functions. 256x8, 

Sent via the Samsung Galaxy A11, an AT&T 4G LTE smartphone

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[Lee Carter]

Thanks, am working with a friend to see what we can come up with.

[Lee Carter]

Interesting... I have several SRAMs that should work... 

- some 64Kx8 (W24256AK, UM61256FK) and some 32Kx8 (UM61512AK).  

I'll mention to my friend who's looking into this.

Thanks, Lee

[forjack842]

There ya go!!! Good Luck and keep us posted. I use ExpressPCB.and their schematic tools too.

Sent via the Samsung Galaxy A11, an AT&T 4G LTE smartphone

-------- Original message --------

From: Lee Carter <68mg...@gmail.com>

Date: 6/21/22 4:27 AM (GMT-08:00)

To: intel-...@googlegroups.com

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[Lee Carter]

Ha, ha... got those the wrong way 'round...  xx512 = 64Kx8, xx256 = 32Kx8.  Anyway, sounds like I have enough to do some experimenting.

[David Jones]

I just ran into this thread and know it is a bit old.  I also have a SCCS-85 from when I was at Purdue in the early 80's.  So here is my scan of the original ROM listing.  I would attach a bin file of my EPROM but mine seems to have developed bit rot over the years.  I've also attached the full manual.  Just wanted to get this out there so information on this SBC wouldn't get lost over time.

David

https://drive.google.com/drive/folders/18Bs6ey-Qp2RtQv__IXgPApSbTXGTgAGW?usp=share_link

[Bill Beech (NJ7P)]

David,

I have both documents down on my PC.  I will figure out where to put them on the web site in the next couple of days.

Thanks!

Bill

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[David Jones]

Thanks.  I'd love to see a link once you find a place for the files.  Eventually I am going to finish getting the source re-entered so I can make a new EPROM.  I'll put the source in the drive folder when I get it done.  I also have an un-build PCB around here somewhere that I am thinking of trying to scan.  Well see if I can get a good scan of it.  

David

[Herb Johnson]

https://ntrs.nasa.gov/api/citations/19850017632/downloads/19850017632.pdf

A NASA report which contains the same copy of that SCCS-85 manual, down
to markings on the rev 2 cover sheet.

I hope the "bit rot" of the 2708, isn't a result of using the wrong
EPROM reader or reader-setting to read a 2708. Few readers can read them
now. Details on the ROM are on pages 10-12 or so of the SCCS-85 manual.

If it's a 2716, make sure it's not a *TMS2716*, which is factually a
doubled-up 2708, and needs 2708 voltages. Please send a photo of the ROM
that shows brand and number. Also check the jumpering of the SCCS-85 to
confirm the ROM type as per the manual.

Inside the NASA /JPL report it says:

> The SCCS-85 circuit board is a unit designed by Robert Rindfuss
> that was purchased locally. It is revision 2 of the original circuit
> board design. T
local being JPL/Pasadena CA. I suspect "SCCS" is "Southern California
Computer Society" which is known for publishing a newsletter which
became "Interface Age" a national magazine. Searching desperately ...
"internet archive" has some of these under "interface age" and "SCCS
Interface". I didn't see the SCCS-85 in some of the early issues I ran
through.

Without comment, I don't think OCR of the source listing is a sure way
to extract the source or the binary. But that's for other people to
determine.

-regards HErb

On 4/2/2023 1:47 PM, David Jones wrote:> I just ran into this thread and

know it is a bit old. I also have a
> SCCS-85 from when I was at Purdue in the early 80's. So here is my scan
> of the original ROM listing. I would attach a bin file of my EPROM but
> mine seems to have developed bit rot over the years. I've also attached
> the full manual. Just wanted to get this out there so information on
> this SBC wouldn't get lost over time.
>
> David

[Herb Johnson]

In poking at the two documents of code - the source code in the SCCS
manual, the source listing PDF from a paper listing; I see there's changes!

The code that "initialize timer chip" is followed in the paper listing
PDFby an "lxi d, start ; print startup message". but in the manual PDF,
it's followed by "; initialize "answer"" code, then "print startup
message" code.

So - which code needs to be OCR'ed or replicated? from the manual? or
more likely, from the PDF'ed paper listing? Glad I caught this early.

regards Herb Johnson

[David Jones]

Yes that Nasa report is where I got that manual scan.  I thought about uploading the whole thing to the drive folder but to save size I just uploaded the manual part.  I will probably go back and do that later for completeness.  The EPROM is the one I got while at Purdue to go with the board and was programmed I think by the creator of the board.  It has been so long I am foggy on that last point.  I used a programmer that understands the 2708 EPROMs when reading it, the ME2700.   I've seen the code differences too.  Right now I am working from my paper copy I got with the original board and the scan I uploaded.

[David Jones]

I just added the Nasa report to the drive folder along with the bin file from reading my EPROM.

[David Jones]

I just noticed that the file size doesn't look right.  I will try reading it again this evening.

[Al Kossow]

On 4/3/23 6:32 AM, David Jones wrote:
> I just noticed that the file size doesn't look right.  I will try reading it again this evening.

you have a stuck address bit 2 in that image
have you tried cleaning the pins?

[Herb Johnson]

I have seen ROM images before, of 2708's with stuck bits. One had a
stuck bit in all the data! But knowledge of the hardware and processor
allowed several people to guess accurately almost all the program code
and data. I don't think that's necessary here. I wonder if stuck pins
are common with 2708's.

The alternatives are to OCR the source listing (lots of human editing)
or hand-copy the hex codes from the listing, disassemble to get the
source, and edit that up. The binary from the disassembly can be
compared to the corrupted ROM binary. Of course the assembled
instructions can be compared to the source listing.

Bill Beech pointed out to me, that the listing in the NASA/JPL manual
source, seems more recent than the paper listing, and has some
additions. David, do you have a preference between replicating the
original ROM, or running the most recent code? The differences may be
small and you could produce both sources.

Regards Herb Johnson

[David Jones]

Good idea about cleaning the pins.  I will do that before trying to read it again.  I would not be surprised if that is not the problem.  Thanks for the suggestion. 

I tried to OCR the scan of the source and had mixed luck.  It is actually what I am using to re-enter the code.  Just having to do a lot of clean up along the way.  I don't really have a preference on which code to use.  I was just going with the original since it just that to when I got the board :)

[Herb Johnson]

First: note that the source-listing in the manual, from the NASA/JPL
report, is NOT the same as the source listing David provided, from his
scanned paper listing. I am going with the source listing David
provided. This can be resolved later.

https://www.retrotechnology.com/z/sccs2.zip

contains the following:

sccs2.asm is pretty close to the DIS-assembled source, that matches the
assembled source from the paper listing from David. I'll explain
disassembled shortly.

sccs2.bin is pretty close to what David's ROM would be, if that ROM was
produced from David's assembled-source listing.

sccs2.dis is an odd text document. I produced it, by Herb-C-R. That is,
I eyeballed the David-provided source listing, and only typed in the
*hex codes* that the assembler produced, which of course are in the
assembler-produced source listing. A line of code in the assembler
listing, is a line of hex in the "dis" listing. So the two files (the
PDF listing, the .dis hex listing) roughly correspond line-for-line.
Look at the two files side by side and this will explain itself.

sccs2.cfg, drives a Bill Beech 8085 disassembler.
beechd85.exe is the 32-bit Windows *command line* compile
of the C-coded disassembler.
of course, the disassembler, produced the .asm file from the .bin file.

disbin.c, is my C code, for converting the "dis" file of hex codes, into
a binary file. The idea seem plausible, I wrote this code a few days ago.

disbin.exe is is the 32-bit Windows *command line* compile
of the C-coded program of that name.

notes.txt, shows the Windows 32-bit command line, for execution of the
two exe files.

----------------------

The dissassmbler is pretty useful, Bill and I have poked at it all
winter. I am uncertain about the general utility of the by-source-line
hex-codes to binary utility. It's not that complicated.

But the end results are 1) a binary file close to the original ROM
binary I hope, and 2) an adequate dis-assembly assembly of something
close to the listing document provided by David.

I've eyeballed the generated source, and it seems to "line up" with the
source listing in David's listing. I'm sure there's a few byte errors, I
found and corrected several before producing these files.

Presumably David et al, can correct by eyeball the disassembly against
the listing; produce a binary by assembling it. Then David can
presumably burn a ROM and operate his SCCS-85 board. This assumes he has
a complete SCCS-85 board and not just the PC board he noted.

David et al, could also edit the disassembly, to replace the generated
symbols (names) with the originals from the paper listing. Bill's
disassembler has means to include a symbols file with his disassembler.
I've not tested or used that feature in my slightly earlier version of
that disassembler. The code is small enough to use a text editor to
replace the systems with names. The first measure, is to replicate the
ROM binary for operation of the board, which ultimately validates the
binary and source.

OK? Code on the run and disassembly by eye is full of errors. Sorry.

Regards Herb Johnson

On 4/3/2023 11:29 AM, David Jones wrote:
> Good idea about cleaning the pins.  I will do that before trying to read
> it again.  I would not be surprised if that is not the problem.  Thanks
> for the suggestion.
>
> I tried to OCR the scan of the source and had mixed luck.  It is
> actually what I am using to re-enter the code.  Just having to do a lot
> of clean up along the way.  I don't really have a preference on which
> code to use.  I was just going with the original since it just that to
> when I got the board :)
>
>

[Lee Carter]

Hi everyone, sorry I've been away for a while - life and work have been extremely demanding for the last several months.  

@David, great to hear from another contemporary Boilermaker!  I'm hoping to find time to get my SCCS-85 up and running again - hopefully before the end of this year!  

Meanwhile, the attached might save a bit of typing!

Cheers, Lee

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[David Jones]

Herb: That was a pretty good idea on the disassembling the bin file.  Thanks for the file Lee and nice to run into another Boilermaker from the day :)

I've added some more files to the drive folder.  I found and scanned my original manual.  So it should be more readable than the one I'd put there before from Nasa.  I clean and re-read my original EPROM.  At a quick glance, it does not appear to match my listing.  But might match the Nasa listing.  I'll need to do more than a quick glance at the first few bytes.  I've also scanned my un-build board.  I need to check my built board.  Over the years I've stolen some chips from it.  So I need to see if I have everything needed to get it running again.  As a bonus, I even found the receipt from when I bought it - 8/20/1980 :)

David