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Poly 88 case

falter

falter

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I just picked up a Poly-88 case only.. wondering what you guys think my odds are of finding actual Poly boards? I seem to recall seeing some on ebay but can't remember how long ago.

An S100 bus is compatible with most any S100 card, right? I'm thinking if I can't find the actual Poly boards I can shove something else in there.. like this Applied Tech DG680 board I got.
 
They do come up now and then, so if you keep an eye out you may well end up with a board set.

falter said:
An S100 bus is compatible with most any S100 card, right?
Click to expand...

Well, sort of. You can plug most S-100 boards into the Poly 88 chassis, but just because something is S-100 doesn't necessarily mean it'll work with other S-100 boards from a different manufacturer (or even the same manufacturer but from two different eras!). With a little chassis like the Poly 88, you should probably look for a single-board computer with at least the CPU, ROM, and console all on one board. Some very late SBCs will even have your full 64K of RAM.
 
Video boards are more common than CPU cards as they had early graphics
and were memory based.
The video board could also take a parallel keyboard, so no separate monitor needed.
They did make RAM boards but none of the Poly88s I've seen had them.
There are two holes on the back of the chassis that look to be for RS232. These would normally
have a serial buffer board and a cassette interface board. It is unlikely you'd find one of these
unless attached to a chassis.
Dwight
 
Question - *is* the Poly 88 historically significant? I had been led to believe it was but I'm not convinced it is.. doesn't seem to me it does anything unique vs. the Sol-20 and the Sol I thought was out earlier..
 
The CPU card with RAM, ROM and cassette interface is probably mildly significant. I don't know if they were the first to integrate that much though.
 
Yeah. I'm just trying to figure out why they're so hotly contested. They're clearly very collectible.. I just don't understand why they stand shoulder to shoulder with a SOL.
 
It was also a single reset button machine.
It had a monitor in ROM rather than switches.
The cassette interface wasn't on the CPU, only the USART
was.
Dwight
 
I think its claim to fame was the single button reset and no hardware front panel. The monitor in ROM was quite good. Since the video was memory mapped, it was fast to update. It showed a multi-line memory window, the registers and for the pointer registers, a single line of 8 bytes, as I recall. It highlighted the byte actually pointed to.
It had a tape read but there just wasn't enough room for the tape write. One had to enter it from the keyboard and then save itself to the cassette.
Dwight
 
Years ago a friend gave me a Poly88 that was non functional. He also gave me a TEI enclosure with the Poly88 card set in it. One quirk on this Poly88 is that there's a cut out on each side that exposes card edge fingers on the motherboard. Supposedly this was a way to add S100 slots and power supply capacity to the system. You could just buy another box and connect the two motherboard sections somehow. These things were rare and I'd be willing to bet any original connectors or ribbon cables to connect two boxes would be even more so. And that's assuming Polymorphic didn't leave that as a DIY project for the buyer.

In this picture, you can see something with two card edge connectors attached to the near side of the motherboard. That could be a piece of original equipment that got separated from the unit I was given. Or it could be one person's way of making use of the expansion feature.

http://deramp.com/pictures/poly88_inside1.jpg

I was just cruising about for any info on a motherboard to motherboard connector. When I got to Herb Johnson's site, the name Dwight Elvey popped up.

http://www.retrotechnology.com/restore/poly_restore.html

Mr. Elvey, could you shed any light on the Poly88 expansion feature?
 
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Hi
I'm afraid you know as much about the expansion as I do. Polymorphic went on to make the System88. I believe you are right that it was intended for expansion. You have to remember that the Poly88 came out right around the time that DRAM boards were becoming available so there was less need for the expansion of things like 8K static boards.
I made the DRAM modification to my CPU card and used a DRAM board. I modified the address decoder to be 4K or 8K ( I forget which ) to work around the monitor and video board when I had all 3 rows of 16K DRAMs. Since the RAM was all on one board, there was little need for expansion. As I recall it was expected that there was RAM starting a 2000H, not a 16K boundary.
The biggest issue with the Poly88 was cooling. Mine had the small fan kit installed when I got it but even with that there was not enough cooling so I always ran it with the cover off.
The person that might know something about the expansion is Marvin Johnston. I think he sometimes is on the classic comp news group and may be on this one as well. Marvin has quite a bit of the original stuff from the company when if folded.
One wonders if the one you have could have been used as is to plug a board into. I never looked at the pin layout. It would be useful to debug boards if that was the case.
I was noticing your unit had one of the I/O cards but it isn't clear if it is the serial card or the cassette card, connected to the CPU board. The picture isn't clear enough. I can see there is the card for the keyboard. These often had a resistor and zener diode on them for those keyboards that needed a negative voltage. The CPU card had the option for this as well but I suspect they found it more convenient to have the matching keyboard and connector than to deal with modifying the CPU card for each.
Dwight
 
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Dwight Elvey said:
I was noticing your unit had one of the I/O cards but it isn't clear if it is the serial card or the cassette card, connected to the CPU board. The picture isn't clear enough. I can see there is the card for the keyboard. These often had a resistor and zener diode on them for those keyboards that needed a negative voltage. The CPU card had the option for this as well but I suspect they found it more convenient to have the matching keyboard and connector than to deal with modifying the CPU card for each.
Dwight
Click to expand...

That's not my unit in the pictures. that's an example I just grabbed off the web in a hurry. Mine had the cards pulled out before I got it. The Poly88 case is in a stack of stuff I need to fix, and the TEI box the cards ended up in is in another stack. The good news is I'm not going to run out of projects any time soon.

But when it was given to me the original owner demonstrated how the monitor allowed you to edit memory and registers on the screen in hex then jump to the program. The display looked a lot like a typical DOS debug session. And this was when Altair & Imsai users were still flipping front panel switches. I later saw a similar layout when using the L$SNAP macro on a Univac 1100/80 and that wasn't real time. So the Poly88 user interface was way ahead of it's time.

I found this page that's a pretty good description of the software front panel.

http://www.polymorphic-computers.com/frontpanel.html
 
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This may help the Poly 88 expansion discussion.

I have the Poly 88 brochure that was mixed in with the documentation of my Poly System 8813. The specs say:

Expandability: Up to 4 chassis may be plugged together.

Here is also a page of the Polymorphic Systems price list that details the cost of:

1. An assembled and tested POLY 88 chassis @ $355
2. An assembled an tested "Expansion chassis for POLY 88" @ $375

Could be a normal chassis with dual S-100 card edge connectors connected together but that wouldn't allow for up to 4 chassis to be plugged together. As a side note, there are no pictures of the Poly 88 in any sort of expanded form or pictures of an expansion unit.

Polymorphic System Price List page.jpg
 
Question:

What are the bare essentials to have a running Poly 88? I know about the CPU card and Video interface.. did you need a RAM board or serial/cassette board of some sort? Also, is the monitor contained on just one ROM?
 
IIRC there's some RAM on the CPU board, but not much. So, you want to have a CPU board, video interface, and some additional RAM. IIRC, cassette and serial are provided off of the CPU board (the interface on the back panel isn't just a cable, there's a circuit board that goes with it, and attaches by ribbon to the CPU), and the video card provides the parallel ASCII keyboard interface.

I'll probably end up putting a TDL ZPU and TDL SMB in the empty Poly-88 chassis I have.
 
I agree with all that Glitch said.

If one has a Poly-88 chassis only, I would suggest looking into the JAIR-8080 by Josh Bensdadon. It's available on eBay from time to time, but less expensive to contact Josh directly on the S-100 Group (https://groups.google.com/forum/#!forum/s100computers). This is an all-on-one-board system that is highly configurable to allow you to use other memory, I/O PROMs, disk interfaces, etc. Plus it has an SD Card interface onboard with CP/M too. An Excellent single board computer system, perfectly suited to a tiny chassis like the Poly-88.

smp
 
I do have a few interesting S100 cpu boards to play with.. one is an Australian DG680.. a Z80 board but the only problem is I'm missing the ROM and it needs a DG640 (I think that's the model) video card.

I also have that MicroDaSys card. And an unbuilt Byte MPU card.

I'm just a bit fuzzy on the whole active termination business and what's compatible with what for S100 machines.
 
The Poly-88 is just a straight S-100 bus, no termination. Most older cards will work with it. You're not going to get a 10 MHz Z80 or 8088 or something to play nice on an unterminated bus, but it's fine for old 2-4 MHz systems. It's what was found in the Altair and IMSAI. You can add termination on a terminator card, or multifunction card, if you decide you need it.

It basically all mostly works together. Sometimes there are configuration changes or cut-and-jump changes you need to make on some boards to work in some systems.

With a chassis as small as the Poly-88, you want either a two-board system that was sort of meant to go together and give you a basic system, like the original CPU+Video board, or the TDL ZPU+SMB, or take it a step further and get a SBC. Josh's JAIR-8080 is one modern option, there are *lots* of vintage options. I personally like the Vector Graphic ZCB for a S-100 SBC -- it's a 2 or 4 MHz Z80, console serial port, parallel port, ROM, bootstrap circuit, and some RAM on a single card. It's simple and reliable, and can be made to look like an IMSAI or North Star Horizon serial console easily. The Vector Graphic ROM monitor is good.

PM me if you decide you'd like something put together that will definitely work -- you can either send me your boards and I'll get them working together, or I can see what I've got that'll fit the bill.
 
falter said:
I do have a few interesting S100 cpu boards to play with.. one is an Australian DG680.. a Z80 board but the only problem is I'm missing the ROM and it needs a DG640 (I think that's the model) video card.
Click to expand...

My second computer was Applied Technology's S100 system using the DG680 and DG640 with the optional PCG board, I liked it a lot and ported TRS-80 software and the VDO text editor from BYTE magazine to it among other things.
If you are looking for the DGOS rom (I recall it stood for 'David Griffiths Operating System') or a DG640 you might try posting a want on the Microbee Users Forum https://www.microbee-mspp.org.au/forum/ The Microbee was the successor to that S100 machine, which I found out annoyingly they dropped like a hot rock just as soon as it was released.
The Microbee must have had a modified DGOS as I managed to backwards port some Microbee cassette tape software back to the DG680, the keyboard routines were different as the Microbee hardware I think used a light pen trigger to strobe, or something like that. The keyboard I had on my system was a blue GRI parallel ASCII unit absolutely identical to this one https://www.ebay.com/itm/New-Vintag...ssional-ASCII-Keyboard-Model-756/112812496243

You may find the DG680 will run with probably any 64x16 memory mapped video card starting up around D000H or thereabouts. A number of the games AT offered on cassette were ports of the Sol-20 ones, which I did not know until just a few years ago. I built a hand controller with left/right/fire buttons on it to play the 'shoot at overhead planes' game, can't recall its name. And a D/A converter/amp/speaker to play four-voice music from a 1970s BYTE article on waveform summation, a friend wrote the Z80 polyphonic code which I still have somewhere along with the D/A board.
 
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