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Thread: Poly 88 case

  1. #11

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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
    Last edited by Dwight Elvey; November 8th, 2017 at 07:11 AM.

  2. #12

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    Quote Originally Posted by Dwight Elvey View Post
    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
    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
    Last edited by DDS; November 8th, 2017 at 06:31 PM.
    "It's all bits on the bus, Cowboy! It's all bits on the bus!" -- Tom Beck, #1ESS Instructor, Southern Bell Opa Locka Training Center

  3. #13
    Join Date
    Nov 2012
    Location
    Richmond Hill, Ontario, Canada
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    884

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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

  4. #14
    Join Date
    Nov 2012
    Location
    Richmond Hill, Ontario, Canada
    Posts
    884

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    For those interested, I just uploaded a bunch of Polymorphic Systems marketing type files that have multiple brochures, price lists and newspaper articles on the POLY 88 and System 8813 computer systems.

    http://vintagecomputer.ca/files-area...rphic_systems/

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