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  Polymorphic Systems Poly 88 by Bill Degnan - 05/10/2011 20:14
The Polymorphic Systems Model Poly 88 S-100 Computer


Remove the orange cover to reveal a 5-slot S-100 backplane, fan, and power supply


The rear view ports. Serial number 0846.


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Restoration will be a challenge, but it's worth the effort. No testing yet. System is missing 8080 chip, fuse, and who knows what else.

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  Poly 88 Restoration Notes by Bill Degnan - 05/20/2011 23:42
Johnathan Chapman fixed the fuse and repaired the power supply. He was also able to boot the system using a Cromemco ZCB card and with Dajen System Central Interface (SCI) prom card.

The drill holes in the front and top are not from the factory, too bad, but the original owner probably needed to add vents to keep the system cool.

Herb Johnson also recently came upon a Poly 88. He traded me an 8080 chip to replace the missing CPU of my processor card, for a Bell and Howell Apple II drive. He also informed me that the missing chip from the video board is a MCM6571A. Herb says:

"..the MCM6571A ROM is a really old-school ROM with three power voltages. Motorola later made a part MCM66714 which only used one power voltage (+5 of course), and the SSM folks used it on their video cards - same pins except the two odd voltages can be grounded or used for chip selects.."


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  POLY 88 Power Supply by Don DiGalbo - 07/10/2011 14:33
I am restoring a POLY 88 and the large can capacitor in the power supply is missing. I am trying to identify the specs on this cap and was wondering if you could tell me what is written on the can. I know it is 15vdc.

Thanks,

Don

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  Power supply caps Poly 88 by Bill Degnan - 07/15/2011 02:22
Don
The large cap is a General Electric "15 VDC 18 SURGE"

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  burned out traces by Bill Degnan - 12/16/2011 20:15
The 16V traces/lines of 3 of 7 S-100 slots (including the side ones) were burned out. I can get 8V on all slots however. I took the system apart and inspected the underside of the backplane to confirm. The only way to fix this is to put jumper wires to replace the broken traces. It looks like this system was done by hand, there is a lot of clean up necessary to get all S-100 lines on all slots cleaned up. ug.

UPDATE: All three Polys I have worked on have this problem. I have picked up some 28-ish gauge wire for repairs.

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