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PolyMorphic Systems - 8080 CPU Board
This was the only CPU board Polymorphic Systems made.  That said, it was a very advanced board at the time it appeared.

8080 CPU    

The board had space for 3.5K of onboard RAM and ROM. This memory occupies a contiguous block of 4K and could via jumpers be placed at 0,8000H or E000H.  Space for 3 2708 EPROMS were on the board.  The ROM's occupy the first 3K of the 4K space. There was one 512 RAM chip on the board as well.  A Real Time Clock was obtained by processing the 50/60 Hz power line ripple.  

The white chip (not the CPU), was the famous "4.0 Monitor" ROM which had a simulated front panel, and allowed single-stepping of assembly language programs.  It could also load and store programs on cassette tape through a separate interface.  This was the only ROM installed on the original Poly-88.  The other two ROMs, including the one marked V.75  (below), were added to support floppy disks. 
Two sockets at the upper right could be connected to "serial mini-cards" driven by the 8251 UART on the CPU card.  Only one of the two cards could be in use at any time.  One could be configured for audio in/out and was connected to a cassette tape recorder for program storage.  The other provided RS232 signals to a serial printer, which was the most common kind of printer before the IBM-PC made a parallel Centronics interface their standard.

The manual for this board (along with info about other boards in the Poly-88) can be obtained here
There was a later mod to modify the SM1 and Wait S-100 signals. This can be obtained here

Poyy-88 8080 CPU-2

There was a small add-on card that was sometimes attached to the Poly-88 CPU card that had to do I think with processing interrupts. It is shown above. Would welcome comments on this.

Other PolyMorphic Systems S-100 Boards
Video Display Board    8080 CPU  FDC


This page was last modified on 12/07/2009