Poly-88 inside
Poly-88 inside
Poly-88 rear
Poly-88 with Floppies
Poly-88 CP/M

PolyMorphic Systems

This page provides useful information and links related to computers and accessories from PolyMorphic Systems.


The Poly-88 computer was introduced in 1976. Originally named the "Micro-Altair," the name was changed to "Poly-88" after objections from MITS, the manufacturer of the Altair 8800. The Poly-88 is very compact using a five slot S-100 bus. Pictured on the right is a Poly-88 from my collection.

The computer is configured as follows:

Also pictured is the Poly-88 running CP/M with a pair of drives connected to a Micropolis disk controller. Due to the fact that the Poly-88 has PROM in the lower 3K of address space and CP/M requires RAM starting at address zero, CP/M was not common on the Polymorphic computers. Also, keyboard input and serial I/O can only be performed using interrupts and only while the PROM address space on the CPU board is enabled. This further complicates development of a CP/M BIOS for the Poly.

To make PolyMorphic computers more CP/M friendly, Martin Eberhard has written an extension to the orignal Poly-88 PROM monitor he calls "Polex." Polex installs in the second PROM socket on the CPU board and is automatically called and initialized by the original Poly-88 PROM. Along with a few useful operator commands, Polex also manages real-time swapping of RAM and PROM in the lower address space and provides console and serial I/O entry points for use by a CP/M BIOS.

The Polex PROM requires a simple "Phantom" mod to the CPU board that allows use of RAM boards that support the Phantom feature. Even with the Phantom mod and the Polex PROM in place, all original functions of the Poly-88 remain and operate the same.

To date, I have ported versions of CP/M that run on the Poly-88 (with Polex) for the Micropolis controller, both the North Star single and double density controllers, and the Altair 8 inch floppy controller. I hope to port CP/M to the original PolyMorphic floppy controller soon. The Polex PROM, CP/M disk images, disk image transfer utililities, etc., are available below under "Useful Links."

The disk operating system created and sold by PolyMorphic was called "System 88" or "Exec". Disk images have been archived and an emulator is available on Bob Bybee's excellent PolyMorphic Website. I plan on getting Exec up and running on my Poly-88 soon.

System 8813

Coming Soon

Useful Links