In 1984, there is extensive evidence that Atari designed two CP/M Z80 cards for the 1090XL. One of these cards was a non-functional prototype and one may still exist. A schematic diagram exists of the other card. The discovered software appears to work with the card version for which only a schematic diagram remains. Either of these cards did not have their own memory and, instead, used memory from one of Atari's 64k 1090XL memory cards.

This card is a full-size updated version, in a classic styling, with 64k of on-board memory. It's function is based upon the schematic of the second card. Unlike many 1090XL cards, this card capitalizes on 4 programmable logic chips so as to reduce the chip count and add the 64k of on-board memory.

The pictures are as follows:

1. CP/M running on this card on a 1090XL with an optional 80 column RP board (not included).

2. The front side of the card described within this listing. (A Z-80 chip is shown installed and is optional.)

3. The back side of the card described within this listing.

At this time, this card's CP/M OS customization and utilities are on an alpha state of development. As all available software either has source code available and/or has been open-sourced, it is hoped that some buyers will improve and released updated versions of the OS customization and software. Please consider the software condition to be "a work in progress".

The current state of the software is as follows:

• The boot process works properly and CP/M executes.

• Printer support still needs added to the CP/M BIOS.

• Printer support still needs added to the Atari I/O code.

• The Atari can send an interrupt to the Z-80 and it has been confirmed the interrupt system works.

• The interrupt system still needs properly implemented.

• CP/M can be used to format floppy disks in 1050 enhanced density format via a custom format.com utility.

• The system can be installed on disks and disks can be copied from within CP/M.

• Other CP/M utilities, such as stat.com, appear to function.

• It is believed that programs, such as WordStar, will require some additional changes to either the CP/M BIOS and/or the Atari I/O code.

• A boot/OS/utilities disk has been created.

• Files can be copied from an Atari DOS 2 disk onto a CP/M disk.

It is my belief that current buyers will be developers who would like to contribute to this "embryonic" CP/M environment.

As the Z-80 CPU has recently, and sadly, been discontinued this card is available with or without the Z-80 CPU. Due to my minimal supply of Z-80 CPU's, I have them listed at a premium price point. This card requires the Z-80 CPU have a minimum speed of 8Mhz.

Shipping within the US will require a signature upon delivery.

Please allow several business days for shipment as these cards are made on an as-needed basis.

More information, source code, etc., can be found here: AtariAge Z-80 Thread