Task: Boot the CP/M Operating System Using the 1090 XL Expansion System for the Atari XL and XE 8-Bit Computers
Needed: Atari XL computer, new 1090 XL expansion board, CP/M card for the 1090 XL, 80-column card for the 1090 XL
Time: 15-30 minutes
Introduction
I have previously posted about several different ways you can boot the Z-80-based CP/M operating system for use with the Atari 8-bit computers. First, you can boot CP/M from an Indus GT disk drive that has the required Z-80 processor built in for handing drive functions. This method requires a RAM upgrade. The second approach is to boot it from an emulator running on a FujiNet device. The third approach, which I have not yet posted about, requires an ATR8000 peripheral with 64K of RAM connected to a standard disk drive. This latter approach is by far the most difficult as ATR8000s are hard to find, and you need the CP/M boot disks.
There is now a new option for booting CP/M using a Z-80 card plugged into a newly made 1090 XL expansion module that plugs into the PBI slot on the back of an Atari 800XL computer (or an XE computer with an ECI to PBI adaptor).
Instructions
First, purchase the 1090 expansion board from Tindie for $115. Thanks Brian Reifsnyder and Ken Ames for making this possible.
Second, purchase the 80-column expansion card for $85 each.
Third, purchase the Z-80 CP/M card for $99 each. Be sure and pay extra for the Z-80 CPU to be included. Otherwise, you will need to purchase your own and install it in the socket on the board.
Fourth, download the latest ATR file containing the software needed to run the card. As of this post, the latest version is cpm104.atr available from this thread on Atari Age. You will need to make a floppy disk for booting from a disk drive or boot using SIO2PC and RespeQT, for example.
Fifth, install the 1090 XL. You will need a 9V power adapter (e.g. like the one used for the Atari 800 and 1050). The 1090 XL comes with a ribbon cable that plugs into the PBI slot on the back of the 800XL e.g. Pop off the protective cover. You are supposed to be able to use with the 130XE through the ECI port with an ECI to PBI adaptor. I have not tried this.
Sixth, plug in the 80-column board into a free slot with the HDMI port facing the back of the 1090 main board toward the power switch. Then connect to a modern LED screen with an HDMI cable. I used the slot closest to the power supply.
Seventh, plug in the CP/M board with the longer part of the board over the 1090 XL board such the chips are facing away from the power supply. Note that for some reason my board only worked in slots 1, 3, and 5. You may need to move it around to get it to work. The developers are aware of this issue.
Eighth, power on the 1090 XL board, insert the boot disk in your drive or drive emulator, and boot the Atari. If all goes well, you should see the CP/M screen with the text “Atari 64K CP/M 2.2” and prompt as shown above. Type DIR at the prompt to see what executables are available for use. If you get a screen with red border, then something has gone wrong. Check all steps and repeat.
Comments
The FujiNet is probably to the better way to experience CP/M. However, I really like the idea of booting from a real Z-80 processor on the 1090 XL, Indus GT, or ATR8000.
The three cards together will set you back about $300. This is a pricey project. However, I am particularly excited about these modern boards for the Atari 8-bit computers. Also, I am a huge fan of CP/M and am always excited to try additional options for running it.
This project took a little while to come together. First, I neglected to order my CP/M card with the Z-80 processor included. I had to order one from eBay. They are only about $10 or so. Make sure you get the 10MHz one. Second, it took me a day or two to figure out that the slot I was using (#4) for the CP/M card was not working. Once I moved it to slot #5 I was able to get it to boot.
I have not done anything other than get the card to boot. What else can we do with this?? How do we get more CP/M software onto it?
2024 is the 50th anniversary of CP/M.