Task: Boot the CP/M Operating System on Your Apple II
Needed: a2Pico Card, floppy drive emulator, Apple II Computer
Time: 15-30 minutes
Introduction
I never got a chance to try the CP/M operating system on computers with Z-80 processors back in the 1980s. As a result, I have a strong interest in this OS and am particularly interested in the special devices to get it to boot on 6502-based computers like the Apple II. One solution to this was the Microsoft SoftCard which was the first to offer a special card with a Z-80 processor on it for supporting CP/M applications. Several cards from other manufacturers followed including the Appli-Card from Personal Computer Peripherals, Inc. (PCPI). Of course, these are hard to find and can be expensive today. Fortunately, the a2Pico card (shown below) can emulate the Appli-Card allowing your Apple II to boot CP/M using a modern Raspberry-Pi Pico device that can be purchased for less than $50.
Instructions
Assuming you have already purchased an a2Pico card, download the Appli-Card firmware for the Pico from the GitHub.
To flash the a2Pico with the firmware simply attached a micro-USB cable from the Pico to your PC while holding down the BOOTSEL button. Release once plugged in. Open the Pi Pico folder and drop in the .UF2 firmware file. It will automatically flash the Pi Pico and close the folder. The a2Pico board is now ready to insert into slot #7 of the Apple II.
Next, download the Appli-Card CP/M systems disks. The zip file is mentioned in this post. These will need to be loaded onto a floppy drive emulator such as the wDrive or the Floppy Emu which is what I used. The PCPIBOOT.DSK file is the one the Appli-Card looks for to boot CP/M. Make sure this is loaded into the boot slot of the emulator.
You are now ready to power on the computer. You should see the CP/M boot screen appear. Type DIR to see the available programs.
Comments
Thanks to the developers of the a2Pico card for this awesome emulator!