Purchase an A2Pico Card for Emulating Multiple Devices on Your Apple II Computer (30-60 mins)

Hardware, Software

Task: Purchase an A2Pico Card for the Apple II

Needed: A2Pico card, Apple II computer

Time: 30-60 minutes

Introduction

One of the joys of owning an Apple II computer is experimenting with the many varieties of cards that expand the functionality of the system. These can include cards for adding RAM, a mouse port, and interesting cards such as the Microsoft SoftCard (shown below) that allows the Apple to boot the CP/M operating system via an onboard Z-80 processor. Unfortunately, many of these cards can be hard to find or expensive.

Microsoft SoftCard with a Z-80 Processor (chip with white dot) for Booting CP/M

The A2Pico project is an open-source hardware and software solution that uses a Raspberry Pi Pico microcontroller to emulate peripherals for the Apple II. It is typically implemented as a small expansion card that plugs into an Apple II slot and provides functionality such as ProDOS-compatible hard disk emulation (.HDV, .2MG, and .PO files). This functionality is a cheaper and more elegant solution to hard disk emulation in the Apple II than previous devices such as the BOOTI that I recently posted about. Of particular interest to me is the ability to emulate the Appli-Card that was a competitor to the Microsoft SoftCard for booting into CP/M. See my later post about using the a2Pico for emulating the Appli-Card.

The open-source system leverages the Pico’s GPIO and programmable I/O (PIO) capabilities to interface directly with the Apple II bus. Users typically build or purchase assembled boards and load firmware onto the Raspberry Pi Pico. Configuration is done through files on the SD card, and functionality can vary based on the firmware version and supported features.

Instructions

First, purchase an a2Pico card. I have two different versions of the card I got from two different vendors (see image below). The one on the left I purchased from Joe’s Computer Museum (USA) for around $30 ($44 with taxes and shipping). They also sell a USB port to mount on the back panel of the computer for easy access. The second one I purchased (right) was from Ralle Palaveev (UK) who no longer seems to have any in stock. Joe’s provides the option to select the firmware you want pre-installed making this plug-and-play. I was also able to find these for sale on eBay.

Next let’s update or change the firmware. Most people will likely want to use the a2RetroNET firmware that allows the a2Pico to be used as a SmartPort hard drive. To be able to access hard drive images from the micro-SD card, download the latest a2RetroNET-USB .UF2 file. To flash 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. Note that the jumper on the board needs to be set to USB ON to use the SD card and USB option highlighted here. Mine had that set by default.

Next, let’s get some hard drive images on the micro-SD card that can then be selected and booted from configuration tool. I recommend starting with Total Replay that provides dozens of games from a nice easy to use interface. Download the .HDV file and drop it onto a FAT32 formatted micro-SD card. You can also download and transfer Total Replay II with more games and Pitch Dark that allows you to explore and play Infocom games like Zork. Any ProDOS (.PO) file should work as well. I read in the README that you can plug in a USB drive to the Pi Pico micro-USB port as an emulated floppy drive. I have not tried that option.

Before we boot the device, you can optionally create an INI text file (as shown below) with the filename A2retroNET.txt and place it in the root directory of your SD card. Assign your hard drive images and ProDOS files to one or more of the eight drive slots. The card will automatically boot the first drive after a delay of X seconds that you set (mine is set to 6 seconds).

Insert the a2Pico card into slot #7 and boot the Apple II. You should see the Apple //e letters at the top and the delay countdown in the bottom right. You can press C during the countdown to get to the configuration menu. Here you can assign drive slots by tabbing between the slot panel on top and the files to assign on bottom. You can also select a specific drive by pressing that number during the countdown or just wait for drive one to boot. That is it!

Comments

This is an amazing device and with a great price point at less than $50. I love the Appli-Card emulation for CP/M.

Here is a list of projects for the a2Pico to check out that I took from the main GitHub page: