A8PicoCart for Atari 8-Bit

Description

The A8PicoCart is a multi-cart for the Atari 8-bit XL/XE by Robin Edwards. This cartridge is based on the earlier UnoCart but uses a Raspberry Pi Pico (RP2040) clone.  It has 16MB of flash on board for storing CAR, ROM, XEX and ATR files. An on screen menu is available when starting the Atari to select the desired file. A portion of the sale price for each cartridge will be donated to the designer. If you wish to donate more, information is available here.

Since the original design is open source, I made some improvements to the schematic and the modified the case. The original design does not allow connecting the USB-C port from PC to the cart when it’s plugged into the Atari so I’ve added a protection diode and two MOSFETs to protect the Atari when turned off and the cart connected to the PC. The USB-C port is now exposed on top of the cartridge for easy access without needing to remove it from the Atari. The cart reset button was also moved to the top. On back is the BOOTSEL button which is used to upgrade the firmware on the cartridge. The case is 3D printed in Dark Brown PLA with a Bone White inlay around the logo.

While the A8PicoCart was designed for the XL/XE series Atari Computers, I tested it on my Atari 400 and it did work with some caveats. It seems to only work on the 400 with the original Atari branded 48K RAM upgrade. At power on, the screen is garbled and pressing System Reset brings you to the menu. Other than that, it seemed to work ok for most ROM, CAR and XEX files that I tested. There are issues reported with the Atari 800 on the AtariAge thread for the A8PicoCart.

The cartridge supports ROM, CAR, XEX and ATR files. Full details of the supported filetypes are included in the user manual available at https://github.com/mozzwald/A8PicoCart/blob/main/A8PicoCart%20Manual.pdf. Design files for my version of the cart are also in the repo.

List of supported CAR types:

• Standard Atari 8k
• Standard Atari 16k
• Atari XEGS 32-128k
• AtariMax 1mbit (128k)
• Switchable XEGS 32-128k
• Megacart 16-128k
• Bounty Bob
• Williams 32k, 64k
• OSS 8k
• OSS 16k (034M)
• OSS 16k (043M)
• OSS 16k (type B)
• SIC!Cart (128k only)
• SDX 64k
• Diamond 64k
• Express 64k
• SDX 128k
• Blizzard 16k
• 4k
• Turbosoft 64k, 128k
• ATRAX 128k
• MicroCalc/Ultracart 32k