A new build with a custon-circuit board can be found here: https://github.com/jasonfrowe/2600MultiCart/tree/main

atari2600cart

DIY Atari 2600+ Cart

Using a Raspberry Pi PICO to emulate a 28C256 32KB EEPROM which is then interfaced to an Atari 2600 cartridge card.

The ROM emulator is based on PicoROM (https://github.com/nickbild/picoROM) and the cartridge PCB is from https://www.pcbway.com/project/shareproject/ATARI_2600_MULTI_GAME_CARTRIDGE_PCB.html.

The cart allows for 16 different cartridges of 4K, 8K, 16K and 32K sizes with standard bankswitching. A reset switch is wired, which allows for hot-swapping cartridges on the 2600+.

A helper script 'make_romheaders.py' is provided that will read in ROMS from the roms/ directory and create the necesssary roms_XX.h headers.

Build Log

I'm going to put together a build walk through to help those that may want to create their own Pico Multi-Cart for the 2600+

Required Materials

Part	Description	Mouser Part Number
Raspberry Pi Pico	This build uses the non-wifi version	358-SC0915
Protoboard	Larger is okay. There is barely enough room with the one I picked	N/A
Cartridge board	I used this simple project from PCBWay to get a card interface	See intro for link
SN74LS04N	Hex Inverter	595-SN74LS04N
SN74LVC245AN x2	Bus Transceivers Tri-State Octal Bus	595-SN74LVC245AN
10 K ohm resistor x 4	Generic resistors	N/A
1 K ohm resistor	Generic resistors	N/A
2 K ohm resistor	Generic resistors	N/A
1N4007 diode	Diode	N/A
104 capacitor	0.1uF ceramic capacitor	N/A
Sockets and headers	These are optional, but recommended -- and order extras!	571-1-2199299-2
Button switch	I used an Omron B3F, but pick what you like.	N/A
Dip switches	4 bank needed.	655-2454982-3

Layout.

This is the layout I went with. Using sockets really helps to plan the build and if you mess up you only lose a socket not the IC.

Wiring

I used Wire Wrap Wire as it's very flexable and thin making it easy to work with. Using thicker wires makes everything too cramped.