The Multijoy is a device to allow you to plug up to 16 joysticks into an Atari 8-bit computer with just 2 joystick ports.
Games have to either be written to support the Multijoy or be hacked to add support, for you to use the Multijoy with them but this device in various incarnations has been around since the late 90’s and there are now lots of games available including hacked versions of all the 4 player games that Atari 400/800 users could play but XL/XE users couldn’t due to a lack of available joystick ports.
If you’d like to see what games are available, here is a link to Fandals website where he has a good search that pulls them all together, currently there are 61 games that use the Multjoy, the newest of which “Sails of Doom” was my inspiration for making this Multijoy in the first place.
Sails of Doom was released in 2018 along with FLOP62 the discmag of Atariklub.cz. I didn’t have a Multijoy to play it; nobody was making them, and I didn’t want to go the hard-wired route so I decided to use this as a learning experience and get into using KiCad to design circuit boards.
This is the revised 2007 schematic by Radek Štěrba (Raster), it’s a pretty simple circuit.
Bill of Materials
- 04 x 10k Resistors – (CF14JT10K0CT-ND)
- 01 x 100nF Ceramic Capacitor – (1109PHCT-ND)
- 01 x 74ALS138 Decoder/Demultiplexer – (296-1639-5-ND)
- 40 x 1n4148 (or 1n5819 Schottky) Diodes – (1N4148-TPMSCT-ND or 497-7053-1-ND)
- 08 x Male 9-Pin DSub connectors – (AE10972-ND)
- 02 x Female 9-Socket DSub connectors – (AE11063-ND)
The original schematic calls for 1n4148 diodes and these work great if you are using the Multijoy with an original Atari but if you are using a 1088XEL the voltage drop is too great and the fire buttons don’t work so I switched to using Schottky diodes for their smaller voltage drop and that fixes it. Soldering the IC directly to the board allows it to sit low enough that all the components are protected by the metal ring formed by the dsub connectors so no case is required.
Over the years many versions of the Multijoy have appeared, mostly hand built into project boxes, manually soldering all the components directly to the connectors.
Eventually in 2016, AtariAge user ivop produced a circuit board to make them, he produced two runs of the boards and then stopped, and no one seems to have made them since.