There are a couple of games for C-64 and the the 4-player adapter that are a lot of fun (e.g. http://www.protovision-online.de/hardw/ ... anguage=en).
I started thinking about how the adapter works and noticed that it is easily possible to extend the adapter for more joysticks.
Instead of multiplexing just between two Joysticks, with 8 I/O lines it just needs 5 inputs for the four directions and the fire button and 3 outputs to address the joystick you want to read.
I also always wanted to put some LEDs to good use, so I decided to add the 40 LEDs for all 8 Joysticks. That way, you can tell if somebody saying her joystick is broken is just making excuses.
Here it is:
After finishing my 8-player adapter I found out that there is already the MultiJoy8-Interface for Atari 800XL, but it requires two Joystick-ports that the Vic-20 doesn't have.
(It also lacks the pretty LEDs!)
Now I had 9 Joysticks connected to my Vic-20 (internal port & 8 on the interface) and needed a game for the next meeting.
Tron is simple enough, but could be tricky, because of the limited screen area and lack of enough different colors.
I finally settled on implementing a variation of Super-Amok for 9 players, using just a single room without exits and no robots.
Every player has 9 lives and the last player to live wins.
There is also a simple intro screen using the built-in font to display the game title and a scroller while playing "slow ride" by Daniel Kahlin (thanks!).
The game is rather simple, but fast paced and everybody including the kids had a lot of fun playing it.
I will release the game soon after some more polishing, but you need to build your own interface first to use it.
Or you could get MultiJoy8 and adopt it for the user port. And write more games for up to 9 players!
(EDIT: links changed to new project location)
