The MultiJoy8 Interface
Harry Reminder has enough
joysticks to keep an octopus happy
Hello MyAtari friends!
This time I want to introduce another new device. It
is called the MultiJoy8 interface and with this, it
is possible for eight people to play together on an
Atari XL/XE with one joystick each.
The MultiJoy8 interface
is attached to the computer with two joystick extension
cables (Sub-D cable) at the joystick ports. Eight connectors
are built into the interface for the joysticks of the
(Raster) has made two programs for the MultiJoy8 interface.
The interface is based on an idea of the Atari-Club
Prostejov. The two programs are Cervi and Multris. Cervi
is a variant of Snake or Tron for up to eight players.
Multris is a simultaneous Tetris for which up to four
players can take part. Both programs are freeware and
are published on the ABBUC magazine diskette number
The wiring diagram of
the MultiJoy8 interface was also printed in the ABBUC
magazine. Andreas Magenheimer (Charly Chaplin) had already
submitted a detailed description of the programs there,
too. He also requested for the production of the interface
(by the RAF) once again. Because of the demand of some
other interested people before, I have already promised
the production. So I started to rebuild such a device.
Cervi is an exciting game.
The more players join the game the bigger
their fun. The computer will handle the
non-human players, so there is a lot of
traffic on the screen.
It's tricky to navigate the
"worm" without collision. An extra
difficulty is to spot your own player on
the playing area when the game starts. Starting
positions are randomly chosen. Look out
for the number of your worm and the direction
Multris has the same basic
playing rules as the classic one-player
If a player "busts"
the others get extra points, that's the
difference. There is no interaction between
At the web site of Radek
Sterba is some additional information about the interface.
Unfortunately, I can't read Czech and so don't understand
any of it. However, assembler programmers can detect
the input of the joysticks with the small routine shown
The interface circuit
isn't as complicated as it appears at first sight. With
the joystick port 0 the status of each joystick is read
(direction and fire button). By the joystick port 1
the desired joystick is selected by means of a decoder.
The software apparently requests the condition of all
joysticks one after the other (time multiplex).
I have supplemented the
design with another feature: every joystick port also
receives the supply voltage provided by the computer.
So joysticks with auto-fire function or similar electronic
expansions will work.
I have created a layout
for the circuit and brought it to a standard euro circuit
board. This is necessary because of so many connectors
on it. Fortunately, there are project cases available
in electronic stores for this circuit board size. The
connection of the interface to the computer can be carried
out with the usual Sub-D extension cables.
I completed the first
device for the ABBUC JHV 2001. The visitors could
look at it and also try it out there. Regrettably, the
interest of the visitors wasn't very high. But I have
sold this first interface to a friend, The Gambler.
are only the two mentioned programs so far which work
with the MultiJoy8. I hope that even more programs appear
in the future. Whether and who will do this depends
upon the demand of interested people. If you love this
kind of game and would like more, address your wish
to Radek Sterba; perhaps he will surprise us with another
nice program for the interface soon.
Of course everybody is
also invited to write software for it. Maybe someone
is programming a game right now and can improve it for
up to eight players!