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Misc joystick interfaces

Apple Macintorsh

The joystick connection for Mac is on ADB port. ADB (Apple Desktop Bus(tm)) is a A low-speed serial bus used on Apple Macintosh computers to connect input devices (such as the mouse or keyboard) to the CPU. Apple ADB bus uses small 4 pin connector and the maximum lenght of the serial bus is 5 meters. ADB bus can supply total of 200 mA of +5V power to the devices connected to it. If the devices take more then the overcurrent protection will shut down the power feed.

Devices which connect to the ADB contain their own micro-processors, which handle both device routines and the ADB interface. There are 16 possible device locations available on the ADB. Each device can maintain up to four variable-size registers which may be read or written from the device over the ADB network using four available control commands.

Here is the pinout of Macintosh Quadra 700 ADB-port (4-pin minicircular connector).

            Apple Desktop Bus (ADB)
            -----------------------
            Pin Signal name Signal description

            1 ADB Data
            2 PWRON Power on
            3 +5v +5 volts DC
            4 GND Signal ground

If you want to start developing ADB interface devices, then I don't knwo where to start. Apple doesn't have an ADB starter kit. You can found some SDB bus technical information from OpenMac hardware references at http://www.macbsd.com/openmac/refs.html#adb. There is also some information on ADB bus at ADB Demo in ZBasic 5.0 & LS Pascal 2.0 page, Some information on books which have information on ADB-bus can be found at http://til.info.apple.com/techinfo.nsf/artnum/n4603.

Because Apple Macintosh joysticks use serial bus interface there is no easy way to convert them to other computer or to convert other joysticks to Apple Macintosh.


author: Tomi Engdahl