17-12-2020, 04:12 PM
The BEETHOVEN uses a General Instruments AY-3-8510 Programmable Sound Generator.
This IC contains two 8 bit I/O ports of whose pins are not presented to the consumer in its casing.
Only the top 5 bits of these I/O ports are useable. The other 3 bits are used for Microbee to BEETHOVEN interface.
The original idea was that two 4 way joysticks with a fire button could be connected to it.
That didn't happen thus you can't play a game using joysticks and the BEETHOVEN simultaneously from the user port
The standard driver as described in the manual supports only writes but it can be adapted to perform both reads and writes.
Like the Starnet, there was a dongle developed to connect the user port to two standard DB9 Atari type joysticks but it was not released in favour of having DB9 Atari type joysticks having their connectors cut off and replaced with pull up resistors and a DB15 plug and being sold as the "microbee" joystick.
This IC contains two 8 bit I/O ports of whose pins are not presented to the consumer in its casing.
Only the top 5 bits of these I/O ports are useable. The other 3 bits are used for Microbee to BEETHOVEN interface.
The original idea was that two 4 way joysticks with a fire button could be connected to it.
That didn't happen thus you can't play a game using joysticks and the BEETHOVEN simultaneously from the user port
The standard driver as described in the manual supports only writes but it can be adapted to perform both reads and writes.
Like the Starnet, there was a dongle developed to connect the user port to two standard DB9 Atari type joysticks but it was not released in favour of having DB9 Atari type joysticks having their connectors cut off and replaced with pull up resistors and a DB15 plug and being sold as the "microbee" joystick.