Re: CBM900 keyboard

From: Michał Pleban <*lists_at_michau.name*> Date: Fri, 18 Jul 2014 18:16:14 +0200 Message-ID: <53C9484E.9020803@michau.name> · lists_at_michau.name

Some more finds as I wait for the machine to arrive tomorrow. I fetched
the BIOS disassembly and here's what I found:

* The keyboard is definitely not PC-compatible nor Amiga-compatible.
This is because the scancodes are different from both PC XT/AT and Amiga.

* I am currently too lame with Z8000 assembly and the memory map of the
900 to figure out how exactly the keyboard data is transferred.

* The BIOS searches for lo-res and hi-res video boards on reset. If none
is found, it reverts to a RS-232C port for communication. This should
allow to run the machine without the monitir and keyboard.

Regards,
Michau.

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