Post by Ralf Kiefer Post by Anthony Ortiz
Not sure why she's unable to read the keyboard when the accelerator can do it.
How long does the keyboard controller need for his internal boot
process? This chip is incredible slow compared to the main cpu. The
frequency is 50kHz.
Fundamental question: is the keyboard encoder software/microcode based?
Why did Apple software guys take the apple keys (game port! not keyboard
encoded) to give the user the choice to start the hardware test (in the
Other details: the keyboard encoder 3600PRO doesn't use the /Reset
signal from the mainboard. This chip generates an own internal Reset
after powering up. Once(!) after power up. Also the 3600PRO needs +5V
and(!) -12V. If the power supply won't be able in generating stable -12V
the 3600PRO won't start reliable.
I've always guessed that it wasn't the initial keypress of ESC that was
detected, but the auto-repeat ESC that comes after...
The encoder undoubtedly takes many milliseconds to reset, as it takes
several milliseconds to denounce a key press.
I expect that accelerators sensing the ESC key wait (during their
initialization) for a good fraction of a second before reading the
BTW, the 3600PRO is a (slow) hardware state machine, not a microprocessor.
At the time, microprocessors used too much silicon for an inexpensive
keyboard encoder. Wow, -12v! Must be an old process, too!
-michael - NadaNet 3.1 and AppleCrate II: http://michaeljmahon.com