Firstly the trap for the unwary. The power connector _looks_ like a
floppy drive connector, but it isn't. It's +5V (for the logic) and +24V
(for the motors). Be careful if you're swapping drives, etc.
Thanks for that :)
The drive mechanism has 2 boards. Most of the logic,
including an 8048
microcontroller, is on the top board. On the bottom of the drive there's
a second board that contains the motor control circuit. It talks via
QIC36 interface to a 2-board set mounted on the frame called the
Intellegent Controller. This contains another 8048 (some actually have a
daugtherboard with an 8035 or 8039 + EPROM in place of it) and a lot of
TTL to handle the data conversions. The microcontroller handles drive
control, etc, but it doesn't really do much with the data.
Clean the head as you suggested. Clean and reseat the
interface cables at
both ends. And try again.
You might be right about the multibus problem. Is there any way you can
run this thing with the framebuffer card installed?
Ok, I managed to work out how to get into the serial console with the
frame buffer installed, so that problem is eliminated, i've noticed it now
behaves correctly with the CBRQ jumper open (which is the way is should
be), which is something it wasn't doing before.
I'll give the heads a clean tonight and report back
Cheers
Karl
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Karl Maftoum
Computer Engineering student at the University of Canberra, Australia
Email: k.maftoum(a)student.canberra.edu.au