24 Mar
2006
24 Mar
'06
3:04 p.m.
Speaking of emulating RL0{1,2} drives, if I wanted to
attach some sort
of drive emulator to the big fat cable attached to the RL01 drive,
where would I get specifications on the signals in the cable?
AFAIK there never was a published specification. You'll have to work it
out from the printsets and the RL01 technical manual. It's not that
complicated, I worked out enough to make a drive exerxiser <mumber> years
ago.
From what I rememebr, you have raw data signals, write
gate, etc. The
drive will complain if you assert write gate at the wrong time (e.g.
during the servo burst time). There's also a serial clock/data signal
set which sends head-movement commands from the controller to the drive
(you send the number of cylinders you want to move to, and the
direction). and reports drive status back to the controller.
(Yes, I'm still thinking of how to emulate expensive things that may
die so I don't have to kill them by operating them :-).
Why bother to run a classic computer at all, then? Seriously, the drives
are as much a part of the system as the CPU is.
-tony