And finally the end of the RL02 story

Charles charlesmorris at
Wed Nov 16 15:32:25 CST 2005

I made my own ribbon cable, removed the drive's input connector
and hooked everything up (making sure all the A pins of the Berg
connectors aligned with the stripe). Crossed my fingers and
powered up the system. Guess what... same error, Fault and Ready
lamps lit again, Load lamp out. Crap!

But all was not lost. Once again I checked for system clock and it
was not on the correct pins any more. I counted from each end of
the header cable (attached to the drive board connector) and
noticed the clock signals were on the 13th and 14th pin from the
end. That's M and N at the drive logic board end, confirmed by the
schematic, but the clock is on pins HH and JJ at the RL8A end
which just happens to be the 13th and 14th pin from the other end!

So - although the 40 pin cable is a "straight through" (pin for
pin), it turns out one end has to be reversed I flipped the Berg
connector over at the RL8A and everything now works :) It is
definitely inverted though, the black stripe on the ribbon cable
is in the "wrong" place for the RL8A end now.

I let it spin with the heads locked out for a while to remove all
the dust I probably stirred up. It operateds without any funny
noises (can't even hear it over the 8/A fans) and the Ready lamp
now lights after pushing the Load button and waiting for spin-up,
which is proper behavior. Then I keyed in the 10-word get-status
program from the manual and it returned the proper status words
(head over track 0, no error bits set) and can tell if the cover's
open, the write protect switch is pushed, etc.

Now all I need is software :)


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