IDE knowledge anyone?

Oliver Lehmann lehmann at
Thu Dec 10 15:19:00 CST 2015

Chuck Guzis <cclist at> wrote:

> ABRT set in the error register basically indicates that the drive   
> isn't ready or that there's something wrong with the command.  You  
> may want to insert some debug code that displays exactly what's  
> being written to the drive registers.

Did that - echoed it out on serial line. But think about it - under
what circumstances I could write wrong data to the cyl/sec/head
registers that ANY other drive interprets correctly (I'm booting an OS
from other harddisks successfully)? If I would write wrong data into
those setup-registers I would also get errors from other devices,
My thinking was, that the drive does not interpret the data correctly.
Things like:

1 Low-High-Switch not "clear" enough to the drive to accept the data
2 Low/High-Indicating voltage near the limits and the drive has slightly
   broken stuff so if the voltage is  neart the limit, it indicates
   "forbidden voltage"
3 I'm to fast in asserting a signal and the disk can't pick it up that

2 -> i would have other errors as well e.g. sending identify command
also uses the same lines...
3 -> i already tried delays everywhere without success....

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