[Info-vax] Question about IDE disks

[Michael Moroney]

JF Mezei <jfmezei.spamnot at vaxination.ca> writes:

>BTW, a very knowledgeable person has contacted me privately. It appears
>that IDE protocol is able to send error messages to the OS, but that the
>DQDRIVER on VMS doesn't do anything with them.

Judging from the speed of DQDRIVER on Alpha, I assume they also neglected
to put the drive in a mode faster than some default low speed mode.

>However, there appears to be at least an exception to this since the
>DQDRIVE is able to log an error when the system is being configured and
>it tries very hard to create a drive that doesn't exist. (if you don't
>have 2 drives in the system).

DQDRIVER also doesn't do the right thing here, by creating nonfunctional
drives (UCBs) in the IO database for nonexistent drives.  DKDRIVER doesn't 
create a nonfunctional DKA100:/DKA200: etc. if the only drive on the PKA: 
bus is DKA0:.

(I vaguely remember someone mentioning a reason for that behavior, but also
vaguely remember it as a not very good excuse)