On Fri, 06 Jun 1997 01:09:14 -0700 
 Nathan Gelbard <gelbard@ENGR.ORST.EDU> wrote:

 > I've got a MAXTOR 760mb ESDI drive I pulled out of a 
 > Apollo 4500 that I want to use. I plugged it into a 
 > HP 7958 disk box (ex 170mb Micropolis). I didnt
 > plug in the blinking lights, and -current thought
 > it was a 50mb tape drive <g>. Plugged in the lights,
 > and it was FAULT!
 > 
 > 	Now, I REALLY WANT to use this drive. I hate having
 > 3 120mb drives. Any chance I can fix it?
 > 
 > 	Thanx,
 > 		Nate
 > 
 > PS: could it be the controller card in the hp7958 box that
 > wont read it?

Yes, that's exactly the problem... the HPIB->ESDI bridges in the
HPIB disk boxes are expecting a certain disk type, with a certain
geometry.  You can't just drop in random drives...

Now, I think the controllers are all basically the same, save
an EEPROM, or something, that holds the information for the type
of disk that was installed in the box... although, I'm not 100%
certain... (I suppose I could pull one of my 7958s apart, but you
already have yours open, so I'll let you look :-)  Anyhow, if you
can find the beast, and figure out the format, you might be able
to fudge it...

Jason R. Thorpe                                       thorpej@nas.nasa.gov
NASA Ames Research Center                               Home: 408.866.1912
NAS: M/S 258-6                                          Work: 415.604.0935
Moffett Field, CA 94035                                Pager: 415.428.6939