8 Dec
2001
8 Dec
'01
2:18 p.m.
see below, plz.
Dick
----- Original Message -----
From: <UberTechnoid(a)home.com To:
<classiccmp(a)classiccmp.org Sent: Friday,
December 07, 2001 9:33 PM
Subject: Re: Shugart hard disk info
IIRC, the Q20xx series had 512 cylinders and 2,
4, or 8 heads. I may yet have
a data sheet for that series, as I have one or two of each model, still.
> The q2020 is an 8" 20mb unformatted
drive which yields 16mb (more or less)
> when formatted and has a 40ms average seek time.
> Mine had an aluminum cased ps bolted to it
and the drive stood on it's
> side.
> Regards,
> Jeff
<snip
Kinda sounds like a Quantum Q2020. I had one with a
sasi board mounted on
it back in 93'. Has a smoked plastic mech cover and a whole bunch of
warning stickers indicating it can remove digits if you dink with it while
open? I used a CSS Black Box for an interface. Sasi drives (and most scsi
bridge controllers) require specific formatting code. Also, iirc, sasi
devices required a dos-level bad sector map of the drive. In other words,
the dos you use scans the drive and creates a file occupying all the bad
sectors detected. The hardware didn't do that as with most (all?) scsi
drives/bridge controllers.
Shugart also made drives fitting this description, though I don't believe the
Shugart drives extracted the clock for you as ISTR the Quantum drives did. Both
drive types had a 4.34 MHz data rate and a 3125 RPM index rate, though.
The bridge controllers didn't do the media flaw or the bad-sector management for
you. The drive maker sent a defect list with the drive and, since the format
was up to the controller, and the number and size of sectors were for you to
choose, in some cases, they couldn't do bad sector mangement because that was
your job via the system software and utilities. Since the bad spots fell on
different sectors with differing sector sizes, the controller couldn't know in
advance where the defects lay.
As I recall, the q2020 has the same geometry as the Seagate st225
(620/4/17).??