RL02 Disk Cartridge Problems

From: Patrick Rigney <patrick_at_evocative.com>
Date: Tue Dec 3 18:42:00 2002

Tony,

Do RL02's have a servo platter? I recall working with 300 and 600MB
multi-platter packs, on which one entire surface was reserved for "servo" to
help the head actuator establish track-to-track position. On many occasions
I'd see CDC drives load and then immediately retract heads and abort to
fault state if it couldn't read the servo platter, the net of which was
usually a 10-platter doorstop with a pretty plastic cover. ;-)

Patrick

> -----Original Message-----
> From: cctalk-admin_at_classiccmp.org [mailto:cctalk-admin_at_classiccmp.org]On
> Behalf Of Tony Duell
> Sent: Tuesday, December 03, 2002 4:03 PM
> To: cctalk_at_classiccmp.org
> Subject: Re: RL02 Disk Cartridge Problems
>
>
> > While I'm not Tony, I spent some time last year slaving over
> the RL02 (and
> > RLV12, RL8A) printsets, and I can tell you that the drive _doesn't_ care
> > what data is recorded on the disk. Fundamentally, the RL01/02 is a
> > fairly 'dumb' drive. Other than the sector marking magnets on the hub of
> > the disk, the drive is fairly undiscriminating. The only real circuits
> > between the read/write head and the ports on the back of the drive are
> > read and write amps (and write gate, etc).
>
> Be careful. The drive most certainly uses the servo signals recorded
> between the sectors. These are read by the normal heads/read ampifiers,
> and then passed to the drive logic board. If those are missing/mangled,
> the heads can't go on-track.
>
> But he drive most certainly doesn't try to do anything with the user
> data, including the headers and checksums. That's all handled by the
> controller.
>
> > A good check would be to listen for the heads to load into the pack. If
> > they're not loading, then there's no way that the data can be the source
> > of the problem.
>
> Agreed. Let's see what those heads are doing.
>
> -tony
>
>
Received on Tue Dec 03 2002 - 18:42:00 GMT