On October 4, Ethan Dicks wrote:
> I thought that it specifically _was_ the -1. I _think_ I have a DEC-
> badged RD-32 (ST-252-1) from a Pro380 VAX 8530 console, but I might
> be mistaken. Maybe they got what they could get in later years.
Probably so.
> > The ST251 had an average access time of 40ms (if memory serves) and
> > the ST251-1 was 28.5ms.
>
> That sounds right. Stepper motor vs. voice coil. (The ST-225 was
> something horrible like 65ms or more; I used to think seek-time didn't
> matter much on a micro, but when I went from 65ms to 28 on my Amiga,
> _wow_!)
The ST251-1 is a stepper drive also, believe it or not. They actually
built a stepper positioner that achieved 28.5ms. Back when it was new
I heard something about them having patented it or something.
The ST225 was indeed 65ms...scary slow. It made a great distinctive
"peep-peep" sound, though...which I liked even more than the [still
rather cool] "chirp-chirp" sound of the ST251 and ST251-1. :-)
I believe the first voice-coil drvie in that family was the ST-4096,
but I'm not positive of that. That was one nice drive.
-Dave
--
Dave McGuire
Laurel, MD
Received on Thu Oct 04 2001 - 22:01:30 BST