Victor 9000

From: Doug Spence <ds_spenc_at_alcor.concordia.ca>
Date: Fri Jun 20 06:53:27 1997

On Thu, 19 Jun 1997, A.R. Duell wrote:

> > Uh, I beg to differ about the Victor 9000 being the first computer to use
> > variable speed disk drives, as my CBM 2040 dual drive unit from 1979 does
> > this.
>
> No it doesn't (or at least the 8050 doesn't, and nor does the 1541 - I
> have service manuals for both of them)
>
> The disk turns at a constant speed. What changes is the speed of the data
> clock. The bits are sent faster for the outside tracks, so it can fit more
> sectors on said tracks.

Interesting. I had read that those drives were variable speed, but from a
much less reliable source than service manuals. Thanks for the
clarification!

> I never really saw the point of variable-speed drives. Changing the data
> clock is a lot easier, and probably faster (getting the spindle
> up-to-speed and locked at that speed takes considerable time).

Yup, you're right.

> --
> -tony
> ard12_at_eng.cam.ac.uk
> The gates in my computer are AND,OR and NOT, not Bill

Doug Spence
ds_spenc_at_alcor.concordia.ca
Received on Fri Jun 20 1997 - 06:53:27 BST