"intelligent" disk drives

[Ethan Dicks]

On Thu, Nov 15, 2007 at 05:14:34PM -0800, Geoff Reed wrote:
> the C= disk drives were pretty much all smart drives weren't they?

Yes.

>  the big dual drive units had a controller card in them that was
> basically a small computer (IIRC)

"Controller card" might not be the best term, but yes, there was a
one board inside with one or more 6502-family microprocessors
(depending on the drive model).  Older, dual drives tended to have
a couple of processors (6504s were common) with a few K of shared
memory; newer drives tended towards one microprocessor (a full 6502
was common), with a software scheme to simulate the multi-processor
model of the older drives.

The older, dual drives also had one analog board for both drive
mechanisms.  Newer drives had the analog circuitry on the mainboard
with the processor. 
 

-ethan

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Ethan.Dicks at usap.gov            http://penguincentral.com/penguincentral.html