"Barn" finds - Victor 9000,

Tony Duell ard at p850ug1.demon.co.uk
Fri Nov 16 18:18:25 CST 2007

>  Be advised the Vic formats a DD disk to about
> 1.2megs, so it is a highly proprietary format. And

The Sirius/Victor 9000 disk controller is _strange_. Not suprisingly, 
giving its origins, the data circuitry is very similar ot that in a 
Commodore 8050 or similar,  it is, of course, a GCR encoded unit.

The data rate is constant (unlike an 8050), but the spindle speed changes 
(I thrink there are 16 possible speeds), giving an apporxximation to CLV 
recording as the head moves to different tracks. There are more sectors 
packed onto the outer tracks than the inner ones.

> even the DOS is customized for it's hardware. Good

That is not suprising. About the only thing that's common between a 
Sirius and an IBM PC is the processor. 

IIRC, the Sirius could run (at least) MS-DOS, CP/M-86 and the UCSD P-system.


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