3.5" Altair CP/M
cclist at sydex.com
Sun Jun 3 16:37:57 CDT 2007
On 3 Jun 2007 at 13:11, Grant Stockly wrote:
>> TARBELL MINI-FLOPPY DIAGNOSTIC OF 8-1-80
> STANDARD VERSION 1.8
> 40 TRACKS 18 SECTORS
> What I would really like to do is find some way of connecting a 3.5" disk
> drive to the MITS hard sectored controller card set. This would give me
> the 300 or so K and allow me to run MITS basic off of the disk. Do you
> know anything about how to do that? Is it possible? Maybe with a PLD to
> deal with soft/hard sectored stuff?
So I was pretty close. The 1771 is keeping 128 byte sectors--which
figures. IIRC, the MITS controller required an 8" drive. Just
confugure a 1.44M as an 8" SS soft-sectored drive, use 26x128x77
format and enjoy the 250K that it brings you.
Yes, you could generate index pulses with something like a PIC (you'd
want to adjust the spacing to conform to the drive speed). But the
50K additional is, IMOHO, not worth it.
> I have not investigated anything yet so I am not sure what it would
> take. If its possible I'm sure I could get it done.
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