CDC 9429 Floppy maintenance manual

Fred Cisin cisin at
Sun May 8 16:32:08 CDT 2016

> It would have at least had to be the SA400-L, since the SA400 was 35 track, 
> and PC-DOS, from the get-go, used 40 tracks.

Or [trivially] patched.  Either done right, or kludged by putting a 
non-existent file in the directory occupying tracks 35-39.

There were some strange patches in the early days!

PC-DOS 1.00 was single sided only, but the FDC supported double sided, and 
double sided drives were very available.  There was a patch being passed 
around that would permit installing a double sided drive, and the second 
side would be treated as though it were an additional drive.  I never got 
around to trying that with 4 drives installed, . . .
Does anybody know what the actual origin was for that patch?

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