7 Jun
2007
7 Jun
'07
3:58 p.m.
On 7 Jun 2007 at 23:27, Tony Duell wrote:
AFAIK they were actually 80 cylinder drives, with the
normal 135tpi
spacing. Certainly on the double-head ones, HP formatted 77 user
cylinders, the last 3 were reserved for replacements for bad blocks, the
bad block map, etc.
...and there were also the 300 RPM 40 cylinder 3.5" DS2D drives at
67.5 tpi, used on a few CP/M systems as well as many inexpensive word
processors.
There were also some 600 RPM Sony 67.5 tpi SS drives. I think the
Preis boxes used them.
Cheers,
Chuck