28 Jan
2014
28 Jan
'14
8:33 a.m.
On Jan 28, 2014, at 1:45 AM, Ethan Dicks <ethan.dicks at gmail.com> wrote:
...
RK drives do that - the most likely model you are to run across is the RK05.
The drives are identical from box to box, but the packs have slits cut in the
hub that result in 12 sectors for 16-bit hosts or 16-sectors for
12-bit hosts but
the same number of bits per track.
For those, you _must_ have the right packs, and you did occasionally
low-level format them (they use a "grated scale" optical positioner and
are hard-sectors and do not have any track or sector positioning
information written on the pack.
I assume diagnostics have a formatter in them somewhere. Failing that, the RSTS
initialization subsystem can format disks that support it, so a sufficiently old version
of RSTS that still has RK05 support can do this if you need it.
Incidentally, the 16 sector pack was also used in the IBM 360 model 44, which had an RK05
lookalike drive in the side of the main CPU/console cabinet.
paul