9 Jun
2007
9 Jun
'07
10:53 a.m.
On Thursday 07 June 2007 01:07, Fred Cisin wrote:
On Wed, 6 Jun 2007, Roy J. Tellason wrote:
Ok...
So Dave, what's the deal with those oddball
5.25" drives? I'm
remembering vaguely some that were 96tpi, and one (?) that was
supposedly 100tpi...
Dave is testing the FDC, not the physical parameters of the drive. 96tpi DSDD was common briefly, but was never used in
the PC, except for
the PC-JX. To the disk controller, it is the same as a 3.5" "720K".
Teac 55F, Shugart 465, Tandon TM100-4, Mitsubishi 4853, etc
Micropolis came out with a 100tpi (77 track) 5.25" drive. It never really
caught on. Tandon made a replacement drive for that - TM100-4M.
I *think* that CBM used one in one of their boxes too, maybe the 8050? It's
been a while so I'd have to double-check that to be sure...
With a few exceptions, the 96tpi formats cqan be done
using a 1.2M drive.
Teac 55FG is deliberately intende3d for both "720K" and 1.2M use.
The only exceptions would be drive where the stepper switches to double
stepping when in "low density" mode, or using a 250K or 300K data transfer
rate.
Noted.
--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, ?a critter that can
be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin