Roy J. Tellason
rtellason at verizon.net
Sat Jun 9 12:53:04 CDT 2007
On Thursday 07 June 2007 01:07, Fred Cisin wrote:
> On Wed, 6 Jun 2007, Roy J. Tellason wrote:
> > 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
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
More information about the cctech