24 Sep
2005
24 Sep
'05
10:32 a.m.
On 9/24/2005 at 9:52 AM Fred Cisin wrote:
Although not very solid, Epson was the only 67.5 TPI
3.5" drive that I
could ever find. (disk format of Geneva PX-8)
I believe I still have an original Sony OAD-1 drive (single-sided with head-load solenoid)
that was only 40 tracks. And I know I still have a couple of the competing 3.25"
floppy drives.
I remember about 20 years ago that TEC (NOT TeAc)
announced a
2.9" drive with a spiral track. (as well as some 720K 2.9" ones)
Is that what they were using?
Well, I'm holding one of the diskettes in my hand right now--it's labeled
2.8" and has no shutter over the access holes. The hub is a hunk of white plastic
(nylon?) about 3/4" in diameter with about a 1/4" center hole and a very small
hole for an indexing pin. These are "flippies"--each side has its own
write-protect punchout tab.
Does this sound like your 2.9" jobs?
There was also a Weltec 5.25" drive that ran at
180 RPM,
in order to do 1.2M with XT at 250K data transfer rate.
Ah yes--when it was cheaper to change the drive than the controller! AFAIK, almost all
5.25' 1.2M drives had some sort of dual-speed 300/360 RPM capability under the hood,
even if it wasn't publicized. Much like some 3.5" 1.44MB drives today.
The NEC approach always appealed to me--the same recording format and data rate across the
whole range 8"-5.25"-3.5".
The Dysan 3.25" was kinda neat. Dysan bet the
company that the
"shirt pocket" disk (3", 3.25", 3.5", 3.9") that would
succeed
would be the one with software availability. So, they overextended
themselves creating a software publishing/distribution company
providing MOST of the big popular software titles on 3.25".
'Course George Morrow said that the solution was to cut a deal with
the clothing industry to enlarge shirt pockets to 5.25" or even 8".
I've still got a couple of those drives--labeled "Shugart Venture" when
there were two Shugarts--one in the valley and one in the Santa Cruz mountains. Still
have a box of Dysan diskettes for them, too--but given the poor protection of the
recording medium, the LAST place I'd ever want to put on is in a shirt pocket!
My favorite weird drive was the Amlyn. It was before
the AT came out.
It used a "proprietary" 8 bit ISA controller that had a 500K data
transfer rate (could also be used for 8"). It used a cartridge that held
5 600 Oersted disks (total of 6M), with a few extra holes punched in
corners of the jackets, and could change disks from the cartridge under
software control. One of mine is now in Sellam's collection; NO idea
where the other one is.
I've only seen one of those--and it may have been at a WCCF--reminded me a bit of the
old NCR CRAM.
I've got a couple of the Drivetec drives with the dual-motor embedded servo
positioning system. One is the original 2.88MB model that was in the Kaypro boxes; the
other bears a Kodak nameplate and is a 6MB model.
Cheers,
Chuck