24 Mar
2025
24 Mar
'25
10:31 p.m.
On 3/24/25 13:58, Gregory Beat via cctalk wrote:
TEAC FD-55F floppy drives
https://retrocmp.de/fdd/teac/fd55f.htm
The TEAC FD-55F never appeared in the world of IBM compatible computers. Why is that?
Because it was simply superfluous in the DOS world.
The TEAC FD-55F is a double-sided 5.25 inch drive that can write 96 tracks per inch (TPI)
with 9 sectors per track. In other words, the capacity of a floppy disk is 720 KByte.
If by the FD55F not being used in the world of PC compatibles, perhaps
as to brand, but certainly not as to 96tpi double-density.
The Sanyo MBC-500 series comes to mind with various diskette options.
At Durango, the standard drive for Poppy was the Micropolis 1115-VI
full-height 96 tpi drive. I used one on my 5160 running PC-DOS 2.0--use
was mostly a matter of laying down a disk format--otherwise the drive
functioned as a 720KB drive without system modification.
There were other such systems in the PC-compatible world. It was viewed
as a benefit in competition with IBMs 48 tpi drive choice. The 96 tpi
drive was even common on several 8-bit CP/M systems.
When the official support by IBM and Microsoft for 3.5" DD support,
there was a difference in FAT and cluster size between IBM and Microsoft
MS-DOS. It hardly made a difference with the DOS 2 first sector
containing the DPB, but may have caused confusion in the PC-DOS 1.x world.
--Chuck