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
