On Mon, Mar 24, 2025, 2:59 PM Gregory Beat via cctalk <[email protected]> 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. > > There were Radio Shack and other computers (NCR, etc.) that used this > format (DSQD). > Thr DEC Rainbow too. I upgraded by RX50s to a pair of these. There are patches to 2.11 and 3.10b for 800k floppies. But it wasn't long after that that I got a 38MB hard disks and i went back to 400k floppies. The RX50s just had different padding between sectors so 10 would fit per track. All the other parameters were the same. If you didn't want to boot off the floppies, my IMPDRIVE package could read, write or format them. I pulled them out of storage during covid, but couldn't make them work reliably again. :(. Warner This corresponds to the capacity of the standard 3.5-inch double-density > (DD) drive. > > The 3.5-inch floppy disk format was supported since DOS version 3.2. > > Introduction of 3.5” drives and disks by IBM (mid-1980s) was one reason > why the 5.25 inch drives with 720 KByte storage did not find their way into > the IBM world. > > == > > Further in the above web link: > > Changing a Teac FD-55GFR drive to a FD-55F drive ... or, > How do I get my drive to spin at 300 RPM instead of 360 RPM ? > > gb
