Floppy Disk Drives / TEAC FD-55F / PC-DOS


TEAC FD-55F running under PC-DOS 3.30?

In my first article about the TEAC FD-55F I wrote that this floppy disk drive cannot be used in a IBM compatible computer. DOS only supports 360 KByte and 1.2 MByte floppy disks for the 5.25 inch drives. 720 KB is only available for the 3.5 inch drives.

Why then this article? Sometimes I am a bit persistent and I asked myself: "Is there perhaps a way? The answer is YES. All you need is a tiny little program called 2M-XBIOS.EXE. That's all.

The special feature for the 5.25"/720 KB drive lies solely in the following program line (CONFIG.SYS).


Drive B: is assigned the parameter 3 (720 KByte). After the restart you can format a DS DD 5.25 inch floppy disk in a QD flexible disk drive with FORMAT B:.

Size Number Comment
360 KB 1 DD
1.2 MB 2 HD
720 KB 3 DD
1.44 MB 4 HD
2.88 MB 5 ED

I couldn't believe it myself at first, but it worked. Of course you can't use the floppy disks formatted in this way on any other computer! It is also only about the principle.

Tested on my IBM XT 5160 with PC-DOS 3.30 and a standard floppy disk controller (UM8272A). You can download 2M-XBIOS at minuszerodegrees.net.

Note: With the '2M-XBIOS.EXE' trick, you can only use the double-sided TEAC FD-55F. The single-sided TEAC FD-55E cannot be used under PC/MS-DOS. This drive does not fit at all into the DOS world; only CP/M and other old operating systems.