Last revision of this page: February 5, 2025

I have tested the CompatiCard controller with my 8 inch floppy disk drive NEC FD1165. It works fine. I have no problems in formatting a floppy disk with 250KB (FM) or 1.2MB (MFM) under DOS. Awesome!

As I mentioned before the CompatiCard I supports a variety of formats, see the figure below.

8 Inch Double Sided

A big one though! As you can see in the figure above, the CompatiCard supports two 8 inch formats (1.2MB and 250KB). As far as so good. I have formatted a disk with 1.2MB and checked it with Norton Diskinfo (DI). The formatted floppy has 16 sectors per track with 512 bytes per sectors. Oops! This are NOT the original MS-DOS 8 inch parameters; they must be 8 sectors per track and 1024 bytes per sectors! That's odd.

The media descriptor should also be FEh. But it is F9h, like the descriptor for 5,25 inch and 1.2MB! Now also the last column (see figure above) takes on a special meaning. The 8 inch ccformat /1.2 has NO official DOS Version! That sucks!

One day later. Those who can read have a clear advantage in life! My fault.

Have a look at the manual at chapter 3.5.1: "If no DOS version number appears next to a format, it means the format is unique to CCDRIVER and will not be readable with other software packages. These formats were included for people who wish to use the full capacity of their drive."

That's a disappointment for me (but only for 8 inch floppies). I have no idea why the controller/ccformat works with 512 bytes per sector and not with 1.024. The 8272A datasheet (see below) explicitly mentions that the controller can write 128, 256, 512 and 1.024 bytes per sector! Then why use 512? UniForm-PC can use in combination with the CompatiCard 1.024 bytes per sector!

By the way. Have a look at Tim Patterson: All Those Floppy Disk Formats ...

The 2nd 8 inch format with 250KB is correct. I also checked it with Norton DI: FEh with 26 sectors per track and 128 bytes per sector. Perfect!

According to the manual the CompatiCard also supports CP/M formats for 8 inch drives. But for this the program Uniform-PC is needed. This program is also from Microsolutions. With some patience you can find version 2.17 on the internet.

Conclusion

Even with the CompatiCard it is NOT possible to read or write the original 1.2MB 8 inch MS-DOS floppy format (77/8/1.024). Only the 250KB format (77/26/128) is supported. Too bad!

• CompatiCard I+II (1990) (5,5 MByte)
• Intel 8272A Datasheet (1986) (3,1 MByte)

• Part 1: CompatiCard I
• Part 2: Testing the 8 inch floppy drive options
• Part 3: My CompatiCard PC (80286 AT)
• Part 1: CompatiCard IV