Micro Solutions / CompatiCard I / (2)


Testing the 8 inch floppy drive options

<-- Back to Part 1: The versatile floppy disk controller

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 disc with 250KB (FM) or 1.2MB (MFM). Awesome!

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

CompatiCard I
CompatiCard I: Types of drives and formats supported

8 inch double sided

A big one though! As you can see in the figure above the CompatiCard supports 8 inch floppies with 1.2 MB and 250 KB. As far as so good. I have formatted a disk with 1.2 MB 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 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 1.2 Mb! Now also the last column (see figure above) get's it's special meaning. The ccformat for 8 inch /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 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 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 ...

DOS 8 inch parameters
The official DOS 8 inch parameters (KB Q75131)

The second 8 inch format with 250 KB 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 the 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. I have tested Uniform-PC with a 5,25"/360 KByte floppy and a Kaypro 10 disk. It works fine!


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

I have also tested the Compaticard I (as 1st controller) with the programs IMAGEDISK and TESTFDC by Dave Dunfield. It doesn't work at all!

Documents and information

My series about the: Micro Solutions CompatiCard I

--> Click here for Part 3: My CompatiCard PC (286 AT)