Last revision of this page: February 5, 2025

I've been looking for this floppy controller card for over a year. Now I got a CompatiCard I (Rev B). This card is really a versatile floppy disk controller.

The previous sentence must have been written in 2018. It is now the year 2025 and I am in the process of selling many things. It's getting too much. I already sold a CC I in 12/2024. Another one is still waiting for its new owner.

Revision C already looks somewhat more optimized than revision B.

Update 2020-01-15: Power supply

Attention, the cards from around 1986/87 differ in one important point from those from around 1989 and later. On the former the connector P4 is without power supply, on the later ones with current (+12V, +5V) on lines 1 and 2! Please refer to the manuals below (Tab 5-1) and have a look at Revisions C and D.

The jumpers JP4 and JP5 (Rev D) were not mentioned in the manual from 1990!

See manual page 5-1: "CompatiCard uses the 765 or 8272 diskette controller chip to achieve compatibility with the IBM diskette controller." Follow this link to the original IBM diskette drive adapters.

The CompatiCard I supports a variety of formats, see the figure below. The /360 format is also supported by 3.5" drives ab CCDRIVER Version 1.2x.

First time I installed the CompatiCard in an AT compatible 80268 motherboard as the primary floppy disk adapter. The operating system is MS-DOS 3.20. As floppy drive A: I have a TEAC FD-55BV (360 KB) and as drive B: a TEAC FD-55GFR (1.2 MB). Both drives are installed with one twisted 34 pin cable at the plug P2. In the BIOS both drives are correctly set. The DOS startup process "sounds" normal as ever.

But! Without installation of the CompatiCard software (ccdriver.sys) only drive A: (360 KB) is usable. Drive B: (1.2 MB) is visible, but the logical 1.2 MB format is not recognized. Only after installation of the driver the 1.2 MB drive is recognized correctly and can be used.

Then I exchanged the 1.2 MB floppy disk drive for a 360 KB drive. See that, the access also works here without the CompatiCard drivers. In other words, the CompatiCard only supports 360 KB drives by default. For all other formats the CompatiCard driver must be installed.

See manual, page 1-1: "CompatiCard can be used as a direct replacement for the standard IBM floppy disk controller card used in the PC and XT. CompatiCard is NOT a replacement for the primary foppy disk controller in an AT type machine."

Unlike the CompatiCard IV (CC4), the CC1 is not an AT type controller. For this reason it cannot be used with the ImageDisk program with HD (1.2M, 1.44M) and 8" drives. The CC1 has a very special way to set the data transfer rate. This method is not the usual PC disk controller standard. ImageDisk uses the IBM PC AT standard.

With one CompatiCard you can operate four physical floppy disk drives. In total even four CompatiCards are possible, i.e. you could operate 16 real floppy disk drives in one PC! Of course you may argue about the sense of 16 floppy drives! For example, a multifunctional copy station could be set up in this way. But who still has four CompatiCards today?

• CompatiCard I+II (1st Edition, September 1987)
• CompatiCard I+II (3rd Edition, March 1990)
• Notes for Micro Solutions CompatiCard Users (July 1992)
• Notes for CompatiCard II Software Version 2.X
• Intel 8272A Datasheet (1986)

• Vintage Computer Federation - Forum: Rev. A Microsolutions CompatiCard I Errors - Not working or just not compatible?

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