My CompatiCard PC (286 AT)<-- Back to Part 2: Testing the 8 inch floppy drive options
In part 1 I still had a configuration with the CompatiCard as 1st and only FDC in an AT system. That was not correct! Now I rebuilt the system and added a 2nd floppy disk controller. I also added two more floppy disk drives
Today I just wanted to update the DOS version on my CompatiCard PC from 3.20 to 3.30. Basically this is only a matter of one hour under DOS. Most of the time it needs for the backup. Finally I spent several hours with it and ended up back at DOS 3.20. Why? My CompatiCard I always crashes under DOS 3.30 (here PC-DOS) when loading CCDRIVER.SYS. Why? I don't know.
I am using version 1.27 and CCDRIVER.SYS crashes immediately when the driver is loaded. The NODMA option doesn't change this either.
Although there are versions 2.02 and 2.03 on the Internet, these are for the CompatiCard II. I installed both versions for testing purposes, they started without any problems, but I can't access my floppy drives. Too stupid. Finally I ended up with DOS 3.20 and version 1.27 again and ... everything works fine.
It was still fun, though. By the way, I tried the ROM diagnostic function of the AMI BIOS again. The ROM includes an interleave auto function. Works perfectly. Hard disk (ST225) and controller run flawlessly with an interleave of 1:1. The transfer rate is about 343 KByte per second. With an interleave of 2, however, it is only 200 KByte per second. According to the data sheet, the transfer rate for the ST225 is a maximum of 5 MBit or 625 KByte per second. Now then.
Today I tested the CompatiCard Version 2.02 under MS-DOS 3.20. Result: The driver CCDRIVER.SYS is installed correctly, but no access to the drives is possible. Before I had created the configuration file DISKETTE.CFG correctly and tested it under 1.27. As already mentioned above, my versions 2.02 and 2.03 are only intended for the CompatiCard II (CC2).
I have searched the internet for a long time, but there seems to be only version 1.27 for the CompatiCard I.
The mainboard looks simply great and is only minimally damaged by the leaking NiCd battery. The tracks were cleaned and sealed again.
Configuration, BIOS, etc.
- 286-BIOS (C)1989 AMI (with ROM diagnostic)
- 1,024 KB RAM
- MS-DOS 3.20
- Disk drives
- A: 1.2 MB, 5,25" / TEAC FD-55GFR
- B: 360 KB, 5,25" / TEAC FD-55BV
- C: 20 MB / Seagate ST225
- D: 1.44 MB, 3,5" / TEAC FD-235H
- E: 8" / Mitsubishi M2896-63
- F: UniForm (user-defined)
- FDC: WD37C65B
- HDC: WDC42C22
- FDC: P8272A
My favourite 16 bit controllers are the WD1003-MM2 and WD1006-MM2. They are fast and always work. Since I use several 16 bit computers, I can also exchange the hard disks without any problems. Sometimes I also use the -MM1 variant when I only want to connect a hard disk and no floppy.
Drive D and E are added via the CompatiCard driver. You don't have access to them without CCDRIVER.SYS. Drive F is user-defined by UniForm and added by UNIFORM.SYS. My default type is MS-DOS Standard [DSDD:8":DOS].
CompatiCard hardware configuration
Since I operate the two 1.2 MB and 360 KB floppy disk drives via the primary controller (here: MFM controller), the CompatiCard must be configured as a secondary controller. Quote User Manual: "CompatiCard is not a replacement for the primary floppy disk controller in an AT type machine.".
CompatiCard is not a replacement for the primary floppy disk controller in an AT type machine.
(User Manual, 3rd Ed., March 1990, p. 1-1)
I have set up the CompatiCard as a so-called third controller number (J1=A, J2=B, I/O Port: 360h-367h).
If you are not using CompatiCard as the primary AT controller, you may choose any of the three remaining address jumper settings. Pick one which works in your computer. The third (A, B) has been found to work in most cases.
(User Manual, 3rd Ed., March 1990, p. 2-1)
CompatiCard and UniForm software configuration
device=c:\...\ccdriver.sys /8,7,3 /9,4,10
UniForm software configuration
Use the CTRL-D keys to select the default format. Use the CTRL-I keys to format (initialize) a diskette in the selected format.
If you type the command "CCDRIVES" after the DOS prompt, you get the following message:
CCDRIVES Version 1.27
The following CompatiCard drives are avaliable:
Drive D: - 3.5 inch High Capacity
Drive E: - 8 inch
UniForm-PC Drive F set to: MS-DOS Standard [DSDD:8":DOS]
To my knowledge, this is the only way to operate an 8 inch drive with the original format of 77 tracks, 1024 bytes per sector and 8 sectors per track. You only need the software UNIFORM, a CompatiCard is NOT nessessary!
Norton DI-Disk Information now correctly specifies the disk parameters. Also the media decriptor is correctly specified with FEh! The "system id" indicates that this disk was initialized (formatted) with UNIFORM.
I forgot! For the operation of an 8 inch drive you need of course an appropriate cable. You have to make this yourself, it's not for sale! No plug and play! Look here: "Problem no. 2: The controller cable.
A few gimmicks
At bitsavers.org I downloaded the image of MS-DOS 2.11 for the NEC APC. On my test PC I copied the image with Dave Dunfields ImageDisk to an 8 inch floppy disk. While copying I noticed the floppy disk parameters: 1,024 bytes/sector, 8 sectors and 77 tracks! Then I selected the NEC APC 8" format with UniForm and ... see there ...
Notice anything? I have executed the CAT.COM file and it is actually executable! In other words: I was able to run a file for the NEC APC (MS-DOS 2.11) on my IBM compatible AT under Ms-DOS 3.20. But the program CAT.COM works only in connection with the 8 inch drive.
Another test. I copied the program CIPHER.COM to my hard disk C: and started it. This also works. I was able to encrypt a text file and then decrypt it again. You can hardly believe it!