At the beginning I only had one test computer, see below. This has changed a lot in the meantime and I have more computers in operation now. All DOS systems can access my FTP server via network. Here is my latest overview (06/2019) with the very special features:


Pentium II

Desktop case

Pentium II

Benchtable case

*) You can use the 5.25" Mitsubishi M4854 as a direct replacement for a 8" floppy drive!


Open tower case


Flat IBM style case

IBM PC 5150

Original IBM case

IBM PC 5160

Open desktop case

Kaypro 10

CP/M 2.2, GMv3.20K10f, German version

Kaypro 10

CP/M 2.2h, English version

Floppy teststations

5.25 inch

Floppy teststation
Variant 1: Floppy teststation

Mitsubishi M4854-342, TEAC FD-55A, TEAC FD-55E, TEAC FD-55F, 2x TEAC FD-55B

Floppy teststation
Variant 2: Floppy teststation

QUMETRAK 142, Microstation MegaMate 2.8

Currently (Jul 2019) I am using variant 2 with my IBM XT 5160. With this teststation I can actually read and write nearly any DOS or CP/M 5.25 floppy format. As floppy disk controller I use a CompatiCard IV.

As drive A: I always use the FD-55B (360K). As drive B: I use the one that is currently needed. I always use the Megamate 2.8 as drive D: (720K, 1.4MB or 2.8MB).

8 inch

The pride of my collection. Actually there would be a Shugart 860, but I broke it myself, because I confused the self made 24 Volt plug with the 5 Volt plug. Stupidity has to be punished! Since then I have marked all my plugs with red and yellow.

Floppy teststation
8 inch floppy teststation

2x Mitsubishi M2896-63, NEC FD1165

I can connect the 8 inch floppy test station to both the 286AT and the 386DX-AT with the FDADAP interface from the DBIT.

I also have a Shugart 851 which ist not shown here.

... the following is outdated ... just as a reminder ...

Testsystem no. 1

# Hardware #

Computer PC-AT, ISA
Motherbord Appian OPUS/90 SX
BIOS Quadtel, Quadtel Corporation, 01/08/91
(with CTRL+ALT+S you get into the setup)
Controller Onboard HDD, FDD (each selectable with jumper on/off) The operation of an external MFM controller (ST-506/412) is thus easily possible.

The FDD controller (with the appropriate software; for example ImageDisk) is also able to write floppy disks in FM coding and one-sided!

The controller chip is a WD37C65CJM from Western Digital, here WDC '89. According to Dave Dunfield, the controller is compatible to 250 and 500 kpbs in single and double density mode (FM, MFM) but fails on double density with 128 byte sectors.

Prozessors Intel 80386 SX/16 und Intel 80387 SX/16
RAM 4x 1MB Simm, 30pin, 70ns, Hyundai (HY514400A / J-70 / 9608B Korea)
4x 1MB Simm, 30pin, 70ns, Siemens (HYB514400BJ-70 / Germany)
Network card 3Com EtherLink III 3C509B - C P/N: ASSY 03-0021-003 Rev A
Paketdriver: 3c5x9pd.com

# Software #

Operating system MS-DOS
Version 6.22 (de)

Testsystem no. 2

# Hardware #

Computer PC-AT, ISA
Motherbord Appian OPUS/90 SX
BIOS s.o.
FDD 0: uninstalled / FDD 1: uninstalled
HDD 0: Type 2 / HDD 1: Type 2
Controller Onboard HDD, FDD (switched off by jumper)

HFA-110W Multicontroller mit WD42C22-A Chip
(similar Western Digital WD1006V-MM2 or WD1003V-MM2)
The floppy disk drive is automatically detected by the controller.
Harddisks HDD 0: Seagate ST-225 MFM / 20 MByte / ST-506/412
HDD 1: Seagate ST-225 MFM / 20 MByte / ST-506/412
Prozessors s.o.
RAM s.o.
Network card s.o.

# Software #

Operating system MS-DOS
Version 3.20 (en), (Commodore PC I / 31.08.1987)
Testsystem Nr. 2
Testsystem no. 2 with two MFM HDDs

The experienced retro hobbyist will now, of course, say that signal cables, and in particular the data cable, are far too long for the MFM hard drives. Yes, that is correct, but I have not had any malfunctions so far. Even with too long cables, the overall system works well. No data bits have been struck during the transfer yet!

The MFM signal cable, like the floppy cable, has a twist, but ... The floppy cable has a twist on lines 10-16, the MFM cable has a twist on 25-29. Otherwise both have 34 lines.