What's new on „retrocmp“?


In regular intervals I will show one of my photographs on the homepage to lighten up the technical content a bit. So don't be surprised!

Picture of the Day


30th Oct 2020. Update: Exploring the low-level structure of an IBM floppy disk.

IBM MFM Floppy Format

24th Oct 2020. Examine the BASF CE alignment diskette with the KryoFlux.


28th Oct 2020. A quick test: Even a BASF CE alignment disk can be read perfectly with the KryoFlux. This alignment disk can be used for both 48 and 96 tpi, single or double sided drives. Exactly at the defined tracks, very characteristic patterns appear. All other tracks are not formatted. To be continued ...


25th Oct 2020. Examine the standard IBM MFM track format with the KryoFlux heatmap graph.


24th Oct 2020. Examine an alignment disk with the KryoFlux.


24th Oct 2020. Fixed a few dead links to 8 inch drives / General issues.

23rd Oct 2020. Duplicating a 8 inch floppy with a KryoFlux.


21st Oct 2020. MASMENU: The Master Menu for the Kaypro 10.


17th Oct 2020. Heise c't Retro 2020: This is a very pleasant surprise. In the current issue of c't Retro 2020 this website is mentioned several times (page 63 and page 66); in connection with the operation of 8 inch drives on a PC, FM compatible floppy controllers and the CompatiCard I!

c't Retro 2020

17th Oct 2020. Update RC2014: The Floppy disk controller from Dr. Scott M. Baker / BOM - Mouser.


10th Oct 2020. Update: File exchange between DOS and CP/M.

9th Oct 2020. Update: Using KERMIT on my Kaypro 10.

8th Oct 2020. Today I have brought my FAVICON's up to date. The basis is a hard-sectored 8 inch floppy disk with 32 sector holes plus one index hole.

Also on smartphones (Apple, Android) the corresponding icons should now appear.


2nd Oct 2020. UniForm for the Kaypro, Epson QX-10, Micromint SB180, Morrow MD3

UniForm for CP/M

26th Sep 2020. My Kaypro 10 after the maintenance. I exchanged the loud Seagate ST212 for a NEC 5126A and the Shugart 455A for the Mitsubishi 5426A. Furthermore I replaced three interference suppression capacitors (RIFA) on the power supply unit.

This is a German version with CP/M 2.2 (GMv3.20K10F) and a German keyboard. Here is the link to part 1 of my Kaypro series.

Kaypro 10
Kaypro 10

21th Sep 2020. What the heck are USER AREAS?

Kaypro 10 USER AREAS

18th Sep 2020. Setting up (formatting) a Kaypro 10 hard disk drive

Kaypro 10 FORMAT

13th Sep 2020. Kaypro 10 / 8K EPROM Modification / 4K to 8K EPROM Adapter


28th Aug 2020. TEAC manuals and brochures

26th Aug 2020. What a cute 3" floppy disk drive: TEAC FD-30A


25th Aug 2020. Update: My testsystems and floppy stations.

24th Jul 2020. Transteque MFM controller: HC-100

Transteque HC-100

16th Jul 2020. 3.5" floppy disk drive: TEAC FD-35HFN


10th Jul 2020. Memory expansion card: AST Rampage 286

ast rampage 286

27th Jun 2020. Sometimes you win, sometimes the others lose! I just bought a Deluxe OptionBoard (DOB) on Ebay US for $13. One should not believe it. The seller did not know what he was offering. He offered the DOB as floppy controller! Now I just hope that it is still functional. It looks great on the pictures.

20th Jun 2020. 8 inch floppy disk drive: NEC FD-1165-FQ

backpack 162550

7th Jun 2020. Central Point Software: Deluxe Option Board - Exploring the low-level structure of a floppy disk with the Transition/Track Editor (TE)

backpack 162550

30st May 2020. Update Microsolutions backpack CD-ROM

backpack 162550

1st May 2020. My 80386DX (DTK PEM-2035, 20 MHz) is up and running with my DTK PEI-306 RAM expansion card (12 MByte) and Windows 3.1.

Windows 3.11

18th April 2020. Since the page about my computers (test systems) was outdated, here is a new edition with many new images: My testsystems and floppy stations.

floppy station

14th March 2020. The BASF 6128-C for the Commodore PC 10.

BASF 6128-C

6th March 2020. BabyBlue II (Microlog): Turbo Pascal 3.0, Wordstar 3.0 and Zork for CP/M 2.2 are running fine under PC-DOS 3.30. Even PIP works under DOS!

1st March 2020. The BabyBlue II Z80 card (Microlog) on my IBM PC 5150.

BabyBlue II (Microlog)

23rd February 2020. Recording Problems / Reading and writing 360K disks in 1.2M drives.

basf, 6106, LSI

16th February 2020. Polar D320 digitalic DRAM and IC tester.

16th February 2020. Siemens 9775 / BASF 6106 as external floppy disk drive. With power supply via the DB37 cable.

basf, 6106, LSI

13th February 2020. Updated the series about the BASF 6106; the LSI version. Now the jumper settings are clear!

basf, 6106, LSI

31th January 2020. The IBM PC 5160 16-64KB mainboard with Super PC BIOS v3.1

delta products, xor

16th January 2020. CompatiCard I extended by further revisions (images)

12th January 2020. Delta Products / XOR / reading 8" floppy disks (FM/MFM)

delta products, xor

6th January 2020. CompatiCard IV


30. December 2019. A lucky find! I bought a used but not properly working IBM XT 5160 (256-640) on ebay a few days ago. It was not expensive, but not cheap either. According to the description only the fan of the power supply turns. Today it was delivered. Hopefully the money was not thrown out the window!

And what can I say: The case is almost perfect (but dirty on the inside), floppy and hard disk controller are perfect, the IBM hard disk WD25 is quiet and has only two unreadable tracks. Power supply and mainboard I could not test yet, ... The purchase was worth the money!

IBM XT 5160 from ebay

8th December 2019. The PC-elevATor 286 is running fine on my IBM PC XT 5160.

YM2149/ AY-3-8910 Sound Card

10th November 2019. The YM2149/ AY-3-8910 Sound Card for my RC2014. Flynn's Arcade says hello.

YM2149/ AY-3-8910 Sound Card

8th November 2019. The Floppy disk controller for my RC2014 is soldered and works fine. The Layout is from Dr. Scott M. Baker and I ordered the PCB from Osh Park.

floppy disk controller

25th October 2019. Today arrived from the USA. I had to wait and search on eBay US for a very long time. But it was worth it! The book is well preserved and was not expensive at all. The shipping costs were the highest.

"Chilton's Guide to Kaypro Repair and Maintenance"

Kaypro Chiltons

13th October 2019. ZETA V2 with 8 inch floppy drive support!

12th October 2019. Yep! My ZETA V2 is running fine with my 8 inch NEC FD1165. It's really quite simple. I just needed a little bit to rebuild the new ROM (RomWBW) with the new floppy driver. Then just reburn/flash the ROM (GALEP-5) and that's it.


6th October 2019. RC2014: XMODEM works perfectly with 115.200 bps in combination with the RAM disk! (see Workaround part 3)

29th September 2019 / 22:08: Hooray! I didn't have time for pictures yet. My RC2014 works fine! There were problems only with the strange assignment of my FTDI-USB cable. I unplugged the connector and manually connected the lines to the dual serial board. It works!

Probably I set about 800 solder points and everything worked fine. I am speechless. I have never soldered before in my life!

27th September 2019. RC2014: Building my own Z80 Computer

25th September 2019. Hercules Graphics Card (GB101, GB102)

22nd September 2019. Setting up a hard disk with HDMAINT within CP/M-86 on an IBM XT 5160

9th September 2019. Using an external 5.25" floppy diskette drive with power supply through a DC37 connector/cable.

18th August 2019. Replacing the DOS-Format program: FDFORMAT

4th August 2019. 8 bit MFM NCL Controller: NDC-5027

30th July 2019. You need the ROM BIOS for the CompatiCard IV, version 1.05? Look here at downloads.

2nd June 2019. Since the page about my test systems was hopelessly outdated, here is the new edition.: My testsystems and floppy stations.

30th May 2019. MicroSolutions: Megamate 2.8 Floppy disk drive (3.5") with 2.88 MByte.

29th May 2019. My 386DX-AT with a CompatiCard IV is up and running with four floppy disk drives. A: - 8" (M2896), B: - 5.25"/360K, E: - 5.25"/1.2M, F: - 3.5"/2.88M (Megamate 2.8). The Copy II PC Option Board Deluxe is also connected between drives A: and B:.

28th May 2019. Update: Exploring the features of CompatiCard IV floppy disk controller.

26th May 2019. Hooray! The "Magic Five" are complete: Option Board Deluxe, CompatiCard I and IV, Kryoflux and Catweasel MK4 PCI.

25th May 2019. My Catweasel MK4 is up and running. Even with my 8 inch NEC FD1165. Tim Mann's software CW2DMK and DMK2CW works perfect.

23rd May 2019. Emulation of floppy disk formats: CP/M to DOS interchange

12th May 2019. Emulation of floppy disk formats: SuperCopy

11th May 2019. TEAC FD-55 Series: FD-55E

10th May 2019. Data recording - from 'Single Density' to 'High Density'

1st May 2019. HBASIC (Hercules Graphics Card): HBASIC

26th April 2019. TEAC FD-55 Series: FD-55A

24th April 2019. 8 inch floppy disks: Single sided, double sided, flippy disk

12th April 2019. TARBELL BASIC: Source code found on old 8 inch floppy disks (1978/79)

7th April 2019. MicroSolutions: UniDOS

5th April 2019. MicroSolutions: UniForm-PC

4th April 2019. The Three Musketeers: CompatiCard / UniForm / UniDOS

30th March 2019. Update: My CompatiCard PC (286 AT) / My CompatiCard works only with DOS 3.20 not with 3.30!

29th March 2019. 8 bit MFM Western Digital Controller: WD1002S-WX2

26th March 2019. Disk drive speed (RPM) How fast does my floppy spin?

23rd March 2019. An odd 5.25 inch floppy disk drive: BASF 6106 (Siemens)

9th March 2019. 8 bit MFM Western Digital Controller: WD1002S-WX2A

Furthermore I replaced the fan in the power supply for my IBM PC 5150 today. I wrestled with myself for a long time, but the old fan was so loud that I replaced it with a quiet one. What a heavenly silence now!

28th February 2019. Memory expansion card: KOUWELL KR-513A

24th February 2019. Hooray! The "Magic Four" are complete: Option Board Deluxe, CompatiCard I, Kryoflux and Catweasel MK4 PCI.

23th February 2019. CTT Munich, IT-803 / 8 bit MFM hard disk controller from Germany

21th February 2019. Links updated / Malcolm Macleod: Floppy Disk Imaging

8th February 2019. Information about the Mitsubishi M4854-342M / Jumper settings, manual

17th January 2019. TEAC FD-55F running under PC/MS-DOS? (2M-XBIOS)

16th January 2019. East meets West - DDR (GDR) DIP RAM in IBM PC (U2164D C15)


28th December 2018. How do I transfer files from a modern computer to an old computer?

27th December 2018. Memory expansion card: IBM 256KB MEMORY CARD

26th December 2018. Running CD-ROM via the parallel port

2nd December 2018. I have updated the page about my My CompatiCard PC (286 AT). Among other things I have also described the program UNIFORM in connection with the CompatiCard. Finally I "quickly" created an 8 inch system disk with MS-DOS 2.11 for the NEC APC! You won't believe it, but I can actually run some programs on my IBM compatible PC under MS-DOS 3.20!

7th November 2018. Running CP/M-86 on an IBM PC

7th November 2018. Today my new "old" Option Board Deluxe arrived. I also bought it for little money on eBay. The description said used, but while unpacking it I saw that this board has never been plugged into an ISA bus connector before. The gold contacts were absolutely flawless! A first test. The card works perfectly! The complete package consists of the option board, the original manual and the original diskette with Transcopy V5.18. I miss the words!

Quick test: The Option Board Deluxe is not compatible with the CompatiCard I. To be continued.

4th November 2018. How do I import an old Word 5.5 *.txt file into modern text processors (i.e. OpenOffice) and covert it into a *.pdf file?

31st October 2018 Short info on the fast: With my IBM 5150 board and the ROM cassette Basic I actually wrote a short basic program and was able to save it via the cassette connection on a cassette. Awesome!

20th October 2018. Part 3: My CompatiCard PC (286 AT)

17th Oktober 2018. Links updated

14th October 2018. Exploring the features of floppy disk controllers.

Suddenly there was a loud bang. The blown capacitor

6th October 2018. I bought a CompatiCard I on ebay for little money. Awesome! This card is really a versatile floppy disk controller. This controller supports 8 inch drives with the original 77 tracks under MS-DOS. No tricks are required.

10th July 2018. Kaypro: About revisions and versions of the Kaypro family.

16th June 2018. Kaypro 10: Installing a new CP/M Version (2.2H) with the help of eight reload or autoload disks. I will report in more detail soon.

A brief outline. The Don Maslin Archive lacks the 8th image disk (k10hald8.td0)! Have a look at the submit file RELOAD.SUB (USER 0: k10hald1.td0). I downloaded all 8 Teledisk images (*.td0) from: www.mrynet.com.

As far as I can tell, both 2.2H image reload versions (Don Maslin / mrynet) are the same. The second line of RELOAD.SUB says: "last modified 9-14-84 rwb".

2nd June 2018. The Kaypro 10 arrived. CP/M 2.2F, one hard disk 10 MByte and a floppy (390 KByte). Awesome!

25th May 2018. BASF 6106 / revision of the website

20th May 2018. The site retrocmp.de is now "secure": https://retrocmp.de

5th March 2018. BASF 6106 / revision of the website

3rd March 2018. www.retrocmp.de is online