READ THIS WARNING

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a photo realistic soccer ball as a planet in space with pink smoke and explosions, with 2 moons in the background, digital art

28th Dec 2024. Update: My new DOS floppy test and disk imaging system with a DTK PAM-0055I-E0 mainboard (with a Pentium 75). This mainboard uses the super I/O and floppy controller PC87306 by National Semiconductor. You can even read and write single-sided 8" CP/M floppies with 128 bytes/sector (FM).

Note: The DTK PAM-0055I-E0 motherboard does not appear in Dave Dunfield's well-known list!

16th Dec 2024. My contribution to the topic Friday the 13th: Kaypro - Kaycomp II.

14th Dec 2024. Reading, comparing Kaypro II CHAR ROMs and more.

12th Dec 2024. Update: The Shapiro-Thompson ROMs for the Kaypro II.

7th Dec 2024. Update: The Kaypro Family and Company.

5th Dec 2024. New: Kaypro - Kaycomp II.

30th Nov 2024. KayPLUS-83 on a Kaypro II 81-110A mainboard: Formatting a 3.5" Floppy Disk.

29th Nov 2024. New: Formatting a Floppy Disk on a Kaypro.

23rd Nov 2024. Update: How to Low-Level Format a Hard Disk With DEBUG and other methods like the AMI 286 BIOS.

23rd Nov 2024. Update: Seagate Hard Disks (MFM & RLL only).

17th Oct 2024. Kaypro update: Formatting a Kaypro Hard Disk Drive.

9th Nov 2024. Update: MFM Emulator for my Kaypro 4/84.

16th Oct 2024. Update: Kaypro versions and how it all began. General revision and review of references.

16th Oct 2024. Update: Kaypro Robie. General revision and review of references.
Even after the revision, I stand by my statement that there was a Robie with double-density drives for the European market, at least for the German market. But read for yourself.

7th Oct 2024. Lots of Kaypro updates: Information - 4K to 8K EPROM Kaypro 10 Modification - Formatting a Kaypro Hard Disk Drive - TurboROM - KayPLUS ROM - MFM Emulators

3rd Oct 2024. Update: MICROCode KayPLUS ROM.

28th Sep 2024. Update: I found a new Kaypro II (81-110A) modification. This mod changes the ROM size from 2K to 8K.

17th Sep 2024. Update: The origin of the 8" floppy disk format and DOS.

15th Sep 2024. New 8 inch drives: Tandon TM848-02.

25th Aug 2024. Update 8 inch drives: Testimonials - TexElec - 34 to 50 Pin 8" Floppy Adapter. Using it with two 8" floppy disk drives as A: and B:. I tested the adapter with a pair of Tandon TM848-02 and Mitsubishi M2869-63 disk drives.

23rd Aug 2024. Some new modern 8 inch drive (1st of 3): In the last 4 weeks I was able to purchase three 8 inch floppy disk drives on eBay US. And for very little money. Each drive cost less than $70. Plus of course shipping from the US to Germany and tax/customs. But even then it was still under $100 per drive. Today I tested the first of two Tandon TM848-02 drives. After a few teething problems, it works perfectly. Formatting, copying and reading with 22DISK works fine (CFMT, CDIR, DTOC, CTYPE). I used the 8" adapter by Joel Schmidt. ... 2 hours later. The 2nd TM848-02 works fine too. Great! Here too, teething problems.
According to my experience and observations over the last 6 years, a good working modern 8” drive costs between 300 and 400 EUR.

23rd Aug 2024. Update 8 inch drives: All 8" adapters currently known to me in one picture. Send me an e-mail if you have any questions. The adapter top left is by Joel Schmidt. You can buy it on eBay DE for 39 EUR; shipping included. This is a bargain!

4th Aug 2024. New: Noth Star Horizon S-100 boards including the HRZ-HD5 and HD5 power supply.

3rd Aug 2024. Update: How do I Install an 8" Floppy Disk Drive in an IBM DOS or Compatible PC?.

28th Jul 2024. Update: Added a real image of the Kaycomp II .

27th Jul 2024. Update: Images of the Hercules Text Card (courtesy of Valentine Pillow-Wilcox).

13th Apr 2024. Update: IMSAI history.

12th Apr 2024. The reason for developing the IMSAI 8080 (my correspondence with Joe Killian).

30th Mar 2024. Reforming four capacitors for an IMSAI 8080.

30th Mar 2024. Reactivating a TRANEX 4 3751.

27th Mar 2024. 256 BYTES: The ALTAIR 8800 font.

26th Mar 2024. My Altair 8800 in disguise. Running 24K CP/M 2.2b for Altair Mini Disk on my IMSAI with the Altair FDC+.

21st Mar 2024. Kaypro Micro Cornucopia: CLEAN PRO-CHAR.

17th Mar 2024. Configuring the ICC Gould 100-0062 for the Altair 8800.

12th Mar 2024. Today again 8 inch drives. Just tested the 34 to 50-Pin 8-Inch Floppy Adapter by Texelec. Works perfectly. Not to be expected otherwise.

29th Feb 2024. Configuring the Altair FDC+.

25th Feb 2024. Configuring the Solid State Music IO4 for the IMSAI 8080.

16th Feb 2024. New project: The High Nibble - building an IMSAI 8080 replica.

6th Feb 2024. Godbout ECONOROM 2708.

27th Jan 2024. Update: My new IMSAI Plexiglas top cover and the Wameco FPB-1 front panel. Fits perfect!

25th Jan 2024. Update: My new IMSAI Plexiglas shield and the Wameco FPB-1 front panel. Fits perfect!

23rd Jan 2024. Update: IMSAI PSU. Bleeding resistors and high frequency filtering.

22nd Jan 2024. Hunger for electricity: IMS 8K static RAM boards.

17th Jan 2024. My new IMSAI front panel bezels arrived today. They fit perfectly. The only thing missing for my working IMSAI (bottom right) is the Wameco FP-1 and then I'll create a new mask for it.

6th Jan 2024. My next project: The High Nibble: IMSAI 8080 replica by David McNaughton from Australia. I have the kit lying here on my shelf since month. It's time to put it together. Why a replica when you have a real IMSAI? Because it's fun and I'm looking forward to the GUI. This is simply brilliant.

When I bought this replica, I never expected to own a real IMSAI one day. That's how wrong you can be.

6th Jan 2024. Update: I ordered in December 2023 three 3D print IMSAI paddle switches. Today they were delivered. The result looks quite good. .

5th Jan 2024. S-100: IMS 16K Static RAM.

4th Jan 2024. IMSAI 8K ROM BASIC.

4th Jan 2024. Update: ROM Monitors (GWMON80).

4th Jan 2024. Update: Programming 2708 EPROMs.

3rd Jan 2024. Vector Graphic 12K PROM/RAM.

31st Dec 2023. Programming an 2707 EPROM with the Cromemco Bytesaver 8K and MEMON/80.

30th Dec 2023. "News from the Past." Yesterday I received another e-mail from Joe Killian. We are in regular contact. This time he told me about the reason for developing the IMSAI.

23rd Dec 2023. ROM Monitors (MEMON/80).

22nd Dec 2023. CompuPro Interfacer1.

17th Dec 2023. Update: Making your own 3D IMSAI paddle switches.

17th Dec 2023. Update: Checking and repairing the IMSAI 8080 frontpanel.

12th Dec 2023. Alignment tester and exerciser: Lynx 470

11th Dec 2023. Update Shugart 400: Stepper - Head Positioning

9th Dec 2023. North * Star - Micro Disk System.

5th Dec 2023. My 2nd IMSAI restoration project has started.

29th Nov 2023. New: IMSAI 8080 - Power Supply Units.

28th Nov 2023. Minor update: DEC RX180.

28th Nov 2023. Updates: Shugart 400 and Shugart 400L

26th Nov 2023. Minor update: IMSAI restoration page.

25th Nov 2023. Update: Booting a single-sided, single-density floppy (N* Horizon, MDC-A4).

17th Nov 2023. Update: North Star PSU & rectifier.

11th Nov 2023. Update: North Star Virtual Horizon by Dave Dunfield.

2nd Nov 2023. The Solid State PB1 Board.

1st Nov 2023. Today arrived a very heavy package. Christmas was brought forward, a Sol-20 computer.

30th Oct 2023. Mistakes are very important for the learning process, only you should not make the same mistake a second time, especially if the consequences can be severe. Therefore I have put together a basic check for my S-100 boards. I make this test with every new board I get.

29th Oct 2023. Update: Cromemco 8K Bytesaver and Programming 2708 EPROMs.

28th Oct 2023. Update: IMSAI back panels.

27th Oct 2023. A good floppy disk drive (COPAL Fujitsu M2551A) and hard-sectored floppy disks (HS10) for the N* Horizon are something nice.

21st Oct 2023. Update: IMSAI history - serial numbers.

21st Oct 2023. You are looking for North Star Horizon images (NSI format)? Have a look at here; by geneb of VCF.

20th Oct 2023. I'm so excited about this Sol-20 by Processor Technology.

16th Oct 2023. Update N* Horizon: A minimalistic Z80A Processor Board ZPB-A2. No PROM, no FRONT PANEL and no sockets. The main thing is cheap.

15th Oct 2023. Part 1 - My Cromemco 8K Bytesaver is reading a 2708 EPROM without problems. The next test (part 2) will be the programming of a 2708 EPROM; stay tuned.

3rd Oct 2023. Programming 2708 EPROMs.

3rd Oct 2023. Quad-Flop – 8" floppy adapter - by TexElec.

3rd Oct 2023. Quad-Flop – Four port ISA floppy controller - by TexElec.

3rd Oct 2023. N* Horizon: The issue with a short circuit in the -16V line and how to avoid it. Explained using the Cromemco 8K Bytesaver board.

23rd Sep 2023. N* Horizon: Using the Morrow DJ-DMA floppy disk controller with hard sectored disks.

21th Sep 2023. Kaypro II: The change from vertical to horizontal drives was made in 11/1982 due to obtain the FCC approval.

11th Sep 2023. Minor updates: Kaypro II, 81-110, drive fix mod.

11th Sep 2023. Minor updates: Kaypro II - The Son of the Ferguson BigBoard I.

10th Sep 2023. Do you need the correct jumper settings for the North Star Horizon ZPB-A2?

8th Sep 2023. Stephan Slabihoud's Retro Chip Tester Professional.

5th Sep 2023. Update: Reading real old 8" Sisyphus CP/M 2.2 floppies with 22DISK. Single-sided, FM+MFM and 48 sectors of 128 bytes. A challenge! But Chuck Guzis has solved the problem!

3rd Sep 2023. Minor updates: MicroSolutions Megamate 2.8 - CompatiCard IV.

3rd Sep 2023. Update: Floppy Disk Controller. Managing FM and 128 bytes/sector.

27th Aug 2023. Update: Using 8" floppy disk drives under PC/MS-DOS.

25th Aug 2023. Reading old 8" Sisyphus CP/M 2.2 floppies with FLUXTEEN, HxC and cpmtools.

23rd Aug 2023. Minor updates: FDFORMAT by Christoph H. Hochstätter. You can also use this DOS program for 8" floppies.

23rd Aug 2023. Formatting 8" floppies under PC/MS-DOS with 8FORMAT by Jozef Bogin.

22nd Aug 2023. Minor updates: My test systems.

22nd Aug 2023. Today, after more than two years, I put my 80286 VLSI computer through its paces. I use this computer as a test station for my 8" drives. I have connected the 8" drive to be tested as drive A: so that I can also boot from it. I use two floppy controllers here. One is the WD1006-MM2 and the other is the CompatiCard I.

21th Aug 2023. Update: New Shugart SA851. So new that not even the screw for the savety lock was removed; so really NOS and a bargain (130 EUR).

20th Aug 2023. My EPROM Programmer: Galep-5, Barlino II, HVEPROM project by Matthew Millman for MCM68764, MCM68766, 2704 and 2708 EPROMS.

20th Aug 2023. Minor updates: DRAM Tester by Stephen Vickers and Polar D320 Digitalic DRAM and IC Tester.

4th Aug 2023. I played around a bit with Bootstrap again today .

21st Jul 2023. How does DOS work again? Actually a stupid question. But after 12 months of Kaypro (2022) and 6 months of N* Horizon and IMSAI, I switched on my NoName IBM XT computer again today after 24 months at least. And thank God it still works. No tantalum capacitor exploded so far. I have to test and take care of some new old 5.25" floppy drives again and my new MatchPoint PC card by Microsolutions. With this it should be possible to read hard-sectored Northstar floppy disks!

17th Jul 2023. Reforming a Temple (95,000 MFD, 15V) capacitor. After my first test runs on Monday, I was not yet so convinced that I could reform both capacitors. In the meantime, five days have passed (21st Jun 2023) and I am very confident that it will work.

15th Jul 2023. The YAZE-AG emulator by Andreas Gerlich running on macOS Ventura.

14th Jul 2023. IMSAI 8080: Emulator and the z80pack by Udo Munk.

11th Jul 2023. Delivered today. A MatchPoint-PC card.

10th Jul 2023. Update: Installing the Homebrew and cpmtools on macOS.

8th Jul 2023. Update: Accessing files with CPMTOOLS on the N* Horizon.

8th Jul 2023. Update: Using different ports on the N* Horizon for console and file transfer.

7th Jul 2023. Minor updates: My series about the CompatiCard I & IV.

7th Jul 2023. I can not believe it. What a stroke of luck. A MatchPoint-PC card was offered on ebay France. With this card & UniForm-PC you can read NorthStar CP/M floppies! I will report.

30th Jun 2023. Update: Proc Tech 8KRA board.

30th Jun 2023. Update: 4 x IMS 8K boards.

25th Jun 2023. New: Reforming large old electrolytic capacitors.

17th Jun 2023. Well, the IMSAI 8080 or the front panel seems to work properly now. Before I continue there, I have to test a lot of new S-100 cards with my N* Horizon. This includes the MDC-A4 floppy controller. Yes, this is the original single-density (SD) controller. For this, I set up my first Horizon again, which has two internal and one external floppy drives.

15th Jun 2023. Update: IMSAI history.

12th Jun 2023. New, IMSAI 8080: Front Panel (CPA).

8th Jun 2023. As a replacement for my IMSAI 8080 front panel: TTL 7405 - 7231. My oldest TTL.

8th Jun 2023. Long awaited: The Cypress Semiconductor CY8CKIT-059 PSoC 7LP is on the market again, look at Mouser; in stock: 474 (06/08/2023). What do you need that for: FluxEngine.

2nd Jun 2023. I would like to thank Joe Killian. I am now in contact with him by email and he is helping me with this page about the history of IMSAI.

1st Jun 2023. IMSAI 8080: A switch for the fan.

26th May 2023. IMSAI 8080: Ever heard about the IMSAC 8080?

26th May 2023. IMSAI 8080: Securing the fuse.

26th May 2023. IMSAI 8080: PSU variants.

26th May 2023. IMSAI 8080: Replacing the paddles.

21st May 2023. IMSAI 8080: Front Panel with ECO 76-0061 mod.

20th May 2023. My IMSAI 8080 is breathing again, but has not yet woken up from the coma.

19th May 2023. A long-awaited event. Tonight I set it up and tomorrow my biggest project begins. Restoration of an IMSAI 8080 (S/N 5293).

17th May 2023. New: 8K static ram board (8KRA) from Processor Technonolgy (Proc Tech). I only had to replace the damaged addressing switch. It works perfectly. This board is stable and solid like a Mercedes Benz from the 124 series.

15th May 2023. One of the very first S-100 boards, the 1K static memory board for the MITS Altair 8800.

26th Apr 2023. Video: Memory testing of my IMSAI RAM-4A with my North Star Horizon.

23rd Apr 2023. The (possible) problem with the S-100 pins 20 & 70 and the IMSAI front panel.

22nd Apr 2023. The various S-100 bus's.

20th Apr 2023. New floppy disk drive: Siemens FDD211-5 (aka World Storage Technology FDD211-5).

1th Apr 2023. Update: Tandon TM100-2/2A.

15th Apr 2023. The various ICs for the S-100 RAM Boards.

8th Apr 2023. Restoring/repairing four S-100 DRC-16K RAM for my N* Horizon (or IMSAI 8080).

2nd Apr 2023. North Star Horizon Addresses and HEX Ranges.

31st Mar 2023. You must read this book. In particular the chapter 4 - Homebrew.

31st Mar 2023. What a lucky find. Four S-100 RAM DRC 16K on eBay US. And also for a reasonable price. Two boards are fine, two do not work reliably.

24th Mar 2023. North Star History.

22nd Mar 2023. I'm currently updating my layout bit by bit. The older pages will therefore look a little different than usual for some time. Build fast, responsive sites with Bootstrap.

19th Mar 2023. My new North Star HRAM-64 S-100 RAM card.

11th Mar 2023. Update: The BASF 6128-C works perfectly with my N* Horizon but they are too long/deep. They do not fit into the floppy cage.

11th Mar 2023. Update North Star Horizon: Reducing the heat generation.

9th Mar 2023. Update North Star Horizon: Making my own hard-sectored floppy disks. I now use a drill press (no drilling, only soft punching). The sector holes will be excellent!

27th Feb 2023. I replaced three faulty MM2102AN-2L with Russian KR565RU2 (KP565PY2) ICs in one of my IMS 8K boards.

27th Feb 2023. Update North Star Horizon: Making my own hard-sectored floppy disks. Easy, peasy!

26th Feb 2023. My 2nd North Star Horizon: Reviving the PSU and capacitors.

23rd Feb 2023. Note: On the North Star Horizon controller the DRIVE SELECT 4 (DS4) is provided on line 34, not on line 6!

22nd Feb 2023. Update: Reducing the input voltage for my N* Horizon to 92V AC.

22nd Feb 2023. Update: The Lowest Confirmed Kaypro II Serial Numbers: picture by David Grimshaw - #002-749.

19th Feb 2023. Update North Star Horizon: Hard-Sectored Disks. With the help of the FLUXDUMP program, the content can now be extracted from the flux files (and displayed).

18th Feb 2023. Update North Star Horizon: File and Image Transfer. Using the CPMTOOLS with North Star images (NSI). Works fine.

17th Feb 2023. Update North Star Horizon: Hard-Sectored Disks.

17th Feb 2023. So that it is not forgotten. You want to read and write hard-sectored floppy disks? Here you are: The FLUXCOPY project (2021) by PAW from Vienna.

13th Feb 2023. North Star Horizon: File and Image Transfer!

9th Feb 2023. NEWSFLASH: My North Star Horizon is alive!

8th Feb 2023. Update: 4116 & 4164 DRAM Tester by Stephen Vickers. Today I have tested 32x 4116 DRAMs for a S-100 RAM card for my North Star Horizon. All DRAMs are fine.

5th Feb 2023. North Star Horizon: Testing the PSU with mainboard (without S-100 cards and ICs). Everything seems to be OK.

4th Feb 2023. North Star Horizon: Reviving PSU and capacitors.

3rd Feb 2023. North Star Horizon: First tests.

2nd Feb 2023. My North Star Horizon was delivered by DHL Express.

23th Jan 2023. New series: North Star Computers.

27th Jan 2023. NEW PROJECT: For me, the year 2023 will be all about the Polar Star. It is also called the North Star. My Horizon is currently still on its way from the USA to Germany. I will report ...

26th Jan 2023. The boom in the solar industry (maybe) has solved the frequency problem with the full-high 8" drives. With the help of a solar inverter, you can generate alternating current at 50 or 60 Hz (pure sine wave) from direct current: DC to AC converter, 24V to 110-120V/60Hz.

23rd Jan 2023. Minor update: Reading hard-sectored disks with KryoFlux.

23rd Jan 2023. Minor update: Greaseweazle.

20th Jan 2023. If you visit my update page regularly, you will have seen that after almost one "Kaypro year" I have returned to my other favorite topic "floppy disk drives". I had to change the subject for a while.

20th Jan 2023. FLUX: My new FLUX floppy drive station.

19th Jan 2023. FLUXCOPY/FLUXTEEN: Reading and writing a hard-sectored floppy disk with 16 sectors.

18th Jan 2023. Minor update: The 8" YD-180 floppy disk drive.

17th Jan 2023. Update: The 8" Shugart 800/801 floppy disk drive and the different TTL and LSI versions.

15th Jan 2023. Minor update: Some pages about using 8" floppy disk drives on MS/PC-DOS compatible PCs.

15th Jan 2023. Update: My Shugart 860 8" floppy disk drive.

15th Jan 2023. My NOS Shugart 800/801 8" floppy disk drive. Requires 115V but with 50Hz; for use in Europe. This drive does not require -5V because it has a (newer) LSI PCB. I bought this on ebay US. But in the USA this drive is not usable, because there are 60Hz in the power grid. For this reason, no one buys it there. What a luck.

14th Jan 2023. My universal power supply: +3.3V, +5V, +12V, +24V, -5V, -12V. In particular for the old 8" floppy disk drives which may need -5V.

13th Jan 2023. Update: 8" power supply. Do I need -5V for the old full-high drives or not?

2nd Jan 2023. New: Kaypro Virtual.

31th Dec 2022. Update: z80pack and cpmtools.

29th Dec 2022. Saving the Kaypro monitor ROM (2K, 4k) to a file.

28th Dec 2022. Building a new CRT copper shield for the Kaypro II.

23nd Dec 2022. Just as a reminder: My PC-34 to Shugart-50 8" floppy adapter or how do I connect an 8" floppy disk drive (50 pin) with a DOS floppy controller (34 pin).

23rd Dec 2022. Update: If you want to format an 8" floppy disk under DOS, then use FDFORMAT.

22nd Dec 2022. Finally I found a picture of the (early) 81-212 interface board of the Kaypro 10. The later 81-212A is well known.

17th Dec 2022. Replacing the Kaypro 10 hard disk with a MFM emulator (by David Gesswein).

13th Dec 2022. Update: Installation manual for the Intel Above Board Plus and Plus I/O. The scan was kindly provided by Burrito78, thank you.

13th Dec 2022. A DRIVE SELECT (DS) switch for the Kaypro II/2. Very simple.

3rd Dec 2022. If you need a good and simple HEXDUMP program for your Windows computer, try Norman Dunbar's program. Just compile it, e.g. with GCC, and you're done.

If you want to compare two HEXDUMP on a Windows computer, try MELD by Kai Willadsen.

22nd Nov 2022. Today I received an email from a Kaypro collector from California. It included pictures of his Robie with the '85 design. Wonderful! He wants to send me more and better pictures. I am curious.

17th Nov 2022. 8 inch floppy disk drive: Shugart 800/801 voltage/frequency conversion.

15th Nov 2022. I just started my FAQs for the Kaypro.

12th Nov 2022. Today is a craft day! Finally I managed to connect my MEAN WELL RPT-75B (+12V, -12V, +5V) power supply to the original Kaypro harness. This power supply is very small and has an output of 72 watts. My intention was to connect the original Kaypro harness to a modern power supply without any further adjustments. The following test with a hard disk worked perfectly. All voltages are correct.

11th Nov 2022. You need a new keyboard socket for your Kaypro? Try Mouser: TM1R-616P44-35S-150M. It fits!

8th Nov 2022. What a brilliant speed mod (with switch). for the Kaypro II.

4th Nov 2022. Today I took a closer look at my Kaypro II (#010-408) because the monitor only displayed a vertical bright line in the center of the screen at irregular intervals. After about 40 minutes, I found the error. Completely trivial. The circuit board of the video pcb had a broken solder joint. I soldered this and a few other strange joints and the monitor works fine again. If all bugs were that easy to find!

4th Nov 2022. As the saying goes: "The expert is amazed and the layman is surprised." Simply ingenious. Made by: PROTIQ GmbH, Germany. The material is: PA 1101 - polyamide 11. The part fits perfectly. Go to Thingiverse. With a little luck you will find a provider who processes PA 1102 black – Polyamid 11. Otherwise paint it black as I did.

4th Nov 2022. Frank Rahman pointed out to me that there is another P/N for the Kaypro 4 ('83) -> 81-006.

2nd Nov 2022. Rebuilding the 81-149C ROM for the Kaypro II with M80 and L80.

30th Oct 2022. I found a new "picture" of a 81-302-B ROM for the Kaypro 10('83). Sorry, but I have no ROM file yet.

29th Oct 2022. I completely deleted my Twitter account @retrocmp. The bird no longer chirps.

29th Oct 2022. Do you need a new support-foot and cord-retainer for your Kaypro? Vince from France took the trouble and provided the 3D print file on Thingiverse.

29th Oct 2022. New pictures: Kaypro 10 ('83) mainboards 81-180 B and C.

23rd Oct 2022. CP/M 2.2E by Plu*Perfect Systems.

21st Oct 2022. The RoadRunner ROM for the Kaypro II or 4 ('83) by Howard Saltzman (Highland Microkit).

19th Oct 2022. New downloads: Keyboard Controller ROMs from Kaypro II and 10 ('83).

16th Oct 2022. New picture: External monitor adaptor by Advent for the Kaypro 2/II/4.

7th Oct. 2022. Just a reminder: Douglas Miller has created a replica of the Kaypro 10 ('83) interface board with KiCad.

7th Oct. 2022. Just a reminder: My Gerber files for the Plus-4 decoder for the Kaypro II & Kaypro 4.

3rd Oct. 2022. Update: My new Kaypro front page is finished.

1st Oct. 2022. Update: The Lowest Confirmed Kaypro II Serial Numbers: Frank Rahman - #002-775.

26th Sep. 2022. Please contact me if you have information, pictures and the like about Kaypro you want to share with the Kaypro community. For example, today I received an email from Stephen Stone (Kaypro Users Group of Santa Barbara, CA). I was pleased! Here is his speech at VCF West 1.0: Life and times of Kaypro computers, 1997. Listen to it, you get a very good overview!

22nd Sep. 2022. What does the skateboard champion Henry Hester has to do with Kaypro? Read here.

21st Sep. 2022. Update: The Kay family and the Company.

19th Sep 2022. Today I had a third video call with David Kay.

At this point, I would like to express my heartfelt thanks to David kay once again. The conversations are literally a cornucopia of information from a bygone era.

18th Sep 2022. The Son of the (Ferguson) BigBoard I.

15th Sep 2022. Today I had a second video call with David Kay. The conversation was very pleasant and very informative. Did you know the story about the Ferguson Board and the BIOS? Then let yourself be surprised!

9th Sep 2022. If you want to delve a little deeper into Kaypro's history, read chapters 2 and 3 of the book The Silicon Jungle by David Rothman.

6th Sep 2022. Today I did a forty minute video call with David Kay. The conversation was very pleasant and informative. The results I will gradually add to my Kaypro web pages.

2nd Sep 2022. Update: News about the 81-110 mainboard.

2nd Sep 2022. Update: Kaypro Information and Downloads. Kaypro II Dealer Reference Guide, 1982.

8th Aug. 2022. Update: Your Kaypro 10 ('83) does not work with the KayPLUS or TurboROM? Then you probably have the wrong interface board.

5th Aug. 2022. Kaypro newsflash: You really need to read the book "The Silicon Jungle" by David H. Rothman, at least chapters 2 and 3. Search: The Project Gutenberg EBook of The Silicon Jungle, by David H. Rothman. It is available as ebook or simle text file. It is a cornucopia of information! Can be read wonderfully on the iPhone or iMac.

5th Aug. 2022. Update: Kaypro revisions and versions. Changing from single to double density.

5th Aug. 2022. Update: The Kay Family: David Kay, the visionary.

31st Jul 2022. Update: Kaypro II with vertical drives. The lowest confirmed serial numbers.

31st Jul 2022. Update: Micro Cornucopia. Added the ROM for the 8" adapter board. Very rare!

26th Jul 2022. Upgrading the RTC and the hard disk interface parts on the '84 Kaypro series.

25th Jul 2022. Update: Micro Cornucopia. Added ROM pictures and PRO-8 manuals.

24th Jul 2022. Update: Kaypro Information and Downloads. Added Micro Cornucopia PRO-884 MAX ROM, PRO-8 manuals.

23rd Jul 2022. Virtual machines: Using Oracle's Virtual Box with the same virtual DOS machine (VDM) on Windows 10 or macOS. You will also find here the Virtual Kaypro Computer by Douglas Miller and CPMSIM, ALTAIRSIM, IMSAISIM and CROMEMCOSIM by Udo Munk.

23rd Jul 2022. Update: Kaypro Infomation and Downloads?

17th Jul 2022. Will CP/M talk to DOS.

2nd Jul 2022. Using Kermit on the Kaypro (II, 4, 10 and Robie).

29th Jun 2022. Did you know that there were three different revisions of the Kaypro 2X? And do you know the story about the circus tent?

28rd Jun 2022. The last days I spent a lot of time with the revision of the versions of the mainboards and PCBs.

24th Jun 2022. Delivered today and it works perfectly: My Kaypro Robie; not with original Drivetec drives. But that does not matter.

23rd Jun 2022. Kaypro hardware: SWP CO-POWER-88 board.

23rd Jun 2022. Todays view: Del Mar Airport / San Dieguito Lagoon.

18th Jun 2022. Kaypro's financial roller coaster.

17th Jun 2022. Kaypro Robie - original and redesign.

10th Jun 2022. Kaypro information: Kaypro II schematic from Mirco Cornucopia; scan from the original, 33 x 23 inch, 300 dpi, TIFF, 17 MByte.

6th Jun 2022. UNIVERSAL MAINBOARD sections and IC list.

5th Jun 2022. KayNet - Local Area Network for the Kaypro.

29th May 2022. Non-Linear Systems (NLS) headquarters, the old Stratfort Inn Garage and Del Mar Airport and other minor revisions.

27th May 2022. Since about a week I am also active on Wikipedia Germany: Kaypro, Non-Linear Systems (NLS) and Andrew F. Kay. It's not as complicated as I thought.

22nd May 2022. There are always discussions in the forums about which Kaypros have a UNIVERSAL MAINBOARD. Just look at the Kaypro documentation, it is written there in black and white.

21st May 2022. Today I finally managed to assemble my modified Kaypro II with 5 MHz, four floppy drives, the Micro C PRO-8+ ROM and a rebuilt Plus-4 decoder. Everything works well.

17th May 2022. Is it a real Kaypro II or a Kaypro 4 in drag?

13th May 2022. Kaypro II 81-232x BIOS messages.

13th May 2022. Who has the lowest serial number for the Kaycomp II or Kaypro II?

003-309 - Jim Forbes - Sierra Vista, Arizona, USA

12th May 2022. Update: Kaypro design views. Kaypro II/2 back side.

10th May 2022. Update: Kaypro versions.

9th May 2022. The tiny difference in the Kaypro II 81-149x BIOS messages.

9th May 2022. ROM download for the Kaypro II, 81-149; not version A, B or C! The first Kaypro II ROM. From my Kaypro II with serial no. #4,037; with the original ROM sticker. The EPROM is a "National MM2716".

6th May 2022. There are always discussions in the forums about which Kaypros have a UNIVERSAL MAINBOARD. Just look at the Kaypro documentation, it is written there in black and white.

30th Apr 2022. Now I also know the difference between the PRO-8 and PRO8+ ROM from Micro Cornucopia!

29th Apr 2022. You can download the Gerber files for my Plus-4 Decoder Board (v1.1).

27th Apr 2022. Update: My Plus-4 Decoder Board (v1.0) is ready and running.

24th Apr 2022. Changing a FD-55GFR (1.2M) into a FD-55F (720K) ... or, how do I get my drive to spin at 300 RPM instead of 360?

24th Apr 2022. Update: TEAC FD-54B.

22nd Apr 2022. Update: Micro-C Plus-4 Decoder Board.

22nd Apr 2022. Various revisions and additions: Kaypro hardware. Comparing the Kaypro 1 and the Kaypro 10 ('84) universal mainboard.

21st Apr 2022. Various revisions and additions: Kaypro hardware - Mainboard Kaypro 4 ('83).

18th Apr 2022. Today is truly a beautiful day! Actually I wanted to do something completely different, but then I took a breadboard and assembled my own Micro-C Plus-4 Decoder Board. And what can I say, not one mistake, it works flawless. It is only a prototype and looks a little strange, but KiCad is already waiting!

17th Apr 2022. Update: Repairing my Kaypro II (#4,037).

17th Apr 2022. I reassembled my (vertical) Kaypro II (#4,037) today with the original ROM (81-149) and CHARACTER ROM (81-146).

As boot disk I used the floppy disk I got with my Kaypro II (#10,408). It still works fine and I can now confirm that there are indeed two different Kaypro II CP/M 2.2 versions, the one with the two-line CP/M sign-on message and the one with the one-line CP/M sign-on message. I have read about this two-line version in the Micro Cornucopia, issue 42, Juli-August 1988, page 84. This is a very early Kaypro II CP/M 2.2 version. The later ones are one-line.

15th Apr 2022. What a wonderful day it is today. The last weeks I always had problems, that with my Kaypro II (#4037) the mainboard is ok, but still the screen showed nothing! Ten days ago my new Kaypro II (#10408) arrived from the USA, which works perfectly. So I discharged both display tubes correctly, then replaced the Elston video mainboard and lo and behold the #4037 works fine. Great! Out of curiosity, I then installed the supposedly defective video mainboard from the #4037 into the #10408 and I can't believe it, it works too. The picture is a little distorted, but that's what the regulators are for. As the German saying goes: "The expert is amazed and the layman is surprised." I am a layman. ¯\_(ツ)_/¯

So now I have three Kaypro II (#4,037, #10,408 and #34,644). The #4,037 is a Kaypro II with vertical drives and the front mounted brightness control. The #10,408 has two horizontal drives and the #34,644 is modded; Micro Cornucopia PRO8 ROM, 5 MHz and a 360K and 720K drive.

Aside. I still find the Kaypro II the best because you can tinker the most here. If you want to and are able to. I will definitely do the so called DRIVE FIX MOD on the #4,037 and #10,408. All you need to do here is wire the 74LS390 at U87 a bit; no big deal.

14th Apr 2022. Various revisions and additions in Kaypro versions.

13th Apr 2022 / macOS: How do I delete a file in the Finder under macOS without using the mouse? Since I grew up on the computer without a mouse and prefer to use only the keyboard, I hate it especially when I have to switch from keyboard to mouse during an operation. Terrible! This is also the case when deleting files. With the keyboard and CMD+BACKSPACE I can delete but always comes the stupid query whether I really want to delete. Yes, of course I want to! How do I get the focus to the DELETE button without using the mouse? I have tested dozens of keyboard combinations and with CMD+L (German keyboard) it finally worked. With the English keyboard I would guess CMD+D. It should always be the first letter of the button name!

8th Apr 2022. Update: CPMTOOLS and the Kaypro II/4.

7th Apr 2022. Various revisions and additions: Kaypro versions and Kaypro hardware.

4th Apr 2022. My Kaypro Timeline.

4th Apr 2022. Today I received another Kaypro II from the USA. It was not packed properly, but still survived the journey well and works. It has the serial number #10,408, the mainboard 81-110B1 and has a fixed power cord. I am happy :-)

4th Apr 2022. Update: The Company - From NLS to Kaypro.

2nd Apr 2022. Stories and rumors about Kaypro.

2nd Apr 2022. General Topics around the Kaypro - Part 16. Kaypro floppy disk formats, ...

2nd Apr 2022. Update: TOP 3 Usage Statistics

2nd Apr 2022. I have been dealing with the CP/M Kaypro's for a long time and in detail but nevertheless I still find a mistake from time to time. Annoying! Update and revised - Kaypro Hardware!

1st Apr 2022. Your Kaypro II does not work? Be sure to check the data separator at U88!

31th Mar 2022. The riddle about the Kaypro 4E seems to be solved as well!

31th Mar 2022. Have you ever heard about a Kaypro 11?

31th Mar 2022. Today I noticed by chance that my introductory page to the Kaypro versions was included as an external link in WIKIPEDIA (EN) - all Kaypro models detailed - on March 8, 2022. Many thanks to [Polluks]! Here you will also find previously "forgotten or unknown" Kaypro's like the Kaypro 5.

31th Mar 2022. Douglas Miller has created a replica of the Kaypro 10 ('83) interface board with KiCad.

30th Mar 2022. Have you ever seen a black Kaypro 4 keyboard?

28th Mar 2022. Day 8: Tears of Joy. My Kaypro II (#4037) is working/booting again. The floppy disk controller (WD1791) and the data separator (FDC9216) were defective!

25th Mar 2022. In addition to the Kaypro II motherboard versions 81-110-A and -B1, there is also a B2 version.

25th Mar 2022. Day 7: Changing Capacitors.

25th Mar 2022. I have added another chapter to my series about the CP/M Kaypro's: COLLECTIONS. Until now it is only just one collection, but it is a great one. The collector is Chris Singleton from Duncan in British Columbia, Canada. The jewel of his collection is a Kaypro 4X with two (working) 2.6 MByte Drivetec drives. This is the ONLY Kaypro 4X I have seen on the internet so far.

22nd Mar 2022. Day 5: A small success! After 66 good IC's I found a defective one (U65, 74LS243). I stay on it.

21th Mar 2022. Update: Polar D320 Digital tester. Testing LOGIC TTL IC's.

19th Mar 2022. My early Kaypro II - Function and Problem Analysis. Unfortunately, my Kaypro II works only limited, now then. Let's see where the troubles lie.

18th Mar 2022. Arrived from the USA today, after a good 14 days on the "road". A very early Kaypro II (#4037) with vertical drives and an 81-110-A motherboard, 81-149 ROM, 81-146 CHARACTER ROM and an 1791 floppy disk controller.

This is really an old Kaypro II. Probably in original condition; no mods; very good! And lots of dust from the last 40 years!

Brief report: The mainboard seems to be ok but the power supply seems to be NOT quite ok. Instead of +12V only +10,6V arrive at the mainboard. I installed the mainboard in my second Kaypro II and the BIOS message appears. Booting does not work yet because I probably do not have the correct CP/M version and/or the false floppy drive. But I am in good spirits after being devastated at first. The important thing is the mainboard and that seems to be ok.

11:15 p.m., closing time for today, or else something will break.

17th Mar 2022. Kaypro 10 - Interface Board.

10th Mar 2022. Kaypro II - Mainboard 81-110-A & 81-110-B1.

6th Mar 2022. Updated: TOP 3 Usage Statistics.

2nd Mar 2022. Revised: Software / Generics / SuperCopy.

2nd Mar 2022. My latest acquisition: a (very first) Kaypro II (serial #4037) with vertical disk drives and fixed power cable. In transit from California, USA to Germany; will probably take at least four weeks. This will be an "81-110-A" mainboard!

24th Feb 2022. Kaypro II - Turbo Board.

20th Feb 2022. Kaypro II - A solderless CAS/MUX modification for U66.

20th Feb 2022. Kaypro - Part 13: 8 inch drives on a Kaypro. Discovered today! There was also an adapter board from Micro Cornucopia for using 8 inch drives.

15th Feb 2022. Kaypro - Part 13: Micro Cornucopia.

12th Feb 2022. Kaypro II - Using Four Floppy Disk Drives.

11th Feb 2022. Installing a "MHz" switch for my Kaypro II (2,5 or 5 MHz).

10th Feb 2022. The Kaypro II drive fix mod.

9th Feb 2022. Motherboard mod for the Kaypro II or 4: Modifying a Kaypro with 2.5 MHz to 5 MHz.

6th Feb 2022. Kaypro Corporation: Lawsuits and conflicts.

5th Feb 2022. My modded Kaypro II ('83) to 2,5 MHz to 4 MHz. Actually quite simple.

The "very first" Kaypro 10 with a new picture/brochure.

31th Jan 2022. Have you ever heard of the Kaypro 4E? I have not yet either.

30rd Jan 2022. Update: Micro Solutions UniForm CP/M and UniForm-PC.

28rd Jan 2022. Update: Kaypro Part 2: Hardware.

25rd Jan 2022. "The Computer Journal" (TCJ) is a real treasure trove for Kaypro II owners! To be found at "archive.org".

25rd Jan 2022. Motherboard mod for the Kaypro II or 4: Modifying a Kaypro with 2.5 MHz to 4 MHz.

23rd Jan 2022. Motherboard mod for the Kaypro II: Turning a Kaypro II into a Kaypro 4.

23rd Jan 2022. Update: You're wondering why Kaypro changed the name of the Kaypro II to Kaypro 2 ...

23rd Jan 2022. Update: PSU - Astec AA 12350 (65W) for the Kaypro II (from '83).

21th Jan 2022. Update: Problems with the Kaypro 10 in the early days; hard drive, interface board, BIOS.

20th Jan 2022. Part 12: Kaypro design views.

I actually discovered a completely "new" Kaypro 10 model today. This is the predecessor of the all-knowing Kaypro 10. This predecessor has a 10 MByte hard disk and the floppy drive arranged horizontally, just like the Kaypro II. This pre-Kaypro 10 has a half-high floppy drive with a capacity 200 KByte!

16th Jan 2022. The download link for the TEAC brochures has been faulty for months now and no one ever gives any feedback, too bad. Until today. Many thanks to Steven H.!

13th Jan 2022. Update: The mystery of the unknown Kaypro 5 is solved!

12th Jan 2022. Update: I have now updated the Kaypro versions and revisions table to the point that I have given it version 1.00.

10th Jan 2022. Update: You have ever wondered where the odd numbers on the mainboards come from? Kaypro Versions.

10th Jan 2022. Update: The Kaypro 5. I found another tiny hint in a newsgroup for a 5" winchester option regarding the Kaypro II (in July 1982). As a reminder, the Kaypro 10 was not announced until November 1982.

9th Jan 2022. Update: Kaypro: I have revised the overview of versions and revisions and documented nearly every (important) record with a reference.

7th Jan 2022. Update: New information about the Kaypro Robie and the Drivetec 320 floppy drive.

5th Jan 2022. Update: The Kaypro 5.

4th Jan 2022. The Babylonian name confusion at Kaypro. Another name appears for the Kaycomp II, the Osborne look-alike model: Kay Pro II.

3rd Jan 2022. Update: Kaypro: Floppy Disk drives / Drivetec 320

1st Jan 2022. After some research, I think I have now identified and described the "four" different Kaypro II variants (from 1982/83).

1st Jan 2022. Best of 2021: TOP 3 Usage Statistics

31st Dez 2021. The riddle about the first Kaycomp II is solved!

29th Dez 2021. At this point I would like to mention that there is no Kaypro IV. There is only the "Kaypro 4" from 1983 and the "Kaypro 4/84" from 1984. The name or label "Kaypro IV" is an invention in the "Internet".

If you think that my statement is wrong, then I would like to ask you to send me (official) documents or sources which show that the name or label Kaypro IV actually existed.

29th Dez 2021. Update: Kaypro: I have revised the overview of versions and revisions, added prices and info about models 2X, 4X, 12X, New Kaypro 2 and Robie.

23rd Dez 2021. Part 11: The Kay Family & The Company

23rd Dez 2021. Update: Kaypro: I have revised the overview of versions and revisions and added two further summaries on this basis.

22nd Dez 2021. Update: Kaypro: Adjusting the Video Board.

20th Dez 2021. Update: Hard disks which were used in the original Kaypro 10.

20th Dez 2021. Update: The unknown Kaypro: The Kaypro V

19th Dez 2021. Part 1: Adding Micro Cornucopia - The Kaypro Column

18th Dez 2021. Update: Replacing the ST-412 with a ST-277R in my Kaypro 10 with Advent TurboROM.

16th Dez 2021. IMSAI 8080 Simulator (z80pack) from Udo Munk (on macOS)

16th Dez 2021. Altair 8800 Simulator (z80pack) from Udo Munk (on macOS)

15th Dez 2021. CP/M Z80 Emulator (z80pack) from Udo Munk (on macOS)

14th Dez 2021. File (De-)Compression: Zipping, Crunching, Squeezing

12th Dez 2021. Part 10: Multicopy Program for Kaypro Computers (Plu*Perfect)

10th Dez 2021. Update: Kaypro ROM: Advent TurboROM from Plu*Perfect / Adding „text“ information (files) from third parties

10th Dez 2021. Update: Kaypro Hardware

9th Dez 2021. Update: Formatting a Kaypro 10 hard disk drive

9th Dez 2021. Part 9: Kaypro ROM: Advent TurboROM from Plu*Perfect / Adding instructions for installing and using a 2nd hard disk drive.

9th Dez 2021. Update: Formatting a Kaypro 10 hard disk drive

9th Dez 2021. Part 9: Kaypro ROM: Advent TurboROM from Plu*Perfect

8th Dez 2021. Part 8: Kaypro ROM: KayPLUS from MICROCode

6th Dez 2021. Update: My series about the Kaypro

6th Dez 2021. Part 7: Kaypro Terminal Emulation

5th Dez 2021. Update: Exchanging the hard disk controller (WD1002-HDO) of the Kaypro 10.

4th Dez 2021. Update: IBM Fixed Disk and Diskette Drive Adapter with PN 68X3814 (2nd gen.)

4th Dez 2021. Update: The Hercules InColor Card (GB222)

31st Okt 2021. Update: The Hercules Product Line - Hercules Graphics Card (GB102Z) and Hercules Color Card.

24th Okt 2021. Update: IBM AT 5170, I have disassembled the complete PSU.

24th Okt 2021. Update: Gotek & FlashFloppy (hardware mods).

20th Okt 2021. A lucky find! I bought a used but not complete IBM AT 5170 on ebay a few days ago. Yesterday it was delivered.

The hard drive is missing, but that was known, the controller WD 1003-WA2 is included (not tested yet). But the most important thing, the motherboard works flawlessly. Otherwise, the YD-DATA YD-380 (1.2MB) and Toshiba ND-356 (1.44MB) are also included (both not tested yet), but they look good except for the stained bezel.

The power supply basically works as well. It only smells a bit. This could be due to age and dirt or scorched but still functional components inside. The power supply I have to look separately and also open it!

When I consider what all the individual parts would cost on eBay, the purchase was a bargain!

17th Okt 2021. Update: Jumper settings for the Panasonic JU-475-2 and JU-475-5.

16th Okt 2021. Two new 5.25" (dual speed, 1.2MB/360KB) floppy disk drives: Panasonic JU-475-2 EAF, Panasonic JU-475-5 AKO; both with beige bezel.

20th Sep 2021. Update: IBM 51xx PC Family Computers / 5170 - Installing a SCSI hard disk drive the AHA-1552B floppy controller.

20th Sep 2021. Update: DEBUG - Low level formatting a SCSI Hard Disk with the Adaptec AHA-1542B.

19th Sep 2021. Memory expansion card: AST RAMpage AT

19th Sep 2021. Update: Memory expansion card: AST Rampage 286

18th Sep 2021. Update: More by chance, I tested my memory expansion adapter AST RAMpage AT (version 202079-301-A) in my IBM 5170 (8MHz). Actually this "6 MHz" card should not work in the "8 MHz" mainboard but it does. I tested with Checkit (RAM, EXT, EXP); so far there have been no problems.

16th Sep 2021. Update: IBM 51xx PC Family Computers / 5170 - Supersoft Landmark Diagnostic Test / AMI 286-BIOS for G2/102.

12th Sep 2021. IBM 51xx PC Family Computers / 5170

12th Sep 2021. Update: DEBUG - Low Level Format a MFM Hard Disk

11th Sep 2021. Today my IBM AT 5170 Type 3 motherboard arrived. The first tests were successful, it works flawlessly so far. At the beginning it was unclear to me which BIOS is installed; there was no original label stuck on. How pleasing, it was the "286-BIOS (c)1989 American Megatrends Inc", very good. So I had the advantage that I didn't have to work awkwardly with GSETUP. Also the low-level formatting of the harddisk was a piece of cake, because a DIAGNOSTIC routine is implemented in the BIOS; with AUTO-INTERLEAVE and BAD SECTOR ANALYSIS.

For the hard disk I use a Seagate ST-225 with the IBM Fixed Disk and Diskette Drive Adapter (2nd generation). As floppy disk drive I use the JU-475-2EAF. This is a dual speed drive, so although the BIOS is configured to 1.2MB, it can also read/write 360KB floppy.

6th Sep 2021. Update: PC-34 to Shugart-50 8 inch floppy disk adapter. Corrected BOM list.

5th Sep 2021. Update: Floppy Disk / Diskettes. Delivery programme and 5.25" hard-sectored disks

1st Sep 2021. They are actually still available for purchase! I have been looking for a long time. 5.25" hard-sectored floppy disks with 10 sector holes.

1st Sep 2021. Update: TOP 3 Usage Statistics - August 2021. TOP 1 is greaseweazle.htm with 257 hits.

30th Aug 2021. Shugart SA850/851

29th Aug 2021. The Mitsubishi M2896-63 in combination with the FLUXTEEN / FLUXCOPY is basically able to read and write hard sectored (8 inch, 32 sectors) floppy disks!

28th Aug 2021. FLUXTEEN / FLUXCOPY: Reading a hard-sectored 8 inch floppy disk with the Shugart SA850/851.

27th Aug 2021. Update: Greaseweazle

27th Aug 2021. Update FLUXTEEN / FLUXCOPY: Project for Hardware and Software for Copying Hard-Sectored Floppy Disks.

26th Aug 2021. FLUXTEEN / FLUXCOPY: Project for Hardware and Software for Copying Hard-Sectored Floppy Disks.

14th Aug 2021. Update: Using the 16 bit Etherlink III / 3Com / 3C509B in an 8 bit XT-Bus computer like the IBM PC (5150) or XT (5160).

12th Aug 2021. New: Source Code

12th Aug 2021. Update: Links

7th Aug 2021. Completely revised: I have a new/another PC-elevATor 286 card for my IBM PC XT 5160.

6th Aug 2021. New record: Aliotta Haynes Jeremiah - Slippin away - USA, 1977, L.F.711

5th Aug 2021. New record: ZZ Top - Eliminator - Europe, 1983, 92-3774-1

2nd Aug 2021. As of today, I also use a new search engine: www.startpage.com. The first impression is very good. I have found things that Google has never shown me before. That's what you get for living in your personal internet bubble all the time!

2nd Aug 2021. Update: 8 inch drives and DOS - Some new very interesting external links (boginjr.com). Have a look!

1st Aug 2021. Update: RC2014 Accessing DOS partitions with FAT.

1st Aug 2021. Just a quick note in passing. My absolute favourite IDE hard drive is the Seagate ST320410A. It is quiet (5.400 rpm) and perfectly suited for DOS or the RC2014 with CP/M.

31th Jul 2021. Something completely different today. Since the runtime behaviour of my somewhat older Lenovo ThinkPad E145 (2013) with Windows 8.2 was a disaster, I decided to install Linux Mint on this wonderful little notebook. But, ... it just won't work, to hell with it. WLAN does not work at all, no way!

After hours of trying, installing and pulling my hair out, I found the error. The magic words are: Unified Extensible Firmware Interface (UEFI) and Secure Boot.

Reason: The Broadcom BCM43228 (Linux WLAN driver) is not certified and is not accepted in UEFI secure boot mode. Uninstalling and reinstalling (bcmwl-kernel-source) also did nothing.

Solution: I completely switched off the UEFI and Secure Boot mode in the BIOS, then „complete“ reinstalled Linux Mint and everything works wonderfully. The Broadcom WLAN driver is automatically recognised and installed.

Kernel: 5.4.0-80-generic x86_64 Desktop: Cinnamon 5.0.5
OS: Linux Mint 20.2 Uma base: Ubuntu 20.04
WLAN: Broadcom and subsidiaries BCM43228 802.11a/b/g/n

Why does everything have to be so complicated today? As Dumont said in the film Tron: In the past, the systems were all free and there was a wonderful exchange of data.

27th Jul 2021. RC2014: Accessing DOS partitions with FAT.

27th Jul 2021. Update: Many RC2014 pages.

25th Jul 2021. Update: RC2014 Images.

25th Jul 2021. After more than a year I unpacked the RC2014 and built it up again. Next I want to revise my internet pages about the RC2014 and assemble/solder the VGA Terminal Kit by Marco Maccaferri. It's been lying around here for at least a year. My goal is to install the complete RC2014 in a modern ATX case and then operate it with VGA and keyboard. That shouldn't be too difficult.

24th Jul 2021. Update: Y-E DATA YD-180-1601.

24th Jul 2021. Update: My test systems.

21th Jul 2021. Update: Mitsubishi M2896-63-02M.

21th Jul 2021. Update: Bootsector & BIOS Parameter Block (BPB). NEC APC (8", MS-DOS 2.11) bootsector.

16th Jul 2021. Floppy Disk: Bootsector & BIOS Parameter Block (BPB).

11th Jul 2021. Let us go Virtual: Oracle VM VirtualBox on my Windows 10 computer. Also WinImage and ImDisk.

10th Jul 2021. A last entry on the fly. Today I installed the "Oracle VM VirtualBox" on my Windows 10 computer and created a virtual MS-DOS 6.22 box. Works perfectly. Disk images can be integrated as a "floppy disk drive" without any problems. But the best thing is that in connection with WinImage 10.0 you can open the virtual DOS box directly if you have created it as a VHD image. You can then copy files from Windows 10 directly into the virtual box using drag & drop.

8th Jul 2021. Update: Microsoft Knowledge Base Articles.

7th Jul 2021. Complete revision: I have also added a little floppy maths to the MS-DOS floppy disk formats table. Also: Differentiation between data rate and clock rate.

5th Jul 2021. Update: New pictures of the TEAC FD-55AV.

4th Jul 2021. Update: Kryoflux and Greaseweazle.

2nd Jul 2021. Update: Floppy Disk / Diskettes.

30th Jun 2021. Update: Examine the standard IBM MFM track format.

26th Jun 2021. Update: Floppy Disk Drive / FDC / Steprate. Change the steprate with user input.

26th Jun 2021. Update: 8 inch drives and DOS

26th Jun 2021. Why to Change the Steprate for very old Floppy Disk Drives: Floppy Disk Drive / FDC / Steprate.

24th Jun 2021. Update: Let's do the Twist Again - Floppy Disk Drives / Data Cable.

21th Jun 2021. Update: I found four new TEAC FD-55 drive types on the Internet again today (TEAC FD-55BV-31-U, TEAC FD 55GV-14-U, TEAC FD-55GFR-620-U, TEAC FD-55GFR-7393-U).

21th Jun 2021. Update: How to terminate a floppy disk drive - the termination resistor.

20th Jun 2021. Update: Today I discovered pictures and information of the TEAC FD-50 on the internet.

20th Jun 2021. Update: Today I discovered pictures of the TEAC FD-54 on the internet.

15th Jun 2021. New project: FLUXCOPY: Project for hardware and software for copying hard-sectored floppy disks.

15th Jun 2021. Update: I have found another TEAC FD-55 model on the Internet that I don't know: FD-55GV-33-U.

13th Jun 2021. Update: ISA Floppy Disk and Serial Controller - Sergej Kiselev / I added some screenshots.

12th Jun 2021. Stupidity must be punished ... or ... Those who can read have a clear advantage in life!

Never operate a 110 volt power supply with 220 volts, because it "could" burst! I could slap myself. And it was clearly written on the power supply unit: operate only with 110 volts! This is what happens when you ignore your own warnings! Luckily only the power supply unit is broken, my IBM PC 5150 (16-64KB) survived!

11th Jun 2021. Update: 8 inch drives and DOS

6th Jun 2021. Today is one of those days to test new things. Some time ago I came across Dave Dunfield's site on the internet and became aware of his Micro-C compiler and the "Dunfield Virtual Machine". Just try it out, it's worth it! Dunfield Development Services

I have been using his IMAGEDISK (IMD) programme for years; simply brilliant, it has never let me down!

5th Jun 2021. I will gradually expand the Altair/MITS chapter a little.

28th Mai 2021. Update ASM-LIB on Github. BPB.ASM : Display information from the BIOS Parameter Block of drive A:.

27th Mai 2021. Some information about the boot sector and BIOS parameter block (BPB).

23rd Mai 2021. My PC-34 to Shugart-50 8" adapters are on Github. There you can download the Gerber files.

23rd Mai 2021. A long-awaited goal of mine is to learn assembler. In the past, I programmed mainly in Turbo Pascal and also a little bit in C. But that was almost 30 years ago. Well then, a rolling stone gathers no moss. In 2018 I started with assembler, but then took a very long break. Now I want to start again. I am currently setting up a repository on Github.

17th Mai 2021. Goal achieved: Raspberry Pi Floppy Controller Board

15th Mai 2021. Update: TEAC FD-55 / my „data base“: FD-55BV-36-U, FD-55GFR-184-U, FD-55GFR-197-U

15th Mai 2021. Update: TEAC FD-55A (LSI version)

8th Mai 2021. Raspberry Pi: Floppy Controller Board

28th Apr 2021. Today I became aware that I have completed my collection of the „Big Five“: CompatiCard, OptionBoard, Catweasel MK4, KryoFlux and Greaseweazle.

I have not yet described anything about the Catweasel, but I have had the adapter for a few years. I am currently working on the Greaseweazle.

28th Apr 2021. Update: KryoFlux Floppy Station

28th Apr 2021. Update: IBM XT Model 286 (XT/286) / 5162 (512+128KB)

25th Apr 2021. Today I created a template for new floppy disk sleeves: PDF, Affinity Designer or JPG. You can change the template according to your wishes. Scale to 100% when printing; the cutting pattern should be self-explanatory.

23rd Apr 2021. Update: Jumper settings - NEC FD1165

19th Apr 2021. Some information about the 1541-II Commodore disk drive: R/W head, gap and core geometry, half-tracks, double-stepping, ...

11th Apr 2021. Actually, I wanted to continue working on my C64C project today. Somehow, however, I got a bit off topic about D64/G64 images, VICE and „KryoFlux“, and I quickly put together my new KryoFlux test station. Tinkering is simply fun.

I installed two TEACs (FD-55BV-06-U / 360KB and FD-55GV-20-U / 1.2M) in a sturdy drive cabinet on the left. On the bottom right is the KryoFlux and above that the TEAC ALPS 3.5" (1.44MB / 720KB). Nothing moves, everything is really stable.

10th Apr 2021. New project: Commodore C64C

6th Apr 2021. Update: PC-34 to Shugart-50 8" adapter.

5th Apr 2021. So, everything should be up to date at the moment. Let's see what the next project will be.

With my RC2014 I would still have to solder the VGA card and integrate it into the overall system. And then there is the installation of the complete system in an ITX case. Let's see.

5th Apr 2021. Update: IBM XT Model 286 (XT/286)

5th Apr 2021. Update: Xircom PE3 / Pocket Ethernet Adapter III

3rd Apr 2021. Update: Networking and Data Transfer & Etherlink III / 3Com / 3C509B

2nd Apr 2021. Update: IBM XT Model 286 (XT/286)

1st Apr 2021. Update: How do I install an 8 inch (8") floppy disk drive in a IBM DOS or compatible PC?

31st Mar 2021. Update: IBM XT Model 286 (XT/286) / Back to the Roots

27th Mar 2021. And there you go: PC-34 to Shugart-50 8" adapter. The new PCBs arrived today. Ordered on 11/03/2021, they were in production on 12/03/2021, shipped on 16/03/2021 and delivered by DHL on 26/03/2021.

Cost and shipping for 5 PCBs:$2,50 USD, $9,39 USD. Import duties have not been incurred. That would be $2.38/PCB.

21th Mar 2021. Update: Using KERMIT on my Altair-Duino (Altair 8800).

13th Mar 2021. It is done! The Altair-Duino Pro is now fully assembled and works perfectly!

The Altair 8800, even if only as a simulator, is a whole new world for me. Mounting and unmounting floppy disk drives with the switches simply ingenious. Of course I know the process as such from UNIX, but with the switches ...

Result: The kit was not cheap, but the purchase was worth it!

12th Mar 2021. My new soldering project: Altair-Duino Pro. The project's progress on Twitter. Today I soldered all the switches and LEDs. A first function test: everything is OK.

10th Mar 2021. UniForm-PC and UniForm. Some new brochures.

8th Mar 2021. And there you go: PC-34 to Shugart-50 8" adapter. It's working.

7th Mar 2021. My new soldering project: Altair-Duino Pro. The project's progress on Twitter

4th Mar 2021. Picaxe: Not RETRO, but it's still fun. The Nano-Axe-Board from Heise Verlag (www.heise.de/make/).

23rd Feb 2021. My latest project: KiCad! To be continued. Just commissioned at JLCPCB. I have never designed circuit boards myself.

23rd Feb 2021. Floppy Disk drives: Jumper Settings.

21st Feb 2021. Update: Recording problems / Reading, writing and formatting 360K disks in 1.2M drives.

19th Feb 2021. Update: How do I Connect a 8 inch (8") FDD to a DOS PC?

15th Feb 2021. Finished: RX-180 (2x Shugart SA 400L) with my IBM PC 5150.

13th Feb 2021. How to DOS format an 8" floppy (1.2 MB, 77 tracks)? FDFORMAT

11th Feb 2021. Are You READY (or DISK CHANGE)? Floppy Disk Drives: Bus Interfaces

6th Feb 2021. My new 8" floppy disk drive: Y-E DATA YD-180-1601

5th Feb 2021. Using a Gotek with FlashFloppy.

30th Jan 2021. Using CompactFlash (CF) cards in a DOS retro PC

30th Jan 2021. As of today, I also own a GOTEK drive with FlashFloppy. The application is actually very easy once you have understood the file exchange with the images. Almost 12,000 images at 1.44MB fit on my USB stick. That's incredibly practical, but unfortunately a piece of retro culture has disappeared! There's nothing like a TEAC FD-55B with a proper HEADLOAD magnet.

29th Jan 2021. I simply cannot praise it enough, but Michael B. Brutman's mTCP tool is simply ingenious. I have it installed on almost all my DOS retro computers. You want to make a backup of your system? Nothing easier than that. Just start the mTCP FTP server on your local DOS machine and in no time you have all your files backed up to your central FTP server!

27th Jan 2021. So, I'm in the process of reconditioning my five Tandon TM100-2A. Actually, all the drives work well, but since I enjoy soldering, I will now gradually replace all the problematic capacitors. I started today with my model without IBM logo from September 1983 (serial no 3 36 00008638, assy no 171000-001). I replaced all eight (C1, C17, C26, C36, C37, C38, C43) tantalum capacitors (16V/4.7uF) with 25V/4.7uF electrolytic capacitors; 25V instead of 16V is completely unproblematic. You must just NOT use less than 16V. It took me about half an hour to do this.

During this work I noticed that the capacitor C37 is present on the circuit board of this model. In all my other models (assy no 171172-001) C37 is missing!

I think soldering is a great way to relax and not have to think about Corona all the time!

I just saw that I forgot C30. They used a different coloured tantalum here at the time. Tomorrow is another day!

24th Jan 2021. Update: Intel Above Board Plus

22nd Jan 2021. Update: ISA Floppy Disk and Serial Controller / Lo-tech 1MB RAM Board by Kevin R. Williams (texelec) and USE!UMBS software.

22nd Jan 2021. Update: My testsystems and floppy stations.

20th Jan 2021. Update: DEBUG - Low Level Format a MFM Hard Disk

18th Jan 2021. What is the saying? "Never touch a running system!" For this reason, I struggled for a long time whether to replace the 16V tantalum capacitors on my 5150 (16-64K) mainboard. But since I'm doing my current project with this board and often switch the PSU on and off, I replaced all 17 capacitors today. This was no problem with my desoldering gun. Everything is fine. There is nothing more terrible than a tantalum capacitor exploding 50 cm in front of your face!

17th Jan 2021. Update: ISA Floppy Disk and Serial Controller / ROM Address Selection to 0xF2000 & 0xF4000 and yes it works!

16th Jan 2021. Soldering: ISA Floppy Disk and Serial Controller - Sergej Kiselev / A first quick test: Everything worked perfectly, the controller works flawlessly on my IBM PC 5150 (16-64KB).

15th Jan 2021. Abbreviations: It's a bit tedious, but I decided to start a page with abbreviations. Each abbreviation is also followed by a link to further references (usually this is WIKIPEDIA).

13th Jan 2021. TMC IFSP: One Controller, Four Floppy Disk Drives

12th Jan 2021. Today I got two used but very well preserved and perfectly working TEAC FD-55GV-20-U. These are pure 1.2MB drives. The drives were used in the DOS-compatible Process Controllers PCA 2/5/12/15 from Rohde und Schwarz (R&S).

TEAC type G (not GF) drives (96tpi, HD, single speed) were intended as direct replacements for 8 inch drives. According to the brochure, they only have 77 tracks, but they can be formatted with 80 tracks without any problems.

My tip: Use only 48tpi drives for 360K (DD) disks for your retrocomputing, do not use them in 96tpi dual speed drives. If you do not do this, you will have problems sooner or later. Trust me!

10th Jan 2021. What a fiddly job. Today I took out about 140 DIL RAM's from my two memory expansion cards, checked them with the RAM tester and plugged them back in according to the required speeds (150ns or 100ns).

12th Jan 2021. Update: Memory expansion card: AST Rampage 286

11th Jan 2021. Intel Above Board Plus

8th Jan 2021. Shugart 400L

7th Jan 2021. IMPORTANT: If you really want to use old floppy drives, such as the Shugart 400 (~1978) or 400L (~1981), then you cannot do so easily! Why? The Shugart 400 has a track to track steprate of 40 ms, the 400L of 20 ms! Even the TEAC FD-55A or B only have a steprate of 6 ms, which is 3 to 6 times faster.

Even in my IBM PC 5150 with the original IBM floppy controller I kept getting read and write errors (sector could not be read ...). Referring to the "5-1/4" Disk Drive Adapter" manual from IBM, this controller works with a constant steprate of 6 ms. This is too FAST!

I have tested my two Shugart 400L in my IBM XT 5160 with a CompatiCard IV, here I can explicitly specify the steprate. And lo and behold, with a value of 20 ms, both old drives suddenly work perfectly!

I will include this note later in my report on the RX180.

2nd Jan 2021. Floppy Disk Drives, Data Cable / Let's do the Twist Again

1st Jan 2021. Nothing lasts forever. Today, a Tandon TM100-2A simply went out of service! No bang, no smoke, nothing. But since I still have three of these drives in reserve, it wasn't so terrible. Let's see if I can find the fault and repair the drive.

31th Dec 2020. I wish everyone a happy new year and stay healthy!

30th Dec 2020. 8" floppy disk drives / I have added the chapter on electricity grid frequency to the general page on 8 inch drives.

29th Dec 2020. 4116 & 4164 DRAM Tester by Stephen Vickers

27th Dec 2020. RX180 / My new external double floppy disk drive.

26th Dec 2020. My upcoming projects.

26th Dec 2020. Update: IBM XT 5160 (64-256K) / Upgrading an old IBM PC/XT to 640k.

26th Dec 2020. So, the basis for my new long-term project is laid: Intel Inboard 386 Cable for the IBM AT. It will take a long time until I have all the components together.

22th Dec 2020. A quick report: IBM 5162 (XT/286) / I changed the crystal Y1 from 12 MHz to 16 MHz. My 5162 now operates at 8 MHz.

21th Dec 2020. Update: XT-XF-Lite

20th Dec 2020. Update: IBM XT/286 / IBM MOD 5162 BIOS, Supersoft Landmark Diagnostics, XTIDE Universal BIOS (XUB) R602

16th Dec 2020. Changing the BIOS for the IBM XT/286. I use a third party BIOS from AWARD or AMI for the IBM 5162. Works fine!

12th Dec 2020. A quick report: My IBM 5162 (XT/286) mainboard works perfectly. You have to make a setup diskette in advance, because the BIOS is „reset". Either use "Diagnostics for IBM AT and IBM XT Model 286" or the programme „Generic SETUP" (GSETUP.EXE). Both can be found on the Internet. TEAC FD-55BV (360K), TEAC FD-235HF (1.44M), Seagate ST-212 (10M).

8th Dec 2020. Alice Cooper - Trash (1989), simply just good!

7th Dec 2020. I forgot to tell you, besides old computers I also have many LPs and music cassettes. Just arrived today from Great Britain (Made in England). A music cassette from 1977: Jean Michel Jarre - Oxygene. And what can I say. It sounds almost perfect and that after 43 years! My tape decks: Pioneer CT979 and Technics RS-BX707. Analogue music is simply ingenious, isn't it?

4th Dec 2020. I have listed all of my known TEAC FD-55 models in an extensive spreadsheet and noted their similarities. To be continued ...

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

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!

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

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.

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

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

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

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

10th Jul 2020. Memory expansion card: 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

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

30st May 2020. Update Microsolutions backpack CD-ROM

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.

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.

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

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.

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

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.

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

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

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

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

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!

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

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

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.

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"

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 burn/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