Digitus KIM-1 clone

Scandinavian? KIM


Found this photo in a Facebook group, from an Ebay auction. , no more information known. Looks like a standard KIM-1 with 2x 2114 SRAM ICs for the standard 1K RAM.

Recently on Ebay an identical KIM-1 lookalike showed up. The PCB is inspired but clearly newly designed.
Armin Hierstetter bought it and send me the following photos.



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Proton PC-1

The Proton PC-1 is a 6502 based computer in a keyboard case. Produced by the Dutch electronics firm Post Electronics, later known for the Ultiboard software.
Targeted at students an hobbyists.

A full size keyboard, a 6502 at 1 MHz, a VIA 6522 and optional cards for extra ROM (with Basic), video display cassette interface.
Standard a 16 character alphanumeric display is built in above the keyboard.
One of my Protons came in a suitcase with the Proton logo.


I know of 3 Proton PC-1s, which are slightly different. The first two I owned look alike, the third one (owned by Dirk Prins) shows the PA port of the VIA 6522.

Advert on the backpage of the KIM Kenner Club Magazine 29, 1983:

Proton PC-1 photo by Dirk Prins

Downloads:

Proton PC-1 User’s Manual
(Original from Henk Verbeek, converted to black and white and fixed as much as possible by me)
(updated on April 26 2025 for page 19 missing a piece)
Proton PC-1 source as typed in from the manual and/or disassembled by Dirk Prins and the ROM dump
This is not finished, Dirk Prins is working on completing the source.
The source delivers already a binary equal to the ROM dumped by Dirk Prins

Photos by Henk Verbeek of his Proton PC-1

MTU Micro Technology Unlimited pages updated

The MTU pages have been updated.
– New are 8 documents on the MT-130 page, like DISKEX (file exchange with e.g. CP/M), Wordpic, Forth 79, later version of the Full Screen editor.
– The K-1013 Dual density floppy controller has its own page now, with new information
– The MT-130 is emulated on Mame
– MTU K-1000 power unit photos
– the MTU projects by Eduardo Casino

Not yet added are the results of the ongoing discussions on the threads on forum64.de, like multipage K-1008 displays, K-1013 replica builds, CODOS V1 and V2 dissecting.

K-1008, photo by John Lucas

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MTU and Eduardo Casino

Since 2023, after replicating a working KIM-1 Rev D PCB, Eduardo has been replicating and enhancing MTU products.

See his github pages filled with MTU designs and his blog about his work.

An (incomplete, he adds regularly so check his pages) list of projects:

– KIM-1 Rev D replica (with keyboard and 6530 replacement board)
– MTU K-1008 Visable memory video card, with software
– MTU K-1013 Double Density floppy disk card (with CP/M-65 as operating system and ongoing work on CODOS)
– MTU Expansion card
– MTU Motherboard
– MTU RAM-ROM board
– port of CP/M-65 (David Given) to the KIM-1 with SD card, IEC interface and K-1013

Besides his github and blog pages the MTU projects are discussed on the forum64.de forum:
https://www.forum64.de/index.php?thread/142432-k-1013-floppy-disk-controller-replica/
https://www.forum64.de/index.php?thread/124855-instandsetzung-und-nachbau-eines-kim-1/
https://www.forum64.de/index.php?thread/137493-k-1008-visable-memory-card-replica-wip/


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MTU K-1000 power unit

K-1000 Basic KIM-1 power supply, completely enclosed, terminals trip output +5V @ 1.2A, +12V @.01A regulated, +7.5V @.75A, +16V @02A

K-1000 MTU Battery power for the KIM-1


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K-1013 floppy controller

Used in the early KIM-1 MTU bus system and in the MTU-130/140 systems.

  1. 16K RAM
  2. Bootstrap ROM 256 bytes
  3. Double density controller uPD765
  4. DMA circuittry to allow direct data transfer
  5. Up to four 8 inch disk drives
  6. for KIM/MTU bus system

See also the CODOS page for the Operating systems CODOS V1 (KIM-1 etc) and CODOS V2 (MT-130/140/Accupath 1000)
Differences as found by Eduardo Casino between the MTU-130 Double Density Disk Controller and the original K-1013 Floppy disk controller:

  • Add IRQ enable/disable to the control register, implemented with a 74LS175, instead of a 74LS109, to accomodate the extra bit.<.li>
  • MTU-130’s 18 bit addressing support.
  • Different boot rom contents, specific to the MTU-130.

K-1013 from a MT-130, Eric Wright (Accupath 1000)


Backside of K-1013 floppy disk controller with much rework (Dave Plummer)



Floppy controller from a MT-130, David Williams

K-1013 Floppy disk controller Manual
MTU-130 Double Density Disk Controller Manual
MT-130 bootrom (dumped by Eric Wright) and assembler source (Eduardo Casino)

Eduardo Casino has made a replica PCB for the K-1013 Rev. D Floppy Disk Controller replica.
This aims to be a faithful replica of the K-1013 Floppy Disk Controller, an extension board for the KIM-1 designed by MTU in the late 70’s/early 80’s for interfacing with Shugart Associates compatible 8” and 5.25” FDDs.

The PCB is build by several users (see the thread at forum64.de) and found to be working fine. The operating system used is CP/M-65 by David Given.

Replica by Eduardo Casino

Replica by Eduardo Casino


Replica by Eduardo Casino

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MT-130 in MAME

The MAME emulator can do quite a good simulation of the MT-130.

What you will need is:

Now start MAME in GUI mode:

and select MT-130 from the available systems

and start CODOS 2.0

Note that some of the disk images are corrupt. CODOS V2 works!

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AIM 65 keyboard variants

From https://tech.cellfi.sh/

After researching a small lot of Rockwell AIM 65 R6500 Advanced Interactive Microcomputer, there seems to be small variations. Those deserve to be documented. First out, the keyboard variations.

Futaba FK-2054 keyboard found in serial number A43648, A43651, A43653 and A43654.

Stackpole Components 86-90-0030 keyboard found in serial number A31072.

HI-TEK 373-70125 keyboard found in serial number A11220



Futaba FK-2054 key side. Notice the straight line in Q and the plastic keyboard frame.



HI-TEK Part.No. 373-70125 key side. Notice the curly line in Q.



Stackpole Components 86-90-030 key side. Notice the curly line in Q key.

EMUF M50734

Thanks to F.J.Kamerewerd, DL6OE, I have a photo of a EMUF 65XX with a very special CPU, the Mitsubishi M50734.
This CPU is from a family of 65C02 cores with enhancements.
Around this M50734 the EMUF M50734 is published in MC Magazine 11 1911.

See here for the information available.

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EMUF M50734


In the MC Magazine 11 1991 a special EMUF is published.
It is based upon the 6502 compatible Mitsubishi M50734 CPU. This CPU is an enhanced 65c02 in a 64 pin housing.
See the datasheet for the enhancements in instruction set.

The EMUF M50734 is a SBC in the tradition of the 65XX EMUFs.

Probably made by Elektronikladen Mikrocomputer Giesler & Danne GmbH & Co. Detmold

Photo by F.J.Kamerewerd, DL6OE


Photo by F.J.Kamerewerd, DL6OE

The EPROM dump below (thanks F.J.Kamerewerd, DL6OE) shows this Copyright string: MONITOR V.1.1 * (C) 1990 J.S.+ O.M.

EMUF M50734
MC Magazine 11 1991
Mitsubishi M50734 CPU datasheet
MC Magazine 11 1991
EMUF M50734 monitor EPROM dump in Intel hex
EMUF M50734 monitor EPROM dump in binary format