KIM-1 PC utilities

To aid in the handling of KIM-1 program and dataformats I have written some programs for Windows (and Linux after compilation).
KIM Tape WAV to BIN conversion
Convert 8 bit hex formats
Convert KIM Tape To Text
KIM-1 simulator
All programs come with source (Free Pascal Lazarus), compiled for Windows but thanks to Freepascal and Lazarus also to be compiled on Linux.

KIM Paper

Note that the Conver8bitHexFormat program is also capable of converting to and from Papertape format from many more formats.
Originally written for the launch of the MicroKIM, an older version is on the support CD.

When you attach a serial device like the teletype or a modern PC with Hyperterminal you can use the TIM monitor of the KIM-1. One of the functions is loading from and saving to a papertape device on the teletype. Now since this is a way to load and save data as a textfile this is in fact quite useful.
The Micro-KIM triggered me to modernize my conversion utility for MOS Technology papertape format dating from 1983, VAX/VMS and Turbo Pascal. A Windows and a commandline version are available.

KIMPAPER for Windows

A program for Windows to convert between papertape and binary format.

Windows setup KIMPAPER
Sources (Freepascal Lazarus, build also on Linux)


Not too modern, but handy, a commandline utility. Does exactly the same as the Windows program KIMPAPER. Runs fine in a commandline DOS box. Can also be compiled for Linux with Freepascal. In the KIMPAPER DOS archive the program, source and information on the program and papertape format can be found.

KIM-1 Mos Technology BIN papertape format conversion utility, Hans Otten, 2007 v1.1

Syntax is:
KIMPAPER [-[b|p] filename [startaddress]
C:\MICROKIM\kimpaper -h
KIM-1 Mos Technology BIN papertape format conversion utility, Hans Otten, 2007 v1.1
Syntax is: KIMPAPER [-[b|p|h] filename [startaddress] first parameter switches
-h help
-p convert to papertape
-b convert to binary
second parameter (first if no parameters, assumed binary to papertape)
name of file to convert
.BIN for binary, forces conversion to PAPertape
.PAP for papertape, forces conversion to BINary
third parameter (assumed 0000 if not present)
startaddress for BIN to papertape conversion
Files of type .BIN wil force conversion to papertape.PAP
Files of type .PAP wil force conversion to binary .BIN

C:\MICROKIM\kimpaper mastermind.bin 0200
KIM-1 Mos Technology BIN papertape format conversion utility, Hans Otten, 2007 v1.1
C:\MICROKIM>kimpaper mastermind.pap
KIM-1 Mos Technology BIN papertape format conversion utility, Hans Otten, 2007 v1.1
Start address 0200 in file mastermind.BIN

Convert 8 bit hex formats

A general purpose utility to convert common 8 bit hex and binary formats, such as Intel HEX, Motorola S records, MOS Papertape, hex format and binary files.

Windows program, source files (Freepascal Lazarus, also for Linux).

Available formats:

  • BIN binary, raw data, no formatting, no information on start address.
  • HEX formatted as hex numbers raw data, no start address included.
  • IHEX Intel hex 8 bit format, contiguous memory block, start address included.
  • PAP MOS Technology papertape format, contiguous memory block, start address included.
  • SREC Motorola 8 bit S record, contiguous memory block, start address included.

Convert KIM tape to text

KIM Tape to Text is a utility to convert between binary format of a KIM-1 tape dump to a DOS text file.
The KIM tape dump is a binary file and is just a dump of part of the memory of the KIM-1.
This binary file can be a text file as used in editors Micro Ade or CW Assm/TED.
By using the tape write routine in the KIM-1 one can write an audio file on cassette.
When this audio file is captured on a PC as WAV file (22K, mono) this can be converted back to a binary memory dump with ED’s Utility KIMTape
These text files can be converted to DOS text files with this utility.

First open the binary file. If this is recognized as Micro Ade or CW Moser format, the Save as text file can be used.

Windows program.
Full source for Freepascal and Lazarus, no Windows dependencies. Compiled on 64 bits Windows 10 as 32 bit application.

Note on detection of assembler editor type
1. Micro Ade file must start with CR: when present this is Micro Ade
line nr follows 2 byte
line ends with $0D
file ends with $40
2. Assm/Ted by CW Moser starts with line number $10 $00
end of line is high bit set
There may be rare situations that a file starts with a $0D or a different line nr. You can force CW Mose detection by changing this to a sequence of $10 $00 $0D and if necessary blanks $20 to make it consistent. If in doubts: use an editor that shows the file in hex (Ultra Edit, or the free Notepad ++, Text editor PRO) and study the tape file.

Methods to get the binary file out of a Junior or KIM-1.
Read the record tape into a binary with Ed’s KIMTAPE conversion *see below). It is MS-DOS and runs fine in VDOS ( or DOsbox (slow).
Make a note of start address as shown by KIMTAPE.
Non-printing ASCII characters are filtered out of the resulting text file.

KIM Tape Convert WAV to BIN

Not my program, but so handy!

KIMTAPE v0.5 – tape conversion utility for KIM-1 and SYM-1 (2004-05-17) Local copy of

KIMTAPE allows programs stored on cassette tape to be decoded to a program file. It handles both MOS Technology KIM-1 and Synertek SYM-1 tape formats including HYPERTAPE. The reverse process – converting a program file to an audio wavefile is also possible, allowing one to produce perfectly regenerated cassettes. KIMTAPE works with 8-bit mono WAV, VOC or RAW audio files recorded
at 22050 samples per second.

Download: (MS-DOS) It is MS-DOS and runs fine in VDOS ( or DOsbox (slow).

The binary files in the KIM-1 program archives have been reproduced, from the original cassette recordings, with the tool KIMTAPE on a PC in a DOS box. See Eds DX-Forth and Utilities Page for this and other nice programs.
This program also makes it possible to reproduce the original cassette recordings that can be read by a KIM-1.

The files were made as follows: The KIM-1 cassette audio was connected to the PC audio input and (with e.g. Audacity) recorded as a wave file (mono 22KHz).
For example: qchess.wav
The wave file was then converted with KIMTAPE to a binary file (the exact content of of the KIM-1 memory when recorded).
And the KIMTAPE utility then displays load address (for example and tape ID

c:\kimtape qchess.wav qchess.bin
KIMTAPE version 0.5 17-May-04
infile: qchess.wav
outfile: qchess.BIN
Program 01 address 0200 checksum OK xxxx bytes done

This .bin file (any extension is fine!) is NOT a wave file! It contains the exact content of the KIM-1 memory when recorded. The size is exactly the number of bytes as stored in the memory of the KIM-1 and much smaller than the wave file. This binary file can be converted back to a wave file with KIMTAPE or converted to a papertape file with KIMPAPER:

C:\kimtape -M -A0200 -D01 -B2 qchess.bin qchess.wav 

As you can see: you have to specify the load address and the program ID. The B parameter indicates hypertape speed (2 here, slow)
The resulting wav file should be acceptable for the KIM-1. It is (as I have tested) acceptable as input for KIMTAPE!

All command parameters can be seen by typing KIMTAPE without parameters:

KIM-1 simulator

Work in progress, 6502/65C02 CPU emulation, disassembler, TTY, KIM-1 keypad and LEDs.


Elektor Elektuur Junior

Elektuur/Elektor and the Junior Computer and other 6502 based machines.

The Junior computer design was published by Elektuur/Elektor from 1980 on. It was published in a series of magazine articles, four books and several socalled paperware A4 booklets. Loys Nachtmann designed and developed the the Junior Computer. G.H. Nachbar did the Dutch translation of the German books. The 4 Junior books were translated into English and French as well.

The Junior design is in fact inspired by the hardware of the KIM-1, the floppy design iss based on the Ohio Scientific OS65D design. It was delivered as a kit or could be be built from only the PCB’s sold by Elektuur. Many hobbyist have built one. Later extended with an adapted version of the 8K KB9 Basic and even a disk operating system (Ohio Scientific DOS OS65D).
Many articles in the Elektuur magazine and books (1-4), a 6522 book in the same series, in Dutch, English, French and German have been published.

Quickly adopted by the dutch KIM Gebruikers Club because it was so close to the KIM-1. In the later days the number of Junior Computer users exceeded the KIM-1 users and changed the nature of the club from professional users to a hobby club. It also led to the DOS65 operating system for the Elektuur 6502 CPU board

The magazine Elektuur (the dutch name) and Elektor (the name in many european countries) surprised us in 1980 with the publication of a build-yourself 6502-based SBC. It is a design in the tradition of the KIM-1 and SYM-1: a hexadecimal keyboard, six hexadecimal led displays and KIM-1 compatible tape format.
Many Junior Computers were built, either from the PCB made by Elektuur and separate components or as a complete kit. And after we (Anton Muller and me) sent a letter to the Elektuur magazine that got published about the KIM Gebruikers Club, many hundreds Junior users joined the club.
The developments after the Junior design in Elektuur led to the EC65(K) (see below, the Elektor Computing books) and DOS65, documented on this page.

Junior Schematic


The Junior as built by Marc Engrie.

ROM contents

2708 ROM image dumped and disassembled by Ruud Baltissen

PM ROM image dumped by Rob van Oostenbrugge

Junior ROM in 2732 format made by Rob van Oostenbrugge
This ROM dump only contains the monitor parts, not the editor nor assembler.

A 2732 EPROM can be used instead of the 2708 EPROM when:you perform the following:
– cut the traces +12 and -5V
– K6 to the VIA,
– k7 to the EPROM.but leave k7 to the 7401 intact for the STEP function.
– /cs from VIA to K3. to move the VIA to page 0E (jumps in the eprom are adapted for that)
– /OE from the2732 to ground
– A10 and A11 of the 2732 to the adresbus
– /cs from the 2732 via an inverter to A12 , note that there are two unused ports in the 7402 with grounded inputs,: cut those! and add a pullup resistor.

The Junior was sold as a kit by the firm Musicprint, read here the extra instructions in the kit.


In a package with Elektor hardware Octopus cards I recently bought, I found a little book and a floppy with Junior tape dumps. In binary format! Made with what I think is an 68000/Atari/Amiga program. it is also included. The files could be restored back to tape with the Ed’s DX-Forth and Utilities.

Download here the archive

Included are sources and programs like
– Junior PM and TM
– memory test
– Micro Ade, KIM-1 and Junior version, also in source format and extended format
– Clock source program
– CW Moser assembler/editor, also in source
– Forth, Comal
– SYM Basic adapted to Junior

See the included juniortapes.txt for a complete listing of First book of KIM programs adapted to Junior

Build a Junior

Musicprint cassette interface

It took Elektuur some time and the potential user a lot of money to add a cassette interface tot the Junior design, Many users therefore bought the scalled musicprint cassette interface. See here the description and circuit design.

Elektuur articles

This is the list of (dutch)articles and books and paperware by Elektuur devoted to the 6502 CPU. Downloadable documents are dutch versions only!

Year of issue Issue-Page Article Download as:
1980 3-26 Junior-computer
The introduction article
PDF file of the first two (dutch) articles 3-26 and 4-72 with the complete hardware design
1978 1983 Elekterminal
All articles in one
PDF file of issues 181 to 231
1980 and 1981 Junior Computer as published in the french Elektor First article (french) and the I/O expansion (1981) in PDF format Elektuur Junior
Junior Computer as published in the german Elektor (thanks Wolfgang Robel) First article about the german Junior May 1980
June 1980 article
September 1980 article
October 1980 article
Januari 1982 article
German article Junior
4-72 Junior-computer hexadecimal monitor dump
5-66 KIM Gebruikers Club promotion! nogmaals: junior-computer nog wat aanvullende gegevens
8-26 RS 232 interface
9-48 RAM/EPROM kaart 8K RAM + 4,8,16K EPROM All other Elektuur Junior articles 1980
10-42 meer junior-geheugen, memory decode for RAM/EPROM card
11-71 junior groeit!
1981 2-54 junior-tekst, show text on led displays All other Elektuur Junior articles 1981
3-54 junior-journaal, practical tips
4-41 junior-hardware kompleet (PDF file) junior-hardware kompleet (PDF file)
4-52 junior-software aangevuld
5-56 junior-uitbreidingen bouwrijp (PDF file) junior-uitbreidingen bouwrijp (PDF file)
6-53 Junior Computer als Voltmeter (G.Sullivan)
1982 1-58 EPROMmer (P.R. Boldt) All Elektuur Junior articles 1982
3-47 Junior spreekt Basic, adapt KIM KB-9 Basic to Junior
4-46 mini-EPROM-kaart
4-50 dynamische RAM-kaart
5-39 Software-uitpluizer (disassembler)
5-62 PSS Prive Software Service (EPROMmer)
5-67 Mini-teller met microprocesssor
7-59 Junior-vektoren ophalen (R. Mattysek)
7-46 single-cycle voor junior-computer (E.Kytzia)
10-59 Van 6502 naar 6809
11-58 Floppy-disk interface voor junior en andere 6502-computers deel 1
12-26 floppy-disk interface deel 2 (Ohio Scientific DOS)
1983 1-66 verkeerslichtensturing (D. Herzberg) All Elektuur Junior articles 1983
3-28 universele geheugenkaart > universele geheugenkaart Elektuur Junior
5-60 morse-dekoder All Elektuur Junior articles 1983
5-37 junior-programmatester
6-48 RTTY-dekoder
7-73 busy-indicator voor junior
7-79 vektor-aansturing voor junior
9-58 VDU-kaart
sept VDU card Elektor UK VDU card Thanks to Malcolm Brown
nov Universal terminal Elektor UK Universal terminal Thanks to Malcolm Brown
9-66 de muzikale junior
9-74 64K op de dynamische RAM-kaart
10-57 basicode-2 voor de junior
10-72 EPROMmer zonder interfacekaart
1984 2-75 Basicode-2 voor Junior met VDU-kaart All Elektuur Junior articles 1984
2-66 6502-tracer
3-40 Tapemonitor uitbreiding
4-53 ID-list
4-71 motorschakeling voor floppy drives
7-68 2716 voor 2708
8-12 start-omleiding voor 6502
8-15 beeldruiskiller
9-72 DOS-uitbreidingen
11-33 de 6845 geprogrammeerd


(french covers thanks to Gerard Mizzi, english covers thanks to Ruud Baltissen, spanish cover and scan thanks Joseba Elpalza)

OCR’ed versions of the books can be found here, thanks to Keith Howell. All four dutch and all four english books!

Junior computer 1
Elektuur Junior boek 1 (NL)
Elektor Junior book 1 (English)
Elektor Junior book 1 (Spanish)
Elektuur Junior Elektuur Junior
Elektuur Junior Elektuur JuniorElektuur Junior
Junior computer 2
Elektuur Junior boek 2 (NL)
Elektor Junior book 2 (English)
Elektuur Junior Elektuur Junior
Elektuur Junior Elektuur Junior
Junior computer 3
Elektuur Junior boek 3 (NL)
Elektuur Junior Elektuur Junior
Elektuur Junior
Junior computer 4
Elektuur Junior boek 4 (NL)
Elektor Junior book 4 (English)

Elektuur Junior Elektuur Junior
Junior computer VIA 6522 Elektuur Junior
Junior computer Paperware1 – source listings Junior2 – source listing floppy drive bootloader

3 – universele terminal

4 – aansluiten VDU kaart

(met dank aan Ruud Baltissen)

Elektuur Computing 1
Octopus/Samson 6502 computer
Elektuur Computing 2
More 6502 computer
Elektuur Computing 3
More 6502 computer
Elektuur Computing 4
EC65K and more
Elektuur Computing 5
Z80 and more 6502 hardware and software

Download the EC65 system ROM and Character generator ROM here.

Radio Bulletin

The dutch magazine Radio Bulletin (RB, RB Electronics) has a long history, way back to the beginning years of electronics long before the second world war. The name was derived from what electronics meant for amateurs then: building radios yourself.
It was published by Uitgeverij de Muiderkring, a publishing company in the Amroh group of companies.

The magazine was published in large volumes in the years 1970-1990, due to the popularity of do-it-yourself electronics and audio. Also the beginning of the microprocessor revolution was adequately covered and the great years of the hobbycomputers 1980-1990 were contributing to the success. Besides the magazine Uitgeverij de Muiderkring published many books on electronics. After 1990 the success faded and the magazine left the mass market and stopped in 2003. The publishing company Uitgeverij de Muiderkring, together with Amroh, went bankrupt in 2002 (I lived closely to the last location and saw the empty offices when passing by).

In 1977 Dick de Boer joined the staff of RB and introduced the readers to microprocessors and in particular the 6502 and the KIM-1. Also the KIM Gebruikers Club and the HCC were founded that year and RB started to write articles about all this exciting new developments!

I was then already a freelance writer about electronics but Dick made me study the microcomputer such as the KIM-1 and made me join the KIM
Gebruikers Club and the HCC (member 760 member). Dick de Boer, his successor Paul de Beer and me (Hans Otten) and others wrote many articles about the KIM-1 and related 6502 based systems for Radio Bulletin. Especially Dick wrote good introduction articles and developed sophisticated hardware and software like a graphical display. After leaving the magazine he became a software engineer and helped me also to my first job as software engineer in 1980. Me and Paul de Beer concentrated more on expanding 6502 systems like the KIM-1 with memory (RAM, ROM) and I/O cards like PIA, VIA and ACIA and mass-storage such as the Mini Digital Cassette Recorder. The bus of this expansion system was the so called BEM-bus, a 31-pin DIN41617 connector.

All these articles are downloadable here,  as they describe my KIM system and many others since the prints sold quite well. As you can see in the following long list the KIM and the 6502 played a major role in the microprocessor revolution starting in 1977 and lasting until 1985 for Radio Bulletin.
See my RB page for the other articles I have written for Radio Bulletin.

Here a selection of interesting 6502/KIM and general RB electronics/computer articles, written by me and others, (dutch) in Radio Bulletin of the period 1977 to 1987. Note that some articles were reprinted in the CB specials (see below).

Grote prijsvraag, het begin van mijn redactionele bijdragen aan Radio Bulletin
De Microprocessor, mei juli 1977, Dick de Boer
Digitale dokatimer, oktober 1977, Hans Otten
Geheugenuitbreiding voor de KIM, November 1977, Dick de Boer
De KIM-1 aanschaf via Radio Bulletin
De KIM-1, Augustus 1977, D.M. de Boer
Mastermind op de KIM-1, December 1977, J.M. van der Peijl en D.M. de Boer
Melodiant, Augustus 1977, D.M. de Boer
Microgebeuren Augustus 1977, a.o. KIM gg club
Microgebeuren November 1977, BEM Brutech, Visser Assembling Electronics
De Videoscoop, December 1977, Hans Otten
Zelf programmas maken, September 1977, D.M. de Boer
Automatische register uitlezing, Februari 1978, D.M. de Boer
De VIM getest, November 1978
Digitale Voltmeter IC’s, Augustus 1978, Hans Otten
Press Communication Award Dick de Boer
Eprom programmeer apparaat, Juni Juli 1978, J.M. van der Peijl
Grafisch TV-display 1978 1979, D.M. de Boer
Microgebeuren,HCC, Ing Bureau Koopmand nieuws TVT-6, Memory+, First Book of KIM, Mei 1978
Programmeren stap voor stap, 1978, 1979 (zie ook RB CB Special voor laatste deel, D.M. de Boer
Televisiespelletjes, October 1978, Hans Otten
Zelf een print maken, October 1978, Hans Otten
Cosmicos computer voor zelfbouw, H.B. Stuurman, boek en serie
De 8088, November 1979, Hans Otten
De MCS Alpha 1 getest, Augustus 1979, Hans Otten
De Challenger Ohio 1P getest, Juli 1979, Hans Otten/a>
De Compucolor II goed getest, Juni 1979, Hans Otten
De Heathkit H14 printer, Oktober 1979, D.M. de Boer
De PET getest, April 1979, Hans Otten
De TRS 80 getest, November 1979, Hans Otten
Geheugenuitbreiding voor de KIM, September October 1979, Hans Otten
Het Heathkit 8 systeem getest, Juli 1979, Hans Otten
Letters op het grafisch display, Mei Juni Juli 1979, D.M. de Boer
Memory plus getest, Mei 1979, Hans Otten
Morse decodering met de KIM, juli Augustus 1979, M.B. Immerzeel
Professioneel toetsenbord voor de PET, November 1979, Hans Otten
Zelf voedingen ontwerpen en bouwen, Januari 1979 – Januari 1980, Hans Otten
Zero Page shifter, Augustus 1979, D.M. de Boer
Jaarinhoud 1980
Amicos systeem getest, September 1980, Hans Otten
Overdruk Amicos systeem getest, Hans Otten
Basic versus Pascal, December 1980, Hans Otten
Baudrate generator, Augustus 1980, Hans Otten
BEM Impact 1000, Januari 1980, Hans Otten
De Apple II getest, Januari 1980, Hans Otten
De KTM2 getest, April 1980, Hans Otten
De PC100 getest (AIM 65), Augustus 1980, Hans Otten
Hexadecimaal toetsenbord 6502 systemen, September 1980, D. Hul
Kim timer en klok, Mei 1980, Herman Perk
Knutselen met cassettedeck, Maart 1980, Hans Otten
Logitester, Augustus 1980, Hans Otten
Microgebeuren April 1980, BEM Brutech
Microgebeuren April 1980, BEM Brutech
Persprijs H.B. Stuurman , eervolle vermelding Hans Otten, November 1980
Samson en Satellite getest, November 1980, Hans Otten
Sinclair ZX80 getest, Januari 1980, Hans Otten
U/ART schakeling, Juni 1980, Hans Otten
Video modulatoren getest, Maart 1980, Hans Otten
WH89 getest, Juni 1980, Hans Otten
Jaarinhoud 1981