I started writing about my interest in electronic since 1970. And in 1977 the magazine (Dick de Boer!) introduced me to the KIM-1, and that enhanced my joy with electronics with computing.
At the university in these days electronics and computer science also came together.

We have published many articles around the KIM-1. Alas in Dutch and only on paper. Published on this website, see the Radio Bulletin pages.

Many of the articles deserve a wider public, the KIM-1 and its clones are used by a broad international public.
So I started a new project: translate the articles to English and make the software available in assembler and binary format.

See the archive here

My KIM-1 system was based upon what we had published in Radio Bulletin. These articles by Dick de Boer, Paul de Beer and me document how the expanded system evolved, using an extended version of the BEM bus.

Articles here:

• The KIM-1
• Write your own programs
• Programming step by step
• Memory expansion for the KIM
• EPROM Programmer
• Tinkering wih a Casssete deck
• Memory expansion for the KIM 4K RAM
• Motherboard for 6502 systems
• ACIA6850 Serial in- and output
• Parallel in- and output PIA 6820 and and VIA 6522
• Mini-digital Cassetterecorder interface for the 6502
• 4K EPROM card
• Graphical TV Display
• Letters (Characters) on the Graphical TV Display
• Lines on the Graphical TV Display
• ASCII characters on the Graphical TV Display
• Graphical TV Display Monitor
• Digiscope for 6502 systems
• 48K Dynamic RAM card
• 48K RAM card for 6502 systems

De KIM-1

The article that started the KIM-1 articles!

	De KIM-1 Radio Bulletin Augustus 1977 Original article
	The KIM-1 RB Aug 1977 English
	De KIM-1 RB Aug 1977 Dutch

Write your own programs

Radio Bulletin September 1977

The most enjoyable work is of course writing your own programs, making the KIM I do exactly what you want. Now, programming is not that easy for someone who has never done it before. Especially at the beginning, the aspiring programmer works in such a disorganised way that in the end he no longer knows which instruction is at which address. It is therefore important to set up a program in a clear, orderly way and to write down every change. In this article we will use an example to show how this is done. However, we leave the exact working-out to the reader, because here too it is certainly true: practice is the best teacher!!!

	Zelf programmas maken Radio Bulletin september 1977 Original article
	Writing your own programs English RB Sept 1977
	Zelf programmas maken Dutch

Programming step by step

A five part article in Radio Bulletin 1978 to 1979
Since RB’s KIM campaign in August of last year, the number of KIM owners has grown considerably. Readers’ reactions show that some of the new KIM owners are already getting the hang of programming quite well. Another group, however, is clearly lagging behind: the people who cannot find the ‘beginning’. That is very understandable when you consider that, although the computer is built from electronics, programming is completely new territory for many. In this article RB will therefore try to help this group on their way.

	Programmeren stap voor stap Radio Bulletin 1978 to 1979
	Programmeren stap voor stap Dutch
	Programming step by step English
/	Programming step by step sources

Memory expansion for the KIM

Radio Bulletin 1977/ Introduction of the BEM bus with a 1K RAM card.

Although the 1K memory space of the KIM 1 is very generous for a beginning programmer, sooner or later the need for more memory will arise. This allows larger programs to be written, or more programs to be held in memory at the same time.
There are several ways to expand the memory. You can buy a number of ICs yourself and mount them on a home-made circuit board, which is by far the cheapest solution. The nicest solution is simply to buy a ready-made memory card; you then have a professional piece of work, with the reliability that goes with it.
A 1K EPROM card is designed, based upon the BEM bus.

	Geheugenuitbreiding voor de KIM Radio Bulletin November 1977 Original article
	Memory expansion for the KIM RB Nov 77 English
	Geheugenuitbreiding KIM Dutch
	Memory expansion for the KIM source and binary

EPROM Programmer

Radio Bulletin 1978 J.M. v.d. Peijl
The EPROM (Erasable PROM) can also be programmed by the user. In addition, it can be erased again using ultraviolet light. Thus an EPROM containing obsolete or outdated programs can simply be erased and reprogrammed. The most popular EPROM at present is the 2708 (1K byte), which has fallen considerably in price recently, partly because of its successors, the 2716 and 2732, with 2K and 4K bytes respectively. Programming such an EPROM is a task that the KIM can handle very well. In this first part you can read how, by adding a few simple circuits, the KIM takes over the job of an expensive PROM programmer. We will describe several practical versions.

	Eprom programmeer apparaat Radio Bulletin Juni Juli 1978 original article
	EPROM programmer Radio Bulletin June July 1978 English
	Eprom programmeer apparaat Radio Bulletin Juni Juli 1978 Dutch
	Eprom programmer source and binary Radio Bulletin Juni Juli 1978 Dutch

Audio cassette recorder

Radio Bulletin March 1980

Accompanied by the slogan ‘Tophit 1980’, Radio-Service Twenthe is offering a built-in front-loader cassette deck for the low price of f 32.50. Radio-Service Twenthe often manages to offer interesting industrial surplus to the amateur at a reasonable price, and this cassette deck is another example of that. A handy tinkerer can easily turn this cassette deck into a mono cassette recorder; for personal computer users this is a golden opportunity to get hold of suitable cassette recorders with a tape mechanism.

	Knutselen met een cassettedeck Radio Bulletin maart 1980 original article
	Tinkering with a cassettedeck RB March 1980 English
	Knutselen met een cassettedeck RB March 1980 Dutch

Memory Expansion for the KIM

With 4K RAM card and busbuffer print.
Radio Bulletin September October 1979

Memory expansion for the KIM has already been discussed twice. The first time, in the November 1977 issue, it was shown how RAM could be added with the BEM-1 board, a kit for 2K of static RAM. The second time was in the July 1978 issue, when a board design for a 2K EPROM card was published, with the same bus connections as the BEM-1 card. This series now continues with a 4K static RAM board, also with the same bus. Connecting the RAM to the KIM requires address decoding and a bus buffer. A board has been designed for this as well.

The 4K RAM production.

The 4K RAM prototype.

	Geheugenuitbreiding voor de KIM Radio Bulletin September October 1979 Original article
	Memory expansion English
	Geheugenuitbreiding Dutch

Motherboard, memory support for 6502 systems

Radio Bulletin July 1981

Radio Bulletin has already described several ways to expand the standard memory of 6502 systems such as the KIM. Published so far are a 2 Kbyte static RAM card, the BEM-1 board (November 1977), a 2 Kbyte EPROM card (June and July 1978) and a 4 Kbyte static RAM card (September and October 1979). All these designs use the bus as used on the BEM-1 board, but with a number of additions, which will be needed mainly for the 4 Kbyte EPROM board in a forthcoming issue. This article describes a motherboard into which all these cards can be plugged.

	Moederprint for 6502 systems Radio Bulletin Juli 1981 Original article
	Motherprint for 6502 systems English
	Moederprint voor 6502 systemen Dutch

Parallel in- and output PIA 6820 and and VIA 6522

Radio Bulletin May 1984
The subject of this article is a family of parallel input/output ICs: the PIA 6820, 6821, 6520 and the VIA 6522. These are widely used ICs, and not only in 6500 and 6800 microprocessor systems. Besides the general hardware characteristics of the PIA and the VIA, a practical implementation is presented

Prototype of PIA VIA card

	Parallele in- en uitvoer VIA en PIA Radio Bulletin May 1984 Original article
	Parallel in- and output English
	Parallele in- en uitvoer Dutch

ACIA6850 Serial in- and output

Radio Bulletin September October November 1983



Prototype serial interface

	ACIA6850 Seriele in- en uitvoer Radio Bulletin September – November 1983
	ACIA6850 Serial in- and output RB sept oct nov 1983 Dutch
	ACIA6850 Serial in- and output RB sept oct nov 1983 English
	ACIA6850 examples source

Mini-digital cassette recorder interface for the 6502

This article describes an interface between a 6502 computer and one or more MDCRs, and a number of elementary routines in 6502 assembler for using the MDCR. The software has deliberately been developed to be as universal as possible

	MDCR voor de 6502 Radio Bulletin April 1984 original article
	MDCR for the 6502 RB April 1984 English
	MDCR voor de 6502 RB April 1984 Dutch
	Mini-digital interface MDR source With original listing as scan
	Philips-MDCR_Service-Manual

4K EPROM card

Radio Bulletin September 1981

As part of further memory expansion for 6502-based systems such as the KIM, Junior, SYM, etc., a 4 Kbyte EPROM card is described here. It is suitable for two types of EPROM, the TMS2516 and the 2716, the latter being the most common. The board plugs into the motherboard published in a previous issue of Radio Bulletin. Combined with the EPROM programmer (RB December 1980 and January 1981), this gives you the tools needed to put programs such as an assembler, a high-level programming language, a bootstrap loader or your own developments into ROM and run them from there.

	4 Kbytes EPROM-kaart Radio Bulletin september 1981 Original article
	4K EPROM Card English
	4K EPROM Kaart Dutch

Graphical TV Display

Radio Bulletin, 4 parts, September 1978 – November 1978 – February 1979 – March 1979

Just imagine: an ordinary TV on which you can make your own drawings. These can range from plain text and graphical representations of mathematical functions to a drawing made by a toddler. For this purpose the TV screen has been divided into a grid of 256 × 256 dots!! Such a grid gives roughly the maximum resolution that can be displayed on an ordinary TV (without interlacing). The applications are countless. The computer hobbyist gets a particularly fine output device, a kind of combination of plotter and teletype. For those who do not own a computer, it is possible to expand this unit into a hobby computer.

My Graphic Dispkay with the hardware scroll addition.

	Grafisch TV-display Original articles Radio Bulletin 1978 1979
	Graphical TV Display English
	Graphical TV Display Dutch

ASCII characters on the Graphical Display

A subroutine to display an ASCII character (upper and lowercase) on the Graphical Display.
Unpublished code, 1983 Hans Otten

GRDEV source full ASCII set/a>

Characters (Letters) on the Graphic Display

Radio Bulletin May June July 1981

In the previous series of articles on the home-built graphic TV display, a lot of attention was paid to the hardware of this display. Two important routines were also discussed, namely switching on or off one of the 65536 dots and clearing the picture. But… a display is not a display if no text can be shown on it. That is why this article presents what is perhaps the most important piece of software written for this display: ‘drawing’ letters, with unprecedented flexibility.

	Letters op het grafisch display Radio Bulletin mei juni juli 1979 Original article
	Letters on the Graphical Display English
	Letters on the Graphical Display Dutch
	Characters on the graphic display sources

Lines on the Graphical Display

This article describes a program that draws straight lines on the graphic display. Only the start and end points of the line need to be entered; the program then draws the line.

	Lijnen op het grafisch display Radio Bulletin Februari 1982 Original article
	Lines on the graphic display English
	Lijnen op het grafisch display Dutch
	Lines on the graphical display sources

Graphical Display Monitor

Radio Bulletin 1981 – 1984 4 parts

The set-up is as follows. The complete package consists largely of subroutines that are controlled by a small main program. These routines are simply placed one after the other in memory. Those who do not want a complete monitor can use these subroutines separately, since they can also prove their worth on their own. This produces a “subroutine arsenal”. Those who do want a complete machine-language monitor, however, will have to make a few changes to, and additions to, the hardware.
1. As you may know, it is possible to build a hardware scroll-up on the GD. This needs 4 ICs. Without this extension the monitor does not work.
2. The monitor needs a larger keyboard (28 keys). I may assume, however, that if you do not have an ASCII keyboard you have long been planning to buy a more extensive keyboard. Further on in this article a keyboard is described that is very cheap and more than adequate (for about f 30.00 you have a well-working keyboard). A real ASCII keyboard is of course still recommended.
3. Not necessary, but very handy, is a circuit that allows a loudspeaker to be switched on and off by software. This can be useful in combination with the monitor (think for example of a beep after CRLF has been given).

	Grafisch display monitor voor de KIM Radio Bulletin 1979 1981 original rticle
	Graphic display monitor for the KIM English
	Graphic display – monitor for the KIM Dutch
	Graphical display monitor KIM sources

Digiscope for 6502 systems

Radio Bulletin April 1983

Those who have a Graphic Display and a computer system based on the 6502 will discover in this article that the possibilities of this combination are almost unlimited. The January 1980 issue described a frequency meter, which once again showed that a computer can prove its worth in the hobbyist’s electronics lab. The program discussed here, as an addition to the frequency meter, will for many be an answer to the question: “Should I buy a computer?” What we have here is a so-called “digiscope”. This is a kind of oscilloscope that makes digital signals visible on the graphic display.

>

	Digiscope voor 6502 systemen Radio Bulletin April 1983 Original article
	Digiscope for 6502 systems RB April 1983 English
	Digiscope for 6502 systems RB April 1983 Dutch
	Digiscope for 6502 source

48K RAM card

Radio Bulletin 1982

If you want to work with Basic, Forth, editors etc., you need a lot of memory. It makes no sense to build this up from 4K memory cards. A cheaper and better solution is to use dynamic RAM ICs.
The industry-standard 4116 is a 16K × 1 dynamic RAM chip. With eight of these 16-pin ICs you get 16 Kbyte, and with 24 ICs 48 Kbyte. The dynamic RAM card for the 1802 fits into a bus connector of the Cosmicos computer. The card is also easy to use with other 1802 systems; it is then connected with 24 wires.
What is remarkable is the simplicity of the dynamic RAM card. This is because a special IC has been used for timing and refresh: the Intel 8202. Since this controller and the memory ICs functionally form a self-contained unit, use with e.g. KIM or Junior computers is certainly possible by adapting the addressing logic. You don’t need to design a PCB for that part – no small job saved.

	48K RAM card for 1802 systems Original article, Cosmicos series
	Cosmicos 48K dyn ram card English
	Cosmicos 48K dyn ram kaart Dutch

48K RAM card Interface for the 6502

Radio Bulletin September 1983
After tinkering for some time with 4K RAM cards and the accompanying tangle of wires
and connections, my eye was caught by the 48K RAM card for the 1802 published in the
March 1982 and following issues of RB. This o%ered the chance to solve the memory
problem once and for all, so the possibility of adapting this card to the 6502 processor
was studied. By leaving a number of ICs o% the original board and adding a small
interface in the space freed up, you get 48K of RAM for your 6502 system – a real wealth.

	48K ram kaart voor de 6502 Radio Bulletin September 1983 Original article
	48K ram card voor 6502 English
	48K ram kaart voor 6502 Dutch

Published in the Byte Book of Computer Music, 1979. Written by Peter H. Myers.

Scanned article here.

The listing is converted to MOS Technology standard assembler source. The resulting code compared to the publsihed code.
Here and archive with source and papertape binary.\

Published in the Byte Book of Computer Music, 1979. Written by Peter H. Myers.

Scanned article here.

The listing is converted to MOS Technology standard assembler source. The resulting code compared to the publsihed code.
Here and archive with source and papertape binary.\

The original articles were scanned from the magazine pages. converted back to text with OCR and translated to English.
The documents in Dutch and English are also published again in PDF format.

If a program listing was included the assembler source is reconstructed in modern MOS Technology syntax. The binary output is compared to the printed binary code and a papertape formatted binary is included.
The articles describing the expansions we designed for our KIM-1s at the magazine are on a separate page.

Downloads available for every article:
– the original scanned article in Dutch
– the Dutch OCR’ed and recreated article
– the English, translated from the OCR result, and recreated article
– an archive with source and binary if applicable

Articles here:

• The KIM-1
• Write your own programs
• Programming step by step
• Mastermind on the KIM
• Morse decoding with the KIM
• Melodiant
• Frequencymeter
• KIM Timer and Clock
• Zero page shifter
• Telex Monitor Program
• Gregorian Clock
• PIA Buffer
• Automatic Register Readout
• Mini-assembler
• My KIM-1 expansions in Radio Bulletin

De KIM-1

The article that started the KIM-1 articles!

	De KIM-1 Radio Bulletin Augustus 1977 Original article
	The KIM-1 RB Aug 1977 English
	De KIM-1 RB Aug 1977 Dutch

Write your own programs

Radio Bulletin September 1977

The most enjoyable work is of course writing your own programs, making the KIM I do exactly what you want. Now, programming is not that easy for someone who has never done it before. Especially at the beginning, the aspiring programmer works in such a disorganised way that in the end he no longer knows which instruction is at which address. It is therefore important to set up a program in a clear, orderly way and to write down every change. In this article we will use an example to show how this is done. However, we leave the exact working-out to the reader, because here too it is certainly true: practice is the best teacher!!!

	Zelf programmas maken Radio Bulletin september 1977 Original article
	Writing your own programs English RB Sept 1977
	Zelf programmas maken Dutch

Programming step by step

A five part article in Radio Bulletin 1978 to 1979
Since RB’s KIM campaign in August of last year, the number of KIM owners has grown considerably. Readers’ reactions show that some of the new KIM owners are already getting the hang of programming quite well. Another group, however, is clearly lagging behind: the people who cannot find the ‘beginning’. That is very understandable when you consider that, although the computer is built from electronics, programming is completely new territory for many. In this article RB will therefore try to help this group on their way.

	Programmeren stap voor stap Radio Bulletin 1978 to 1979
	Programmeren stap voor stap Dutch
	Programming step by step English
/	Programming step by step sources

Mastermind on the KIM

Radio Bulletin December 1977

You are probably familiar with the well-known game Mastermind. Normally this game is played by two people, with only one person actively trying to guess a hidden code. The second person has the passive task of indicating, with black and white pegs, whether the chosen colours are correct and whether they are in the right positions. Replace the colours with digits, the black and white pegs with letters, and the KIM takes the place of the passive player. At your command, it chooses a secret colour combination and uses letters to indicate how many digits have been correctly guessed. A special “cheat button” makes it possible to peek secretly behind the screen; the consequence, however, is that the turn counter is increased by 30 points.

Runs on the unexpanded KIM-1 with keypad and seven segment display.

	Mastermind on the KIM Radio Bulletin 1977 original scan
	Mastermind on the KIM Radio Bulletin 1977 English
	Mastermind on the KIM Radio Bulletin 1977 Dutch
	Mastermind source and binary

Morse decoding with the KIM

Radio Bulletin July August 1979

It may be quite nice to be able to say that you are the owner of a microcomputer (if things continue as they are now, in a few years this will be just as commonplace as owning a pocket calculator is today), but even nicer is to also own programs and to be able to spend a number of useful and above all pleasant hours with the device. The following program, written for the KIM, may contribute to this. It makes it possible to display received Morse signals as ‘readable writing’ on the KIM display. Although with a seven-segment display by no means all letters and punctuation marks can be formed, and therefore certain symbols had to be found for these characters, after some practice it is quite possible to read messages sent in Morse code from the display. The program can be used not only for displaying received messages, but also for practising sending and for checking the sending technique. From what is shown on the display one can determine what mistakes are being made while sending

	Morse decodering met de KIM July Augustus 1979 original scan
	Morse decoding with the KIM July Augustus 79 Radio Bulletin English
	Morse decodering met de KIM Juli augustis 1979 Dutch
	Morse decoding with the KIM source and binary
	Morse decoding circuit in Kicad By Roland van Straten

Melodiant

Radio Bulletin august 1977. Dick Boer.

The Melodiant plays a complete melody of up to 256 tones on a command given by you. The display shows which note is being sounded. This makes the Melodiant a very versatile instrument. For example, you can play duets together with the Melodiant by typing in one of the two voices beforehand. The advantage over a tape recorder is that the melody can be played at any desired tempo, which can make practicing easier. What about the Melodiant as a music teacher? A note appears on the display, and the student must try to sing or whistle that note. Afterwards, the loudspeaker can be switched on to check. The Melodiant will also flawlessly play back the most difficult rhythms, slow or fast as needed.
But the possibilities do not end there. We can make the Melodiant play so fast that the individual tones are no longer recognizable. This can produce the strangest sound effects.

	Melodiant Radio Bulletin Augustus 1977 original scan
	Melodiant August 1977 Radio Bulletin English
	Melodiant Augustus 1977 Radio Bulletin Dutch
	Melodiant Radio Bulletin Aug 1977 source and binary

Frequencymeter

Radio Bulletin January 1981 M. Dohmen, R. Koekoek

The program described here can measure a frequency up to, mind you, 100 kHz, with a deviation of no more than one cycle in 65536. The frequency is read out in five digits. The program was written for the KIM, but is also well suited to other 6502 microcomputers, notably the SYM and the Junior. Once started, the program measures a frequency continuously when key “6” is pressed, and once when key “0” is pressed.

	Frequentiemeter Radio Bulletin Januari 1981/td>
	Frequency meter Radio BulletinJanuary 1981 English
	Frequency meter Radio BulletinJanuary 1981 Dutch
	frequencymeter source and binary

KIM Timer and Clock, Radio Bulletin May 1980, Herman Perk

While working with the KIM I once encountered the problem that a clock had to be maintained during the execution of a program. Not for the KIM itself, but for a system with the TIM monitor, namely the BEM-bus-based 6502 system from the company Brutech, which is highly recommended for its high quality and well-thought-out design (hence the prices). At the end of 1978, however, both the KIM and the BEM system were still lacking 6522 VIAs with their versatile timers, unlike the SYM and AIM-65. Worse still, the TIM monitor uses the only timer available in the system for communication with the terminal. If I nevertheless wanted to use the 6530 timer for the clock, I had to write my own program for communication, based on the so-called software timing loops. I did so, since I no longer needed TIM itself for the result. As for the timer (those of the 6530 and 6532 are identical), the “obvious” operating instructions say nothing about a possible “free-running” mode as would be usual for a clock and as is described for the 6522

	KIM Timer and Clock Radio Bulletin May 1980 Original article
KIM Timer and Clock May 1980	KIM Timer and Clock May 1980 Radio Bulletin May 1980 English
	KIM Timer and Clock May 1980 Radio Bulletin May 1980 Dutch
	KIM Timer and Clock source and binay

Zero page Shifter

D.M. de Boer, Augustus 1979 Radio Bulletin

	Zero Page shifter Original article
	Zeropage shifter August 1979 English
	Zeropage shifter August 1979 Dutch
	Zeropage shifter RB August 1979 Source and binary

Telex Monitor Program

Radio Bulletin April June 1981 M.B. Immerzeel

Those who own a “simple” microcomputer such as the KIM or the SYM, and who also own a telex transceiver, will long since have thought about using the telex as a terminal and may already have a program for that purpose. However, most of these programs are limited to noting down addresses with their contents one below the other, and are therefore not particularly economical with paper. The program described below offers the following possibilities:
a. Loading a program in hexadecimal code.
b. Loading ASCII characters.
c. Printing memory contents as hexadecimal numbers.
d. Printing ASCII characters.
e. Starting a program.

	Original article Radio Bulletin April June 1981
	Telex Monitor Program Ènglish
Telex Monitor Program Dutch	Telex monitor RB June 1981 dutch
	Telex Monitor Program source and binary

Gregorian Clock

Radio Bulletin May 1981

This clock program is very short and will certainly prove useful to many people. It counts in decimal and keeps track, in decimal, of quarter seconds, seconds, minutes, hours, day of the week, date, month, year and century. Leap years are taken into account!

	Gregoriaanse klok Original article Radio Bulletin May 1981
	Gregorian Clock English
	Gregorian clock Dutch
	Gregorian clock source and binary

PIA Buffer

Radio Bulletin November 1983

The outputs of the user PIA are not suitable for connecting devices to. A buffer stage is necessary to achieve this. I believe that the term “student-proof” applies to this circuit

	PIA-buffer Original article Radio Bulletin November 1983
	PIA Buffer Nov 1983 Dutch
	PIA Buffer Nov 1983 English

Automatic Register Readout

Radio Bulletin February 1978

When developing programs on the KIM 1, we can make use of the single-step facility that the KIM has. After each press of the ‘GO’ key, one instruction is executed.
The display then shows the address of the next instruction to be executed. After each step we can check the contents of the various registers. A drawback is that an address has to be entered for each register, which makes checking rather cumbersome. This article describes a program that ensures that, while the ‘GO’ key is held down, the contents of 3 memory locations of your choice appear on the display simultaneously. When the key is released, the address of the next instruction to be executed appears again.

	Automatische register uitlezing Orginal article
	Automatic Register Readout English
	Automatisch Register Uitlezen Dutch
	Automatic Register Readout Source and binary

Mini-assembler

Radio Bulletin March April 1981

Are you annoyed time and again by having to calculate branch offsets for branch instructions? We are not anymore, because the “Mini-assembler” described here makes programming the KIM considerably easier in many respects. The program itself requires only 254 bytes of RAM/ROM and will therefore be a welcome aid to many KIM users when writing other programs.

	Mini-assembler Original article Radio Bulletin March April 1981
	Mini-assembler RB March April 1981 English
	Mini-assembler RB March April 1981 Dutch
	Mini-assembler RB March April 1981 sources and binaries

Acquired August 2026, as built in a KIM-1 with KIMSI system.
Page updated September 2026 with scans and KIM-1 source of the original manual and brochure.

I acquired a KIMSI in August 2026. It was build into a plexiglas/aluminium case, with a KIM-1 (Rev G) and a ‘microcalculator board’. I took the system apart, no room to store the big ugly thing.

Acquired August 2026, as built in a KIM-1 with KIMSI system.
Page updated September 2026 with scans and KIM-1 source of the original manual and brochure.

Downloads

	MICROCALCULATOR MODEL-5 Handbook
	MICROCALCULATOR MODEL-5 Brochure
	KIM-1 source of control program Typed in from the manual, errors corrected in source while checking with binary code

Every other version is a derivate, in the 80ties or in the past years.

There are also sources of Microsoft Basic for the 6502. The official source, in PDP-11 MACRO source format has been declared open not so long ago.
The title is ‘M6502 8K VER 1.1 BY MICRO-SOFT’. Yes the name of the company was originally MICRO-SOFT!

Many years before the official source, Michael Steyl of pagetable.com reconstructed the source, based upon my binary dump. A perfect start to create derivate versions!

Versions known in the 80ties

• KB-9
  Created by Microsoft, only distributed by Johnson Computers (afaik). Binary available.
  On the tape label: 2000-4260 ID #01 St 4065
  Oldest known documentation available, scanned.
• KB-6
  Mentioned in the documentation of ID #01. Not available.
  6 digit precision floating point, smaller in size.
• KB-9 ID #101
  Distributed by Johnson Computers
  On the tape label: 2000-437D ID #101 St 4065 S/N 217 and 233. Binary not available (yet).
  Mentioned in the documentation of the versions distributed by Johnson Computer with ID #101. Binary not available. Two versions of the documentation known and scanned.
  This version seems to be the V1.1 KB-9 with added Hypertape and BLOCKMOVE routines at the end of the binary. With the alternative start addresses the hypertape routine can be moved to $0200 or $0300 and the SAVE command patched to the hypertape routine. Or with the standard start at $4065 hypertape can be skipped.
  All KB-9 internal addresses are the same.
• KB-9P
  Mentioned in the documentation of the versions distributed by Johnson Computer with ID #101, Binary not available.
  KB-9P is a stripped version of KB-9 fit for burning into a ROM. SIN-COS-ATN is not available.

My MSBasic for the KIM-1 cassette

Another MOS TECH BASIC for KIM-1, lower serial number

Thanks Gerben Voort