KIM-1 Revisions, what changed?

I know of seven KIM-1 revisions, labeled Rev A-G and the first one unlabeled. Rev C is unknown!

What changed between these revisions?

Not much. The PCB underwent several changes around the logo area, from KIM-1 MOS to Commodore C-MOS. That happened from Rev A to Rev D, indicating the takeover by Commodore of MOS Technology. And some small numbers/artefacts etched in various Revs.

Some have serial numbers, the first ones on the back on the right, later had stamped/written numbers like PAxxx (Palo Alto) and SCxxx (Santa Clara) of Commodore production facilities

There was a real change in the PCB from Rev A to B.

Rev A

Rev B

The User Manual went from version 15 (January 1976) to 15A (March 1976) to 15B (August 1976) without significant changes, mostly typing errors and the change of keyboard from Rev B to Rev D.
The keyboard changed from rev B to Rev D. The SST switch moved to the other side, the first Rev keyboards were not very reliable.

Rev B

Rev D

What did not change?

The 6530 – 002 and -003 were from many different dates between 1976 and 1980. The functionality stayed the same, no software changes are known. It seems the same mask was used to produce another batch due to the demand for KIM-1s. On Rev F and G I have seen older 6530s (ceramic ones) from much earlies dates, old stock being used?

The large Circuit Diagram poster stayed the same for all revisions.

Parts used

The parts used in all these revisions changed from as much as possible made by MOS Technology (6102) to industry standard compatible types (2102). E.g the RAM ICs were all third party in later revisions.
The capacitors, mostly yellow tube types, also came in various colors and sources between revisions.

Except for Rev G no IC sockets were used.

KIM-1, were IC sockets used?

Before I saw the last revision, Rev G, I had never seen an original KIM-1 with IC sockets. All ICs were soldered right into the PCB.

Now I have a KIM-1 Rev G and a photo by Dick Dral of his KIM-1 Rev G with white IC sockets.


So the last iteration of the KIM-1 did have IC sockets.

Not only did Rev G come with sockets, they used not only white sockets, black ones too (Thanks Santo Nucifora).

My KIM-1 collection

In 2024/2025 I completed my KIM-1 collection with one or two from every Revision, from first edition to Rev G, nine in total.

Versions of the KIM-1 User Manual

I have so far found 5 versions of the KIM-1 User Manual.

First Edition January 1976
Second Edition March 1976
Second Edition August 1976
Rockwell branded version 1977.
German version 1977
Only small updates, some errors, and the change of keyboard with SST switch right to left.

All available here: KIM-1 manuals and MOS Technology documents – Retro Computing

The Rockwell KIM-1

Once in a while I hear a myth on the internet about Rockwell manufactured the KIM-1. That myth needs to be debunked.

Rockwell did sell KIM-1s as an OEM product around 1977. They bought the KIM-1 PCB, made in a Commodore factory and put a sticker on the right corner, covering the Commodore MOS logo and text, as you can see in the image below.

The documentation such as KIM-1 User Manual and the Circuit Poster were given a new front and back, the contents of the User Manual were 99% coming verbatim from MOS Technology/Commodore. The Programming and Hardware Manual were later (and better) versions of the MOS Technology documents, no trace of the 6501!

I can proof this, in 1978 I bought a KIM-1 from a Dutch distributor Famatra and still have it. It was a Rockwell package. Here you see photos of my Rockwell KIM-1 package labeled as Rockwell but it really is a Commodore MOS Technology product rebranded. It did not take long before Rockwell started to sell the AIM 65 as replacement and I never saw advertisements not a Databook with a Rockwell KIM-1 in it.

The Rockwell KIM-1 User Manual is scanned by me and available on the KIM-1 and MOS Technology manuals page, as are (later versions of) the Rockwell Hardware and Programming manual. I might scan these Rev 0 versions one day also.

See the page of me and my KIM-1 for my first KIM-1 and its history.

You can see the text Commodore and MOS logo shining trough underneath the Rockwell sticker. And the number SC1276 gives away it was manufactured in the Santa Clara Commdore factory.

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KIM-1 PCB Edge connectors

The KIM-1 needs 2 edge connectors.

The specifications are: card edge; PIN: 44; 3.96mm

When you search for those, the cheap ones pop up, Chinese made, look good. But they are no good, when you slide them one you need a lot of force, some even use a hammer!
The PCB is too thick for these connectors, you damage the edge fingers and can not change once connected.
DO NOT USE THEM for a KIM-1!

I had some luck, years ago I bough a lot, cable type (solder eyelets) from Conrad and they are perfect for the KIM-1.

307-044-500-202 Standard Card Edge Connectors 44P SOLDER EYELETS 5.08mm ROW SPACE, for sliding on a PCB edge connector.
307-044-520-202 Standard Card Edge Connectors 44P Card Edge PC Tail, for a motherboard

EDAC 307 357 Series Card Edge Connectors English Ordering Guide

307-044-520-202 – EDAC Card Edge Connector

307-044-500-202 – EDAC Card Edge Connector

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KIM-1 connectors: beware the Chinese cheap variants!

The KIM-1 needs 2 edge connectors.

The specifications are: card edge; PIN: 44; 3.96mm

When you search for those, the cheap ones pop up, Chinese made, look good. But they are no good, when you slide them one you need a lot of force, some even use a hammer!
The PCB is too thick for these connectors, you damage the edge fingers and can not change once connected.
DO NOT USE THEM for a KIM-1!

I had some luck, years ago I bough a lot, cable type (solder eyelets) from Conrad and they are perfect for the KIM-1.

307-044-500-202 Standard Card Edge Connectors 44P SOLDER EYELETS 5.08mm ROW SPACE, for sliding on a PCB edge connector.
307-044-520-202 Standard Card Edge Connectors 44P Card Edge PC Tail, for a motherboard

EDAC 307 357 Series Card Edge Connectors English Ordering Guide

307-044-520-202 – EDAC Card Edge Connector

307-044-500-202 – EDAC Card Edge Connector

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Dungeons And Dragons Dice Simulator For The KIM-1

In Compute! Issue 13, June 1981, a small program is published. It runs on an unexpanded KIM-1, showing a random number as used by the dices in a board game Dungeons And Dragons.

Dungeons And Dragons Dice Simulator For The KIM-1

The program is typed in by me, using TASM32 as assembler. And tested on the KIM-1 Simulator.

Here the archive with source, article and binaries.

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MICRO

MICRO The 6502 Journal

Published by Robert M. Tripp, The Computerist
Published from 1977 tot 1983. The first years many KIM-1/SYM-1/AIM-65 articles, slowly faded to Apple Atari etc in later years, and ended in 1984.
The whole archive is here.

Best of MICRO 1

Best of MICRO 1, 1978

Best of MICRO 2

Best of MICRO 2 1979

Best of MICRO 3

Best of MICRO 3, AIM 65 SYM-1 KIM-1 part June 1979 May 1980

KIM-1/6502 User Notes

KIM-1/6502 User Notes is a publication about the KIM-1, slowly evolving to other 6502 systems like SYM-1 and AIM 65.
Editor was the famous Eric Rehnke. After issue 17 it merged with Compute II.
KIM-1 / 6502 USER NOTES INDEX BY SUBJECT VOLUME 1(Issues 1 till 6)
APPLICATIONS FOR KIM             GENERAL INFORMATION
Application suggestions   1        Correction To Memory Map -------- 2
Calculator--Interface     4        Defective 6502 chips------------- 3
Interface     6        Discussion of Memory Allocation - 5
--T.I.5050      5        DISPLAY (on board)
Chess Clock Program       4           red filter for-----------------5
CONTROLLING                      Use of------------------------------1,5
--- Function Generator   1        EXPANSION OF SYSTEM
--- Light Intensity      4           KIMSI--------------------------4
--- Motor Speed          4           MEMORY
--- Touch tone encoder   1            Adding memory to KIM-1--------5
Degree Dispatch Computer  5            Diagnostic------------------- 2,5
Frequency Counter         3            Expansion---------------------4,3
OSI Memory-------------------------3
GAMES                             Using SD Sales 4K RAM Board        3
Bagels----------------- 5       Hardware tips
Battleship--------------6          Packaging KIM-1 --------------- 6,3
Horserace-------------- 3          Power Supply for KIM ---------- 4
Hunt the Wampus-------- 2          Red Filter for Display----------5
Jotto------------------ 5       INTERVAL TIMERS :
Kimmaze---------------- 4          The Other Timer-----------------2
Microchess------------- 3          and cassette                    2
Mastermind------------- 5          Use Of--------------------------5,5
Moon Lander-----------1,3       MIKIM------------------------------5
HEDEX Program             1       OPERATION TIPS
MATH TEST Program         4          Using SST  ---------------------2
Mini-l Loran-c            6          Using ST   to start programs----4
MUSIC:KlugeHarp     3,2,6,6       Page 1 Programming Problems--------6
Real Time Clock        4, 5       Packaging your KIM-1---------------3
Square wave generator     5       Power Supply-----------------------4
Stopwatch Program         2       Presetting 00F1, 00F2              4
Telephone Dialer        4,4         System Architecture              3
Packaging your KIM-1---------------3
CASSETTE PROBLEMS/SUGGESTIONS     Presetting 00F1, 00F2              4
Certification of tape     6       System Architecture                3
Copying Cassette tape     3       TABLES for KIM-1
Fast tape problems        6          Interval Timer Table------------3
Hypertape               2,6           Relative Branch table----------2
Interval timer/cassette   1          OP Code table-------------------4
Notes on cassette         6       Techniques
PLL set program           5          Mnemonic Improvement------------41
PROBLEMS with Cassette    3                   BIT Data---------------41
Software control of tape         Top Down Programming                4
reading                 4      Modifications/ IMPROVEMENTS
Speed up                  4         Crystal Stabilization------------5
Supertape                 2         Factory Mods. -------------------4
Supertape improvement     4         6502 Register Monitor Apparatus  4
Tape Certifying           6         74Ls145 ------------------------ 3,4
Tape Dupe                 4      6502 Microprocessor Board-----------6
Using Cassette            6         POWER ON RESET CIRCUIT           3
Varification of Data      4         NOTES FROM THE FACTORY           5
Vutape                    2      
INDEX Issue 13
SOFTWARE FEATURE                                                         1
KIM Hexpawn (your KIM can learn to win)        Robert C. Leedon
6502 OP CODES (arranged logically for easy look up) Jim Butterfield      6
CASSETTE INTERFACE STUFF                                                 7
Tape Verify II                                 Dr. Barry Tepperman
Radio Tape Feedback                            Daniel Gardner
Reliability Hint                               John Watney
Help Relay Package Fixit                       Mike Firth
Tape File Recovery Routine                     Loel Swank
KIM Software On Cassette
LANGUAGE LAB                                                             10
Focal
I/O Mods                                  Editor
Functions                                 Editor
Basic
I/O Mods                                  Marvin De Jong
A Basic Question                          Editor
Basic Timing Comments                     F. E. Kempisty
KIM Basic Hint                            Micro-Z Company
Basic Renumber Program                    Harvey Herman
Tiny Basic
Two Tiny Basic Mods                       Michael Day
Ramblings About T.B.                      Lew Edwards
Forth
Forth Comments Example                   John P. Oliver
Assemblers
Two Pass Patch To Aresco Assembler        John Eaton
Mods To MSS Assembler                     Richard M. Bender
DESIGN CORNER                                                           16
A 6522 I/O Board
KIM-4 BUS PINOUT                                                         18
VIDEO  GRAPHICS                                                          19
Video Displays                                 Editor
Comments On Visible Memory                     Lew Edwards
TVT-6 Adventure                                Dennis Chaput
TVT-6 RAM Expansion                            Michael Allen
Polymorphics Video Board Mods                  Editor
DEBUG                                                                    21
Slow Stepper IV                                Lew Edwards
LETTERS  COMMENTS                                                        22
SOFTWARE LIBRARY
Multi-Mode Adder                               Jim Butterfield
Pseudo-Random Number Generator                 H. T. Gordon
ASCII Dump Program                             Jim Zuber
Keyboard Debounce Routine                      Thomas J. Rubens
Sound Effects Program                          Bob Carlson
Melodies For The Music Box                     Douglas Lyon
'Do Loops'; For KIM                            Dave Skillman
INTERFACE                                                                26
Camera Speed Tester                            Mike Firth
Low-Cost Modem Possibility                     Editor
RPN Calculator Chip Interface                  Editor
Power-On Reset                                 George Hawkins
The Outside World Connection                   Editor
More On The Opto-Isolator                      Dwight Egbert
NEW PRODUCTS                                                             28
Video Driver Package
Price Decrease On Jolt Boards
A 8080 Simulator For The 6502
Eprom Programmer
INDEX Issue 14
INDEX
EDITORIAL
SOFTWARE FEATURES                                                         1
KIM BANNER PROGRAM                             JIM ZUBER
6KIM DISASSEMBLER
CHECK-OUT                                      ROBERT LARRABEE
LANGUAGE LAB                                                             12
BASIC
MOD AND PROGRAMMING HINT                  HEINZ JOACHIM SCHILLING
OUTPUT PAGING MOD                         DICK GRABOWSKY
RENUMBER ADDENDUM AND SOME MODS           HARVEY HERMAN
AUTOMATIC LINE NUMBER ENTRY MOD           SEAN MCKENNA
A NEW COMMAND                             DICK GRABOWSKY
PRODUCT ANNOUNCEMENT
'USR' FUNCTION INFO                       C. KINGSTON
FOCAL
TINY BASIC
FORTH
XPL0
SYM SECTION                                                              18
ACCESSING THE SYM DISPLAYS                     A.M. MACKAY
SYM NOTES & KIM-4 COMPATIBILITY                C. KINGSTON
WUMPUS   MUSIC BOX MODS                        JIM ADAMS
AIM SECTION                                                              19
MANUAL CORRECTIONS                             JODY NELIS
VIDEO   TVT-6                                                            23
POLYMORPHICS VIDEO/KIM INTERFACE               MIKE FIRTH
TVT-6 NOTES & RAM EXPANSION                    MILAN MERHAR
INTERFACING TO THE TVT II                      JOHN M. RENSBERGER
CASSETTE STUFF                                                           25
MAKE A SHORT CASSETTE                          TED BEACH
CASSETTE DIRECTORY PRINTOUT PROGRAM            CHRIS MCCORMACK
ANNOUNCEMENTS  REVIEWS
KIM-1 User Notes Volume 0, July 1976
KIM-1/6502 User Notes Volume 1, September 1976
KIM-1/6502 User Notes Volume 1, other version
KIM-1/6502 User Notes Volume 2, November 1976
KIM-1/6502 User Notes Volume 2, other version
KIM-1/6502 User Notes Volume 3, Januari 1977
KIM-1/6502 User Notes Volume 3, other version
KIM-1/6502 User Notes Volume 4, March 1977
KIM-1/6502 User Notes Volume 4, other version
KIM-1/6502 User Notes Volume 5 May 1977
KIM-1/6502 User Notes Volume 5 May 1977
KIM-1/6502 User Notes Volume 6, July 1977
KIM-1/6502 User Notes Volume 6, other version
KIM-1/6502 User Notes Volume 7/8, September November 1977
KIM-1/6502 User Notes Volume 7/8, Other version
KIM-1/6502 User Notes Volume 9/10 January March 1978
KIM-1/6502 User Notes Volume 9/10 other version
KIM-1/6502 User Notes Volume 11 May 78
KIM-1/6502 User Notes Volume 11 other version
KIM-1/6502 User Notes Volume 12
KIM-1/6502 User Notes Volume 12 other version
6502 User Notes Volume 13
6502 User Notes Volume 13. incomplete other version
6502 User Notes Volume 14
6502 User Notes Volume 15
6502 User Notes Volume 16
6502 User Notes Volume 17