website/content/museum/mos-technology-kim-1.md

---
title: MOS TECHNOLOGY KIM 1
categories:
- Computers
types:
- Home Computer
origins:
- U.S.A.
years:
- '1975'
cpus:
- '6502'
params:
  name: KIM 1
  image: /media/museum/photos/mos_kim1.jpg
  company: /companies/mos-technology
  company_name: MOS TECHNOLOGY
  specs:
  - label: NAME
    value: KIM 1
  - label: MANUFACTURER
    value: MOS Technology
  - label: TYPE
    value: Home Computer
  - label: ORIGIN
    value: U.S.A.
  - label: YEAR
    value: '1975'
  - label: KEYBOARD
    value: Hexadecimal keyboard, calculator type
  - label: CPU
    value: '6502'
  - label: SPEED
    value: 1 MHz
  - label: RAM
    value: 1152 bytes
  - label: ROM
    value: 2 KB (assembler)
  - label: TEXT MODES
    value: 6 digits LED screen
  - label: GRAPHIC MODES
    value: None
  - label: COLORS
    value: 'No'
  - label: SOUND
    value: Various square wave frequencies could be produced by software
  - label: SIZE / WEIGHT
    value: Unknown
  - label: I/O PORTS
    value: tape interface, bus expansion, serial (to connect to a terminal)
  - label: POWER SUPPLY
    value: 5V / 1.2A and 12V / 100mA. The 12V was only needed for the serial function
  - label: PERIPHERALS
    value: Unknown
  - label: PRICE
    value: $250 (USA, 1975)
  tabs:
  - photos
  - adverts
  - hardware
  - connectors
  - emulators
  - links
  - docs
  photos:
  - title: COMMODORE VERSION
    subtitle: ''
    text: |-
      When Commodore bought MOS Technology in 1976, KIM 1 boards were sold with the 'Commodore - MOS' label

      Thanks to **Richard de Keijzer**
    image: /media/museum/photos/mostech_kim1_commodore_2.jpg
  - title: LABEL CLOSE-UP
    subtitle: ''
    text: Thanks to **Richard de Keijzer**
    image: /media/museum/photos/mostech_kim1_label_1.jpg
  - title: DOUBLE SIDE CIRCUIT
    subtitle: ''
    text: Picture showing all the tracks of the double side circuit.
    image: /media/museum/photos/mostech_kim1_doubleside_1.jpg
  - title: KIM-1 SCHEMA
    subtitle: ''
    text: ''
    image: /media/museum/photos/mostech_kim1_schematics_1.jpg
  - title: KIM-1 MANUALS
    subtitle: ''
    text: These are the original programing, hardware and KIM-1 user manuals, dated 1976.
    image: /media/museum/photos/mos_kim1_manuals_1.jpg
  - title: 'KIM CALCULATOR #1'
    subtitle: ''
    text: |-
      This antique calculator is not really a calculator, but an ideal case for a KIM-1 board equiped with a full stroke keyboard and a nice display ;-)\
      See the next picture for further details.
    image: /media/museum/photos/mostech_kim1_calculator_2.jpg
  - title: 'KIM CALCULATOR #2'
    subtitle: ''
    text: Inside the KIM calculator.
    image: /media/museum/photos/mostech_kim1_calculator_1.jpg
  adverts:
  - title: 1976 ADVERT
    subtitle: ''
    text: ''
    image: null
  hardware:
  - title: RAM BOARD
    subtitle: ''
    text: ''
    image: /media/museum/hardware/mostech_kim1_ramboard_1.jpg
  - title: PAPER TAPE READER
    subtitle: ''
    text: This paper tape reader manufactured by the Teleterminal Corporation and called the Fly Reader could be connected to the Kim 1 board. It could read a paper tape at 300 characters per second. The advantage of the paper tape reader was it could read a little part of a program, even a single character. Unfortunately, it wasn't a puncher and the user had to acquire already punched tapes.
    image: /media/museum/hardware/mostech_kim1_papertape_1.jpg
  connectors:
  - title: CARDEDGE CONNECTORS
    subtitle: ''
    text: |-
      Basically it's not easy to get or find the specifications of the cardedge connectors you need for the "A" and "E" slots of a KIM-1.

      In the manual "KIM-1 Hints" you can find the folowing text:\
      4\. WHERE CAN I GETMORE 44-PIN EDGECONNECTORS FOR KIM?\
      The connector is a standard part - you can order a Vector No. R644 from most electronic supply houses.\
      The connector is also carried by most Radio Shack stores as Part No.276-548.

      Unfortunately Vector No. 644 is not easy to find. Radio Shack Stores are unknown with Part No.276-548. So I tried to find the Specifications nowdays, and some Part No. for Europe. Outside Europe, you can always go to your local dealer with the specifications.

      Specifications:\
      Cardedge Connector 44 (2x22) 3,96MM or 0,156"\
      Part No.\
      Conrad Electronics: 74 07 05-44\
      Local Dealer: 05.34.2.22B (Print Solder) 05.34.2.22C (Hand Solder)

      Thanks to **Richard de Keijzer** from the Netherlands for these info.
    image: /media/museum/connectors/mostech_kim1_connector_1.jpg
  emulators:
  - title: Soft6502
    url: http://www.crbond.com/soft6502.htm
    platform: Windows
    text: KIM 1 simulator and 6502 programming trainer
  - title: MESS (Multi Emulator Super System)
    url: http://www.mess.org
    platform: Other platform
    text: MESS emulates the KIM-1 for many platforms
  - title: The Incredible KIMplement
    url: http://www.floodgap.com/retrobits/kim-1/
    platform: Other platform
    text: KIM-1 emulator for the Commdore 64 !!!
  links:
  - title: Everything you want to know about the KIM 1 is here !
    url: http://ftp.funet.fi/pub/cbm/schematics/kim-1/index-t.html
    text: ''
  - title: KIM-1 page
    url: http://home.hccnet.nl/g.baltissen/kim.htm
    text: Nice description with original docs, ROM sources and more
  - title: Online manuals
    url: http://www.ping.be/kim-1__6502/
    text: Online user manual, hardware manual and programming manual!
  - title: The KIM-1 Enthusiasts Page
    url: http://www.kim-1.com/
    text: Nice site with photo gallery, documentations and more
  docs:
  - title: KIM-1 USER'S GUIDE
    url: http://www.commodore.ca/manuals/kim1/kim1_users_guide.txt
    cover: /media/museum/docs/couvs/vide.gif
    text: |-
      [**KIM-1 USER'S GUIDE**](http://www.commodore.ca/manuals/kim1/kim1_users_guide.txt)written by MOS Technology

       compiled/archived by www.commodore.ca\
       type of document : TXT\
       source : [www.commodore.ca](http://www.commodore.ca)
  - title: KIM-1 HARDWARE MANUAL
    url: http://www.commodore.ca/manuals/kim1/kim1_hardware.txt
    cover: /media/museum/docs/couvs/vide.gif
    text: |-
      [**KIM-1 HARDWARE MANUAL**](http://www.commodore.ca/manuals/kim1/kim1_hardware.txt)written by MOS Technology

       compiled/archived by www.commodore.ca\
       type of document : TXT\
       source : [www.commodore.ca](http://www.commodore.ca)
  - title: KIM-1 HINTS
    url: http://www.commodore.ca/manuals/kim1/kim1_hints.txt
    cover: /media/museum/docs/couvs/vide.gif
    text: |-
      [**KIM-1 HINTS**](http://www.commodore.ca/manuals/kim1/kim1_hints.txt)written by MOS Technology

       compiled/archived by www.commodore.ca\
       type of document : TXT\
       source : [www.commodore.ca](http://www.commodore.ca)
  - title: KIM-1 MONITOR SOURCE CODE
    url: http://www.commodore.ca/manuals/kim1/kim1_mon.txt
    cover: /media/museum/docs/couvs/vide.gif
    text: |-
      [**KIM-1 MONITOR SOURCE CODE**](http://www.commodore.ca/manuals/kim1/kim1_mon.txt)written by MOS Technology

       compiled/archived by www.commodore.ca\
       type of document : TXT\
       source : [www.commodore.ca](http://www.commodore.ca)
  comments:
  - author: Jeff Nay (USA)
    date: Thursday 24th February 2022
    text: Need help with book
  - author: Eric Andresen (United States)
    date: Tuesday 14th December 2021
    text: I recently built a Kim Uno which while it is not a Kim-1 provides a very nice emulated environment to play in and it can be build for about $18 in parts and the whole project is open source. Has anyone used this? I would like to enter some programs into $0400 but found that is where the ROMs usually were mapped. My unit will not allow me to write there, but I had read posts that you should be able to hold Rst for 1 second and that allows you to write to the non-volatile area of the Uno. Has anyone else walked this path? On the Strugglebus.
  - author: Jeff Nay (USA)
    date: Sunday 31st October 2021
    text: Hello Hams, Love your site, although it is hard for me to get through to you as you only provide Twitter and FB contact info. Your last post here, mentions something Unopened with manuals. What are you referring to? I do have a youtube site, that you might like. https://www.youtube.com/channel/UCbBQsLXk9W7oM7Pz5lZgHOg
  - author: Hans Otten (Netherlands)
    date: Wednesday 27th October 2021
    text: Unopened, new, with manuals worth quite a lot. At least $1000 depending on what Rev and IC''s used.
  - author: Chris Banda (Las Vegas, Nevada)
    date: Saturday 22nd August 2020
    text: 'I met Steve Wazniak and Jobs at the 1975 MOS Technology Convention in San Francisco. The next business day afterwards, I bought two Kim-1 boards. One I used at work and the other sat in its box until today. I never even applied power to it and bought it with the plug in socket chip option. Does anyone know what this board is worth on today''''s market? Thanks: Chris 323-218-1435, chris_51_m_ca@yahoo.com'
  - author: Bob Leedom (Maryland, USA)
    date: Tuesday 7th January 2020
    text: |-
      Tuesday, 7 Jan 2020\
      On the first page of this site''s KIM-1 section, I mention my hand-assembled KIM-Venture program, which runs on a bare KIM-1. I''d like to find a good place to post the user manual, source code, and cavern map for this "tiny Adventure" game. Or I''ll send it to anyone who asks! Write me at BOBkimLEEDOM at hotmail.com, but first remove the 3-character computer name from the address (added here to confound the spambots).
  - author: Tim Bennett
    date: Sunday 15th July 2012
    text: I incorporated a KIM-1 into USPTO patent $ 4,281,579 - issued in yr 1981. Demonstrated working prototype to US piano mfgs (who didn''t get it) but sold rights Yamaha who sold millions. Still have KIM-1 but will be listing on e-bay this week - Thursday 7/19/2012 . Will be interesting to see what it brings.
  - author: David Honig (USA)
    date: Friday 6th June 2008
    text: |-
      In the early 80s at age 16 I attended a science camp at RPI, and my project was to program a KIM-1 to use Newton's method to find the resonance of a rotating wheel. It was a lecture demo for a physics prof.

      I wrote machine code and hand assembled it, then punched it in. After a while you could read the machine code.
  - author: Rob urton (Olmsted Falls, Ohio)
    date: Sunday 4th February 2007
    text: Fond memories of these as I used them in my first real engineering job. Around 1978 we built a motion control system for animation cameras. It used stepping motor control hardware based on 6522s that I designed. The system was used to create motion graphics for TV spots mostly. I still have one with a KIM-3 4K RAM expansion card.
  - author: David Masson (STL)
    date: Sunday 22nd January 2006
    text: Does any one have a part list and a schematics for this? If you do please email me at david@massonfamily.com
  - author: Dennis German ( )
    date: Friday 20th February 2004
    text: By adding a 300baud Texas Instruments terminal and a modem to edit, assemble and download a program the KIM could CONTROL and monitor an N gauge train layout. The KIM interpreted a routing language including commands like T5C ( set Turnout 5 Curved). It's expansion capability was only unlimited by your imagination.
  - author: ytf (Cupertino, CA)
    date: Friday 16th January 2004
    text: |-
      Chris Baker:

      The KIM-1 was the first *stand-alone* single board computer, and the first one using the 6502. I believe the Apple I didn't ship until well after the KIM-1 had shipped. But in any event, the Apple-1 didn't have a "diskey" (display+keyboard), so I think the KIM-1 deserves pride of place.
  - author: Philip Wasson (Torrance, CA)
    date: Monday 29th December 2003
    text: Thank you Peter for Microchess! I loved it. I'm still amazed you wrote a chess program in 1k. I wrote a debug monitor that had a "video display". It used 2 analog ramp-up, ramp-down circuits that connected to the x-y inputs of my oscilloscope and displayed all the registers on the screen. I added a Selectric printer, keyboard, and 8k RAM.
  - author: Robert Lore (Sydney, Australia)
    date: Sunday 15th June 2003
    text: I rember this little beauty. Wonderful. Looking at the schematic shows a lot of stuff to make the tape work - all thos bits to the left of the keypad. Then I saw the Apple II book at the just opened ComputerLand shop. Steve Jobs replaced all this circuitry with one op-amp and a D-latch. I immediately wire-wrapped up this onto a S-100 bus prototype board. Copied the Apple II monitor ROM from the book (typed hex codes into DEC PDP8 - wrote paper tape - burned EPROM).... Plugged into the wirewrapped motherboard and bingo it fired up first go (never to be repeated). Even the cassette tape ran at double speed !
  - author: TheP (CA)
    date: Saturday 8th February 2003
    text: |-
      I have a KIM-1 that is missing a key on the keypad.\
      Is it possible to purchase a replacement keypad somewhere?
  - author: Harry Joel (Texas)
    date: Monday 13rd January 2003
    text: It was not easy, but circumstances led me to part with my beloved KIM-1. It was the machine that prompted me to pursue a career as programmer for the years to come after 1977, I auctioned it on eBay and the page got over 300 hits, meaning the spirit of the KIM-1 lives on. The final bid was a lot more than what I paid for it in 1977, It has found a new home.
  - author: Peter Jennings (Cyberspace)
    date: Thursday 10th October 2002
    text: |-
      My Kim-1 may have been the most expanded Kim around in 1978. I had the MOS Technology expansion board with 4K of RAM. I also designed a floppy disk interface to an 8 inch floppy disk and wrote a small DOS and development system based on Micro-ADE (Assembler Disassembler Editor).

      I just fired up my Kim, and it still works. Unfortunately, the only tape I had of Microchess broke when I tried to play it. Not sure if I will type it all in.

      My Kim-1 will be on display at the [Vintage Computer Festival](http://www.vintage.org), Oct 26-27. See you there.
  - author: Dennis Brown (Youngsville, NC)
    date: Monday 12th August 2002
    text: I built a wire-wrap 4K memory expansion card for my Kim-1. Then I built an interface to drive an IBM 1052 keyboardless Selectric printer. I also wrote driver software to make the printer operate... I often used a Teletype with papertape reader/punch and since the teletype only had an RS-232 serial interface, had to use an opto-iosolated coupler to connect to the Kim.
  - author: Peter (Earth)
    date: Wednesday 20th March 2002
    text: |-
      Microchess ran on the Kim-1. That was chess in 1K of RAM. Microchess on the Kim-1 was the first commercially successful game program for a home computer, first sold in 1976. It went on to sell more than a million copies\
      on the Apple \]\[ and TRS-80.
  - author: Bob Leedom (Glenwood, MD)
    date: Wednesday 20th March 2002
    text: Has anyone gotten a KIM-1 emulator to work? I've tried some of the links (MESS, e.g) with no luck. Key problem of course, is getting the ROM binary...
  - author: Chris Baker (Overland Park, KS)
    date: Friday 1st March 2002
    text: |-
      I have a question that I can not find an answer to on the web.\
      Is this the first publicly available computer to feature the 6502, or even perhaps the first ever to feature a 6502?
  oc_id: 149
  source:
    url: https://web.archive.org/web/20230608152603/http://www.old-computers.com/museum/computer.asp?c=149
    date: '2023-06-08'
---

This prehistoric computer has no "real" keyboard and no video output, program are entered by the small hexadecimal keyboard (located in the lower right part of the picture) and results are displayed on the small LED "screen" (it can display only 6 digits). It has a simple monitor that allows one to examine & modify memory, load and save paper tape, load and save cassette tape, run and debug programs through a 'single step' mode. The monitor works with the built in keypad and LEDs, or a terminal like the Teletype ASR33.

It is possible to connect the KIM to a terminal via a dedicated serial port.

Soon after release, Commodore Business Machines would buy out MOS Technologies and distribute the KIM-1 with a Commodore name on it.

**Bob Leedom** reports :\
The KIM-1 had "no video output", you say? And the "small LED screen...can only display 6 digits"?\
Not quite. The software could address each segment of the 7-segment displays in the "LED screen". As a result, tremendous ingenuity was unleashed by the KIM-1 User's Group, and the display was used for many clever things.\
The editors published my version of the artificial intelligence board game (in which the computer learns which moves lose, and never makes those moves again, until it's eventually unbeatable), my baseball game (two-player or you vs computer, six kinds of pitches possible, scoreboard, men-on-base display, lots more), and my semi-successful commercial entry called KIM-venture (a tiny version of Adventure, with XYZZY-type secret word, monsters, treasures, 26 rooms, and more).\
It was an amazing little computer. Mine still works!