---
title: MITS ALTAIR 8800
categories:
- Computers
types:
- Professional Computer
origins:
- U.S.A.
years:
- '1975'
cpus:
- Intel 8080A
params:
  name: ALTAIR 8800
  image: /media/museum/photos/mits_altair-8800_2.jpg
  company: /companies/mits
  company_name: MITS
  specs:
  - label: NAME
    value: ALTAIR 8800
  - label: MANUFACTURER
    value: MITS
  - label: TYPE
    value: Professional Computer
  - label: ORIGIN
    value: U.S.A.
  - label: YEAR
    value: '1975'
  - label: KEYBOARD
    value: No keyboard, but switches on front panel.
  - label: CPU
    value: Intel 8080A (rarely 8080)
  - label: SPEED
    value: 2 MHz (each instruction takes 4 clock cycles)
  - label: RAM
    value: 256 bytes (you had to buy this memory board)
  - label: ROM
    value: None
  - label: TEXT MODES
    value: None (optional 64 x 12 card)
  - label: GRAPHIC MODES
    value: None
  - label: SIZE / WEIGHT
    value: Unknown
  - label: I/O PORTS
    value: Unknown
  - label: POWER SUPPLY
    value: Unknown
  - label: PRICE
    value: $595
  tabs:
  - photos
  - adverts
  - hardware
  - emulators
  - links
  - docs
  - videos
  forum_thread: 78
  photos:
  - title: LARGE VIEW
    subtitle: ''
    text: ''
    image: /media/museum/photos/altair_8800_system_s1.jpg
  - title: 'FRONT PANEL #1'
    subtitle: ''
    text: ''
    image: /media/museum/photos/altair_8800b_fpanel_1.jpg
  - title: 'FRONT PANEL #2'
    subtitle: ''
    text: ''
    image: /media/museum/photos/altair_8800b_fpanel_2.jpg
  - title: TOP VIEW
    subtitle: ''
    text: ''
    image: /media/museum/photos/altair_8800b_top_1.jpg
  - title: INSIDE
    subtitle: ''
    text: Note that the back plane didn't receive all of its S-100 connectors. Only the CPU board is inserted.
    image: /media/museum/photos/altair_8800b_inside_1.jpg
  - title: ALTAIR PERIPHERALS
    subtitle: ''
    text: Various peripherals including a paper tape reader and 8'' floppy drive units
    image: /media/museum/photos/altair_8800_peripherals_1.jpg
  - title: THE TARBELL CASSETTE INTERFACE
    subtitle: ''
    text: This interface can be used with IMSAI or ALTAIR. It transfers from 187 to 540 bytes / second
    image: /media/museum/photos/tarbell_k7.jpg
  - title: BILL GATES
    subtitle: ''
    text: Bill Gate giving a demonstration of its first BASIC interpreter, written for the Altair 8800.
    image: /media/museum/photos/altair_8800_billgates_1.jpg
  - title: PROGRAM EXAMPLE
    subtitle: ''
    text: |-
      An example of assembly program user could enter using sense switches.

      Thanks to **Mark Thompson**
    image: /media/museum/photos/altair_8800_progsample_1.jpg
  - title: PAPER TAPES
    subtitle: ''
    text: |-
      Original Altair paper tape programs. This Assembler package consisted of a **Monitor**, an **Editor**, an **Assembler** and a **Debugger**.

      Thanks to **Mark Thompson**
    image: /media/museum/photos/altair_8800_papertapes_1.jpg
  adverts:
  - title: FIRST ADVERT
    subtitle: ''
    text: 'This painting was the first and the best known MITS Altair advert. It was created by Kim Behm who has since become a well-known artist. At the first beginning of the personal computers era, this advert seems to be saying: In a near future, everybody around the world will have access to a personal computer.'
    image: /media/museum/pubs/altair_8800_pub_1.jpg
  - title: 'ADVERT #2'
    subtitle: ''
    text: Thanks to **Mark Thompson**
    image: /media/museum/pubs/altair_8800_franklinad_1.jpg
  - title: POPULAR ELECTRONICS
    subtitle: ''
    text: Cover and extracts of a 6 page article in the January 1975 issue of Popular Electronics
    image: /media/museum/pubs/altair_8800_popularelectronics_1.jpg
  - title: SHOW BAG
    subtitle: ''
    text: ''
    image: /media/museum/pubs/altair_8800_bag_1.jpg
  - title: 1976 PRICE LIST
    subtitle: ''
    text: |-
      Notice that the 16K static RAM expansion is more expensive than the computer itself.

      Thanks to **Mark Thompson**
    image: /media/museum/pubs/altair_8800_pricelist_1.jpg
  - title: 1976 XMAS CATALOG
    subtitle: ''
    text: Thanks to **Mark Thompson**
    image: /media/museum/pubs/altair_8800_xmascatalog_1.jpg
  - title: 'MITS BROCHURE #1'
    subtitle: ''
    text: Thanks to **Mark Thompson**
    image: /media/museum/pubs/altair_8800_brochure_1.jpg
  - title: 'MITS BROCHURE #2'
    subtitle: ''
    text: ''
    image: /media/museum/pubs/altair_8800_salebrochure_s1.jpg
  - title: ALTAIR 'MOBILE' COURSE
    subtitle: ''
    text: Thanks to **Mark Thompson**
    image: /media/museum/pubs/altair_8800_course_1.jpg
  - title: COMPUTER NOTES
    subtitle: ''
    text: |-
      This fanzine - one of the first of the microcomputers era - was published by the Altair User Group

      Thanks to **Mark Thompson**
    image: /media/museum/pubs/altair_8800_compnotes_1.jpg
  - title: ALTAIR CONVENTION
    subtitle: ''
    text: |-
      The first Altair Convention was here announced in the Computer Notes magazine.

      Thanks to **Mark Thompson**
    image: /media/museum/pubs/altair_8800_compnotes_2.jpg
  - title: BIT SHOPPER
    subtitle: ''
    text: Spring 1978 issues of Byte Shopper
    image: /media/museum/pubs/altair_8800_bitshopper_1.jpg
  - title: EARLY ADVERT (SEPTEMBER 1975)
    subtitle: ''
    text: from Creative Computing magazine
    image: /media/museum/pubs/mits_altair_pub-creative-compuetug%20sept1975.jpg
  - title: EARLY ADVERT (SEPTEMBER 1975)
    subtitle: ''
    text: from Creative Computing magazine
    image: /media/museum/pubs/mits_altair_pub-creative-computing-sept1975_2.jpg
  - title: EARLY ADVERT (NOVEMBER 1975)
    subtitle: ''
    text: from Creative Computing magazine
    image: /media/museum/pubs/mits_altair_pub-creative-computing-nov1975.jpg
  hardware:
  - title: FLOPPY DISK SYSTEM
    subtitle: ''
    text: |-
      Advert (March 1977) said:

      "The North Star Micro-Disk System uses the Shugart minifloppy disc drive. The controller is an S-100 compatible PC board with on-board PROM for bootstrap load. It can control up to three drives. With the PROM bootstrap, we provide our powerful extended Basic (10 Kb) with sequential and random disk file accessing.\
      Each 5.25'' diskette has 90k data byte capacity. Basic loads in less than 2 seconds.

      Micro-Disk system (kit) **$699**\
      Micro-Disk system (Assembled) **$799**\
      Additional drive **$425**\
      Diskette **$4.5**"
    image: /media/museum/hardware/altair_8800_fd_1.jpg
  - title: CPU CARD
    subtitle: ''
    text: ''
    image: /media/museum/hardware/altair_8800_card_cpu_1.jpg
  - title: 1 KB STATIC RAM
    subtitle: ''
    text: ''
    image: /media/museum/hardware/altair_8800_card_1kstatic_1.jpg
  - title: 4 KB DYNAMIC RAM
    subtitle: ''
    text: ''
    image: /media/museum/hardware/altair_8800_card_4kdram_1.jpg
  - title: SERIAL I/O CARD
    subtitle: ''
    text: ''
    image: /media/museum/hardware/altair_8800_card_serialio_1.jpg
  - title: TEST CARD
    subtitle: ''
    text: Tis card was used to test each contact of a S-100 connector
    image: /media/museum/hardware/altair_8800_testconnectorboard.jpg
  - title: US ADVERT (1977)
    subtitle: ''
    text: You could use these joysticks with the Altair or any S100 bus system. They connect to the Cromenco D+7/A I/O board and were meant to play the games available for the Cromenco TV Dazzler, the first video card for personal computer.
    image: /media/museum/hardware/cromenco-joysticks_pub_1-1977.jpg
  emulators:
  - title: SIMH
    url: http://simh.trailing-edge.com/
    platform: Windows
    text: Windows emulator for a lot of mini computers. Sources are available so you can compile them for your own platform.
  - title: Altair and IMSAI Emulators
    url: http://www.threedee.com/jcm/emu8080/index.html
    platform: Other platform
    text: A list of Altair / IMSAI emulators
  links:
  - title: Altair 8800 brochures
    url: http://altair.ftldesign.com/
    text: 1974 - 1976 Altair 8800 Brochures and Price Lists
  - title: 'Computers : from the past to present'
    url: http://www.eingang.org/Lecture/altair.html
    text: Altair page
  - title: The Virtual Altair Museum
    url: http://www.virtualaltair.com/
    text: Infos about MITS/Pertec Altair 8800/680b/MITS 300/Attache systems
  docs:
  - title: OPERATOR'S MANUAL
    url: http://www.1000bit.net/support/manuali/manuali.asp
    cover: /media/museum/docs/couvs/mits_altair8800_operator-manual.jpg
    text: |-
      [**OPERATOR'S MANUAL**](http://www.1000bit.net/support/manuali/manuali.asp)written by MITS

       compiled/archived by Robert Krten\
       type of document : PDF\
       size : 5,5 MB\
       source : [www.1000bit.net](http://www.1000bit.net)
  - title: ASSEMBLY MANUAL
    url: http://www.1000bit.net/support/manuali/manuali.asp
    cover: /media/museum/docs/couvs/mits_altair8800_assembly-manual.jpg
    text: |-
      [**ASSEMBLY MANUAL**](http://www.1000bit.net/support/manuali/manuali.asp)written by MITS

       compiled/archived by Robert Krten\
       type of document : PDF\
       size : 7 MB\
       source : [www.1000bit.net](http://www.1000bit.net)
  - title: THEORY OF OPERATIONS - MANUAL & SCHEMATICS
    url: http://www.1000bit.net/support/manuali/manuali.asp
    cover: /media/museum/docs/couvs/mits_altair8800_theory-of-operation.jpg
    text: |-
      [**THEORY OF OPERATIONS - MANUAL & SCHEMATICS**](http://www.1000bit.net/support/manuali/manuali.asp)written by MITS

       compiled/archived by Robert Krten\
       type of document : PDF\
       size : 387 KB\
       source : [www.1000bit.net](http://www.1000bit.net)
  - title: VARIOUS SCHEMATICS
    url: http://www.1000bit.net/support/manuali/manuali.asp
    cover: /media/museum/docs/couvs/mits_altair8800_schematics.jpg
    text: |-
      [**VARIOUS SCHEMATICS**](http://www.1000bit.net/support/manuali/manuali.asp)written by MITS

       compiled/archived by Robert Krten\
       type of document : PDF\
       size : 936 KB\
       source : [www.1000bit.net](http://www.1000bit.net)
  videos:
  - title: MITS Altair 8800 demonstration
    url: https://www.youtube.com/watch?v=vAhp_LzvSWk
    text: 'Length: 8 min 45 s'
  - title: How the Altair 8800 started the PC revolution
    url: https://www.youtube.com/watch?v=WVwfDA4watU
    text: 'Length: 7 min 40 s'
  - title: ALTAIR 8800 -The Computer that started Microsoft
    url: https://www.youtube.com/watch?v=vD4xHCW9YCQ
    text: 'Length: 3 min 14 s'
  related:
  - /museum/imsai-8080
  oc_id: 62
  source:
    url: https://web.archive.org/web/20230413211213/http://www.old-computers.com/museum/computer.asp?c=62
    date: '2023-04-13'
---

This computer was one of the first "home" computers ever made, it was sold as a kit, but for additional money, you could buy one fully assembled.

It had no keyboard, the "program" had to be entered with the switches located on the front panel of the "computer", and as it didn't have video output (yet), the result was displayed via LEDs.

Another computer which had almost the same characteristics was launched by IMSAI and was called [IMSAI 8080](/museum/imsai-8080/) (see both in the "Emulators" section).

The ALTAIR 8800 had one input port, also called the "Sense Switches" (I/O address 255) which was the left hand 8 address switches. Address 255 was also used on the IMSAI. The IMSAI front panel differed from the Altair in that you could also output to port 255 to a displayed LED buffer above the sense switches - a feature the Altair did not have (it only had input). The Altair sense switch were used during boot into Altair DOS to specify the terminal port to the DOS.

MITS made several peripherals and cards for this computer, namely, a video card, a serial card to connect a terminal, a RAM expansion card and a 8" floppy drive that used hard sectored floppies and stored 300 KB.

Several models were launched, they had the same characteristics except the CPU (8080 and later 8080A).

Believe it or not, the name "Altair" comes from Star Trek! The young daughter of the 'Popular Electronics' magazine editor gave it the name of the destination planet of the Enterprise from the episode she was watching.