---
title: Cromemco Z-1
categories:
- Computers
types:
- Professional Computer
origins:
- U.S.A.
years:
- '1976'
cpus:
- Z-80
params:
  name: Z-1
  company: /companies/cromemco
  company_name: Cromemco
  specs:
  - label: NAME
    value: Z-1
  - label: MANUFACTURER
    value: Cromemco
  - label: TYPE
    value: Professional Computer
  - label: ORIGIN
    value: U.S.A.
  - label: YEAR
    value: '1976'
  - label: BUILT IN LANGUAGE
    value: Basic Interpreter
  - label: CPU
    value: Z-80
  - label: SPEED
    value: 2 or 4 Mhz.
  - label: RAM
    value: 8 Kb. Static RAM (2 x 4 Kb. cards)
  - label: ROM
    value: 8 Kb.
  - label: TEXT MODES
    value: 25 lines x 80 char. with a RS-232 terminal
  - label: I/O PORTS
    value: 1 x Serial RS-232
  - label: POWER SUPPLY
    value: 28 amperes internal power supply
  - label: PERIPHERALS
    value: 22 card slots
  - label: PRICE
    value: 'Basic version : $2495'
  tabs:
  - adverts
  adverts:
  - title: ADVERT
    subtitle: ''
    text: |-
      Advert from Byte magazine (january 1977) said :

      ...It gets its speed and power from a selected version of the new Z80 microprocessor that can operate at a 4 Mhz. clock rate (The Z-1 also lets you switch to 2 Mhz. to be compatible with older systems)...\
      ...The Z-1 offers you all kinds of peripherals and softwares. It uses the standard ''S100'' bus supported by over a dozen manufacturers. And all Cromemco peripherals (PROM memory and programmer, Ram memory, analog I/O, color TV interface, etc) just plug into the Z1's sockets...\
      ... The Z-1 comes completely assembled ans tested. It's a quality, commercial grade microcomputer. It is not available as a kit.
    image: null
  comments:
  - author: david
    date: Thursday 26th May 2022
    text: The computer in Wargames was a Wang, and it had an 8" disk drive, which these certainly didn''t, it was quite a callenge just to connect a hex keypad and a cassette recorder !
  - author: Martin (USA)
    date: Tuesday 11th June 2019
    text: |-
      The Z-1 had 3 significant changes from the Imsai 8080 upon which it was based: 1) The Motherboard was replaced with a Cromemco Blitz Bus (the rare version of this bus with the front connector offset to accept the front panel) 2) the CPU was replaced with the Cromemco ZPU, and 3) the film in the front panel was replaced with one that says Cromemco Z-1.

      The Blitz Bus was supposed to handle higher frequency better, to support the 4 MHz ZPU.

      On my Z-1, the fuse was relocated to the rear panel. I suspect this was also done by Cromemco when they created the Z-1, but I don''t have confirmation.
  - author: Penguin
    date: Tuesday 3rd February 2015
    text: Where''s the mouse?
  - author: Tommy (...)
    date: Tuesday 22nd November 2005
    text: |-
      OPPS

      It was the IMSAI 8080

      they look alike
  - author: Tommy (playing halo on my pimped-out 386)
    date: Tuesday 22nd November 2005
    text: |-
      This is the computer from the movie War Games (1983)

      The company Cromemco is still building these\
      on there website, for 8bit programming needs\
      (they have some that run at 90 mhz)
  - author: paul (uk)
    date: Sunday 5th January 2003
    text: thought id post a msg while no one else has, n what an ugly weird thing
  oc_id: 542
  source:
    url: https://web.archive.org/web/20230608222656/http://www.old-computers.com/museum/computer.asp?c=542
    date: '2023-06-08'
---

The Cromemco Z-1 uses an IMSAI chassis, with 22 card slots and a 28 amperes (about 300 watts) power supply. The major innovation of the Z-1 is the use of the 4 Mhz version of the Z-80 processor. It is also equiped with its own 2708 type EPROM burner card.

Like the IMSAI, the Basic version of the Cromemco Z-1 is programmed through the front panel switches, and results are read from the front panel leds... Hopefuly, it is possible to connect a standard Video terminal through the serial port.