---
title: Digital Equipment Corporation DECmate III
categories:
- Computers
types:
- Professional Computer
origins:
- U.S.A.
years:
- '1984'
cpus:
- Harris 6120 cpu
params:
  name: DECmate III
  image: /media/museum/photos/dec_decmate_iii.jpg
  company: /companies/digital-equipment-corporation
  company_name: Digital Equipment Corporation
  specs:
  - label: NAME
    value: DECmate III
  - label: MANUFACTURER
    value: Digital Equipment Corporation
  - label: TYPE
    value: Professional Computer
  - label: ORIGIN
    value: U.S.A.
  - label: YEAR
    value: '1984'
  - label: END OF PRODUCTION
    value: '1990'
  - label: KEYBOARD
    value: QWERTY full-stroke professionnal keyboard
  - label: CPU
    value: Harris 6120 cpu (12 bits)
  - label: SPEED
    value: 8 Mhz
  - label: RAM
    value: 32k (+ 32k for dedicated control panel functions)
  - label: TEXT MODES
    value: 80 x 24 and 132 x 24
  - label: COLORS
    value: 'No'
  - label: SIZE / WEIGHT
    value: 32 x 28 x 14 cm / 8 kg
  - label: I/O PORTS
    value: RS232C, printer, data-communication port
  - label: BUILT IN MEDIA
    value: 2 x 5
  - label: OS
    value: OS/278
  - label: POWER SUPPLY
    value: Built-in PSU
  - label: PERIPHERALS
    value: |-
      Color graphics board\
      APU board : Z80 based board for CP/M use\
      XPU board : 8088 based board for MS/DOS use\
      Modem
  - label: PRICE
    value: approx. 2700$
  tabs:
  - photos
  - links
  forum_thread: 462
  photos:
  - title: MAIN UNIT
    subtitle: ''
    text: ''
    image: /media/museum/photos/dec_decmate3_system_s1.jpg
  links:
  - title: DECmate FAQ by Charles J. Lasner
    url: http://www.ibiblio.org/pub/academic/computer-science/history/pdp-8/docs/dminfo.faq
    text: DECmate specific information
  - title: PDP8 page by Douglas W. Jones
    url: http://www.cs.uiowa.edu/~jones/pdp8/
    text: Infos and links about the PDP8 machines
  - title: '''''What is a DECmate III ?'''' from the PDP-8 FAQ'
    url: http://www.faqs.org/faqs/dec-faq/pdp8-models/section-15.html
    text: Useful
  oc_id: 468
  source:
    url: https://web.archive.org/web/20230202174529/http://www.old-computers.com/museum/computer.asp?c=468
    date: '2023-02-02'
---

This computer is still based on the PDP-8 architecture but is less "opened" than the DECmate II. Indeed DEC realised that the PDP-8 based products were rarely expanded to their full potential. Thus, they conceived the DECmate III wich offers less expansion possibilities but which was also cheaper.\
As the last incarnation of the PDP-8 technology, the DECmate III use a single chip containing all the PDP-8 hardware !

Only one pair of 5''1/4 disk-drives (RX50) is supported and it is not possible to connect a Hard-Drive. But unlike the DECmate II, a color monitor can replace the monochrom screen.

It was mainly intended for professionnal word-processing, but could also run other software including OS/278. The DECmate III was compatible with the DECmate II.

In 1985, a DECmate III+ was sold with a hard disk controller built-in and overall completely new hardware components, though still compatible with the DECmate II and III.

The DECmate computers were marketed by Digital Equipment Corporation.