---
title: Compaq Portable III
categories:
- Computers
types:
- Professional Computer
origins:
- U.S.A.
years:
- '1987'
cpus:
- Intel 80286
params:
  name: Portable III
  image: /media/museum/photos/compaq_portableiii_system_s2.jpg
  company: /companies/compaq
  company_name: Compaq
  specs:
  - label: NAME
    value: Portable III
  - label: MANUFACTURER
    value: Compaq
  - label: TYPE
    value: Professional Computer
  - label: ORIGIN
    value: U.S.A.
  - label: YEAR
    value: '1987'
  - label: END OF PRODUCTION
    value: Unknown
  - label: BUILT IN LANGUAGE
    value: None
  - label: KEYBOARD
    value: Typewriter type 92 keys with 12 function keys and numeric keypad
  - label: CPU
    value: Intel 80286
  - label: SPEED
    value: 12 MHz
  - label: CO-PROCESSOR
    value: Socket for a 80287 math coprocessor
  - label: RAM
    value: 640 KB up to 2 MB
  - label: VRAM
    value: Unknown
  - label: ROM
    value: 16 KB
  - label: TEXT MODES
    value: 40 or 80 columns x 25 lines
  - label: GRAPHIC MODES
    value: 640 x 200 dots (CGA resolution)
  - label: COLORS
    value: Monochrome orange
  - label: SOUND
    value: Beeper
  - label: SIZE / WEIGHT
    value: 41 (W) x 19.2 (D) x 24.8 (H) cm / 11 kg
  - label: I/O PORTS
    value: Serial, Parallel, Video RGB, expansion bus
  - label: BUILT IN MEDIA
    value: 1 x 1.2 MB FDD, 20 or 40 MB HDD
  - label: OS
    value: MS-DOS 3.1
  - label: POWER SUPPLY
    value: Built-in power supply unit - No battery
  - label: PERIPHERALS
    value: Expansion box with two IBM-AT card slots
  - label: PRICE
    value: $4,990 (20 MB), $5,790 (40 MB)
  tabs:
  - photos
  - adverts
  - hardware
  - links
  forum_thread: 1037
  photos:
  - title: 'PORTABLE III #1'
    subtitle: ''
    text: ''
    image: /media/museum/photos/compaq_portableiii_system_s1.jpg
  - title: 'PORTABLE III #2'
    subtitle: ''
    text: ''
    image: /media/museum/photos/compaq_portableiii_system_s4.jpg
  - title: TOP VIEW
    subtitle: ''
    text: ''
    image: /media/museum/photos/compaq_portableiii_topview_s1.jpg
  - title: RIGHT SIDE
    subtitle: ''
    text: ''
    image: /media/museum/photos/compaq_portableiii_rightside_s1.jpg
  - title: MOTHERBOARD
    subtitle: ''
    text: |-
      Only one board fulfil all of the functions of a standard AT machine, including video, FDD and HDD control and various I/O. A small daugter card is used to manage the plasma display.\
      **(1)** 2 x 512 KB RAM modules. Only 640 KB is used by programs\
      **(2)** Optional card slots (RAM and modem card)\
      **(3)** Hard-disk drive data connectors\
      **(4)** Bus expansion connector, mainly used by the external expansion box\
      **(5)** FDD and HDD power connectors\
      **(6)** Floppy-disk drive data connector\
      **(7)** Four Fujitsu custom chips carry out most of the tasks\
      **(8)** Power supply connector\
      **(9)** 80286-12 CPU covered by its cooling plate (very simple system compared to nowadays massive cooling systems).
    image: /media/museum/photos/compaq_portableiii_mainboard_s1.jpg
  - title: 'MOTHERBOARD #2'
    subtitle: ''
    text: |-
      In some versions of the motherboard, a "Dallas" clock chip (1) which also included a rechargeable CMOS battery, replaced the original CMOS battery which location was then empty (2).

      If you need to replace the Dallas chip, this [link](http://www.maxim-ic.com/appnotes.cfm/appnote_number/769) may help you.
    image: /media/museum/photos/compaq_portableiii_withoutbattery_s1.jpg
  - title: PLASMA DISPLAY
    subtitle: ''
    text: Rear side of the OKI plasma display.
    image: /media/museum/photos/compaq_portableiii_display_s1.jpg
  - title: REAR SIDE
    subtitle: ''
    text: |-
      From left to right:\
      • Expansion connector, covered by a sliding lid when not used,\
      • RGB monitor connector,\
      • Serial connector,\
      • Parallel connector,\
      • AC socket and switch.
    image: /media/museum/photos/compaq_portableiii_rearside_s1.jpg
  - title: NYLON BAG
    subtitle: ''
    text: |-
      This bag could carry a complete system along with its expansion box, manuals and software.\
      An expensive leather bag was also available.
    image: /media/museum/photos/compaq_portableiii_bag_s1.jpg
  adverts:
  - title: '8-PAGE US ADVERT #1'
    subtitle: ''
    text: ''
    image: /media/museum/pubs/compaq_portableiii_pub_s1.jpg
  - title: '8-PAGE US ADVERT #2'
    subtitle: ''
    text: ''
    image: /media/museum/pubs/compaq_portableiii_pub_s2.jpg
  - title: '8-PAGE US ADVERT #3'
    subtitle: ''
    text: ''
    image: /media/museum/pubs/compaq_portableiii_pub_s3.jpg
  - title: '8-PAGE US ADVERT #4'
    subtitle: ''
    text: ''
    image: /media/museum/pubs/compaq_portableiii_pub_s4.jpg
  - title: '8-PAGE US ADVERT #5'
    subtitle: ''
    text: ''
    image: /media/museum/pubs/compaq_portableiii_pub_s5.jpg
  hardware:
  - title: EXPANSION BOX
    subtitle: ''
    text: This expansion box provided two 16-bit expansion slots.
    image: /media/museum/hardware/compaq_portableiii_expansionbox_s2.jpg
  - title: OPENED
    subtitle: ''
    text: The box holds a X25 network card.
    image: /media/museum/hardware/compaq_portableiii_expansionbox_s1.jpg
  links:
  - title: Web Wiz CAPTCHA
    url: http://www.webwizcaptcha.com
    text: ''
  related:
  - /museum/compaq-portable
  - /museum/compaq-portable-386
  - /museum/compaq-portable-ii
  oc_id: 1064
  source:
    url: https://web.archive.org/web/20230608222727/http://www.old-computers.com/museum/computer.asp?c=1064
    date: '2023-06-08'
---

When Compaq launched its Portable III, the lauch was timed to occurs simultaneously in twelve countries around the world, in keeping with Compaq's showmanship style.

The Portable III previously rumoured to be the smallest, lightest and fastest 386 machine but Compaq only had a 286-12 mainboard ready to be mass produced. The 386 version would follow about one year later.

Compaq actually released a 286 version to restore its Number One spot in the portable market, under the pressure from Toshiba with its T-1100 and T-3100 and Zenith with its Z-181.

The design of the Portable II had been deeply improved over the earlier Compaq portable machines. It was half the size and its footprint occupied half the space of the first Compaq [Portable](/museum/compaq-portable/). The most remarquable feature was its neat gas plasma display wich lifted up and swiveled so that it could be placed in a good position for reading.

The machine shipped with either a 20 MB or 40 MB hard-disk. Two internal cards could be added, a RAM card (up to 2 MB) and a 1200-baud modem card. An external expansion box allowed to add two standard IBM-AT cards and carry them along with the computer.

---

**Ryan Schweitzer** adds:\
It also has a proprietary graphics mode that allows it to run at true 640 x 400 mode. I ran both a copy of Windows/286 2.11 (yes, 2.11 :) ) that had a Compaq Portable display driver for 640 x 400 (if I recall correctly), and also had an installation of GeoWorks Ensemble 2.0 on it, that could make the display run perfectly at 640 x 400 if the display drivers for the AT&T 6300 (also 640x400) were used!!!\
I think ensemble's AT&T driver might of used the same calls/registers/interrupts/whatnot to the Portable's graphics chipset, or maybe even possibly the Portable used the same graphics chipset as the AT&T 6300.

**Nancy Hackett's** bad experience:\
Oh, did this machine have problems! I went through four of those nifty plasma monitors, several hard drives, two factory rebuilds, and an uncounted number of motherboards trying to track down internal error codes that Compaq said didn't exist!\
It came (not so) lovingly to be known as "The Compaq from Hell" with the motherboard rumored to be numbered "666". Both the maintenance manager's and the Compaq regional rep's hands would sweat every time I lugged it in. The spectacular finale was when the power supply blew, shooting blue flames 18" out the side! LOL! That was an experience!