website/content/museum/xerox-820.md

---
title: Xerox 820
categories:
- Computers
types:
- Professional Computer
origins:
- U.S.A.
years:
- '1981'
cpus:
- Zilog Z80 A
params:
  name: '820'
  image: /media/museum/photos/xerox_820_system_s1.jpg
  company: /companies/xerox
  company_name: Xerox
  specs:
  - label: NAME
    value: '820'
  - label: MANUFACTURER
    value: Xerox
  - label: TYPE
    value: Professional Computer
  - label: ORIGIN
    value: U.S.A.
  - label: YEAR
    value: '1981'
  - label: END OF PRODUCTION
    value: '1985'
  - label: BUILT IN LANGUAGE
    value: Basic 80 delivered on disk
  - label: KEYBOARD
    value: AZERTY/QWERTY, full-stroke keyboard with separated keyboard
  - label: CPU
    value: Zilog Z80 A
  - label: SPEED
    value: 2,5 Mhz
  - label: RAM
    value: 64 kb
  - label: ROM
    value: from 4 kb to 8 kb
  - label: TEXT MODES
    value: 80 x 24
  - label: GRAPHIC MODES
    value: Unknown
  - label: COLORS
    value: Black and white 12'' monitor
  - label: SOUND
    value: Unknown
  - label: SIZE / WEIGHT
    value: 'Main unit/monitor : 32,8 x 38,1 x 34,3 cm / 13,6 kg'
  - label: I/O PORTS
    value: Serial 9600 bauds, Internal Expansion Slot, External Floppy Connector
  - label: BUILT IN MEDIA
    value: |-
      One or two 5.25'' disk-drives (80 KB formatted each)\
      One or two 8'' disk-drives (160KB each)
  - label: OS
    value: CP/ M 2.2
  - label: POWER SUPPLY
    value: Built-in PSU
  - label: PERIPHERALS
    value: Printers, additional disks
  - label: PRICE
    value: With double 8'' disks = 3900 (France, 82)
  tabs:
  - photos
  - adverts
  - hardware
  photos:
  - title: RUNNING SYSTEM
    subtitle: ''
    text: The Xerox 820 is running XWP, a version of the WordStar word processor specially adapted for the Xerox 820.
    image: /media/museum/photos/xerox_820_systemrunning_s1.jpg
  - title: THE KEYBOARD
    subtitle: ''
    text: The keyboard, made by a third company in USA, was solidly-built and well adapted to word processing and intensive typing.
    image: /media/museum/photos/xerox_820_keyboard_s1.jpg
  - title: REAR SIDE
    subtitle: ''
    text: |-
      **(1)** Reset switch\
      **(2)** Disk drives unit connector\
      **(3)** Keyboard connector\
      **(4)** Parallel printer connector\
      **(5)** Serial comm connector
    image: /media/museum/photos/xerox_820_rear_s1.jpg
  - title: FD UNIT
    subtitle: ''
    text: |-
      The FD unit holds two 5.25" single side, single density drives of the first generation. The mechanism was the same as the Apple II disc drives (an eccentric wheel was used to move the head).\
      The Xerox 820 was also bundled with a single or dual 8" FD unit.
    image: /media/museum/photos/xerox_820_driveunit_s1.jpg
  - title: INSIDE
    subtitle: ''
    text: |-
      **(1)** Switching power supply. Comes from Aztec, Hong-Kong, also supplies the 5.25 FD unit\
      **(2)** Mainboard\
      **(3)** Video circuit.
    image: /media/museum/photos/xerox_820_inside_s1.jpg
  - title: MAINBOARD
    subtitle: ''
    text: |-
      **(1)** Double density floppy disk controller add-on card. The diskette capacity went from 85 KB to 170 KB\
      **(2)** Z80 PIO (Parallel Input Output). All the components of the Z80 family come from Mostek\
      **(3)** Z80 CTC (Counter Timer)\
      **(4)** Mostek 3884 serial I/O controller\
      **(5)** 32 x National Semiconductor MM5290 RAM chips hold 64 KB of RAM\
      **(6)** BIOS ROMs\
      **(7)** Z80 processor
    image: /media/museum/photos/xerox_820_mainboard_1.jpg
  - title: XEROX MANUALS
    subtitle: ''
    text: Applications and Reference guide (binder) and Word processing handbook
    image: /media/museum/photos/xerox_820_manuals_s1.jpg
  - title: SOFTWARE DISKETTES
    subtitle: ''
    text: Some of the bundled Xerox software diskettes
    image: /media/museum/photos/xerox_820_diskettes_s1.jpg
  - title: PACKED
    subtitle: ''
    text: Main unit, keyboard and FD unit packed in original Xerox boxes.
    image: /media/museum/photos/xerox_820_inbox_s1.jpg
  adverts:
  - title: FRENCH ADVERT
    subtitle: ''
    text: ''
    image: /media/museum/pubs/xerox_820_pub_1.jpg
  hardware:
  - title: DOT-MATRIX PRINTER
    subtitle: ''
    text: This 132-column printer (actually a Microline 82) still used old typewriter spool ribons but was quite indesctructible.
    image: /media/museum/hardware/xerox_820_printer_s1.jpg
  comments:
  - author: Ed Hase (US)
    date: Wednesday 3rd June 2020
    text: |-
      Mr. Bla Bla Bla\
      The 820 mother board went into the surplus market after its failure.\
      It was based on the Fergie board and had a large following in the aftermarket.\
      Some were sold fully populated and some as a bare board.\
      Mine had a SCSI controller by Emerald Microware (two 5 Meg drives)\
      A floppy controller daughter board (2-5 ¼” and 2- 8” high density floppies).\
      We also put in higher clock speed main chips to speed it up.\
      I was saving up for a ram board, when I sold it to someone developing hard ware on the Z80 platform.
  - author: Bla Bla Bla My daddy worked for Xerox...
    date: Thursday 24th November 2016
    text: |-
      Bla Bla Bla, My daddy worked for Xerox and I learned DIR...\
      This is the most plain generic unimaginative piece of space junk Xerox ever produced.

      Shame on them! They invented the Alto!
  - author: Steve H (Houston)
    date: Wednesday 26th October 2016
    text: This was my first computer, dad worked for Xerox. I remember going thru the user manual and learning how to navigate the directories. Was proud of myself at age 10 to find stuff. This model had a fun little game named, "Barney." Think you had to type dir/ w or dir/p to find it.
  - author: Nathan Lindsey (USA)
    date: Wednesday 12th August 2015
    text: My Dad worked for Xerox and this was my first computer. I think it''s still in my Parents'' basement.
  - author: Maurice (Virginia, USA)
    date: Monday 10th October 2011
    text: |-
      Maureen, I''m probably too late, but I have an 820II with monitor, keyboard and dual floppy drives. Manuals, too. I would like to sell it.

      Maurice
  - author: Greg Bergman
    date: Sunday 17th April 2011
    text: I have a shrink wrapped box with Digital Research CP/M Operating System labeled Xerox 1800 with a reorder number 8R1245. It came with my Digital Rainbow purchase years ago on ebay. It appears to be designed for a Xerox 820. Is this the operating system your machines ran?
  - author: Maureen Limon (Virginia, USA)
    date: Monday 28th February 2011
    text: |-
      Does anyone know where I could rent the Xerox 820 to be used as a prop for a photo shot? I need it rather soon.\
      Thanks in advance
  - author: Wayne (UK)
    date: Tuesday 8th February 2011
    text: I had two of these obtained from a junk store in the mid 90''s which I never succesfully got going. Mine had the 8086 board fitted and had twin 8" floppies and a 8" Hard Drive. I am quite sure the drive interface was SASI (Pre SCSI?) What did surprise me was that the drives were AC powered (240v here) and had really nice induction motors. Hard Drive was 2 platter with clear perpex cover.
  - author: Joe K
    date: Saturday 3rd July 2010
    text: I finally got rid of my 820 a few years ago. Pretty sure my Uncle had 8" floppy drive for his, though mine was 5 1/4. I still have the manuals if anyone wants them, pls. e-mail - jkowski@sbcglobal.net
  oc_id: 15
  source:
    url: https://web.archive.org/web/20230604042045/http://www.old-computers.com/museum/computer.asp?c=15
    date: '2023-06-04'
---

The Model 820 is an attempt from Rank Xerox to enter the professional micro-computer market. But the 820 is a bit weak with its Z80 at only 2,5 Mhz and its 96kb 5''1/4 disk-drives (83k formated). Fortunately higher capacity 8'' disk-drives were also available (300 kb each). Apparently a 10Mb hard-disk was also proposed.

The communication was focused on the fact that the Xerox 820 could suit to a lot of professions, and indeed, thanks to its CP/M compatibility a lot of different software was available (Wordprocessor, Supercalc, AGIS billing, SAARI, Wordstar 3.0, Mailmerge 3.0, Supersort 1.6, Calcstar, Infostar 1.0, FIGARO hair-dresser management, etc...).

The Xerox 820 was followed by the [Xerox 820-II](/museum/xerox-820-ii/).

---

**Greg Eshelman** reports us these tips :\
Here is a tip. Most of the drive boxes with single sided drives used a cable with fewer wires than the ones with double sided drives. All you need to do is carefully move one of the ground wires at both ends of the cable to the side select pin location and you can swap in a pair of ordinary TEAC or Tandon 360k drives. :) For the end that plugs into the 820 you need a special tool for removing and inserting the pins. A tiny screwdriver works on the other connectors, you have to do it on both of the drive connectors.

One "bug" with the 820 series is it cannot tell if the drives are single or double sided and will blindly "format" double sided in a single sided drive. This works until you try to put too much on a disk then it messes up and you lose everything on the disk!

**Steve Bolingbroke** reports:\
Xerox had a proprietory operating system from a previous computer (mini ?) range , called M80 (?). I was part of project team that ported the old O/S to the 820 so that it dual booted and could run business apps writen for the previous range. We got it to work exactly the same except the command lines (reserved bottom two lines of the screen) had a dark stripe between them. We called it the "Go Faster Stripe".

**Bill** adds:\
The 820 was compatible with the APPLE II Pascal format. I worked for Xerox from 82 thru 93 and had an 820 on my desk. We took the Turbo Pascal binary from the Apple II and download it via Xmodem to the 820 and it ran very well. We wrote a early BBS with this environment.