--- 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 forum_thread: 36 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 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.