website/content/museum/xerox-820.md

title, categories, types, origins, years, cpus, params

title	categories	types	origins	years	cpus	params
Xerox 820	Computers	Professional Computer	U.S.A.	1981	Zilog Z80 A	name image company company_name specs tabs forum_thread photos adverts hardware oc_id source 820 /media/museum/photos/xerox_820_system_s1.jpg /companies/xerox Xerox label value NAME 820 label value MANUFACTURER Xerox label value TYPE Professional Computer label value ORIGIN U.S.A. label value YEAR 1981 label value END OF PRODUCTION 1985 label value BUILT IN LANGUAGE Basic 80 delivered on disk label value KEYBOARD AZERTY/QWERTY, full-stroke keyboard with separated keyboard label value CPU Zilog Z80 A label value SPEED 2,5 Mhz label value RAM 64 kb label value ROM from 4 kb to 8 kb label value TEXT MODES 80 x 24 label value GRAPHIC MODES Unknown label value COLORS Black and white 12'' monitor label value SOUND Unknown label value SIZE / WEIGHT Main unit/monitor : 32,8 x 38,1 x 34,3 cm / 13,6 kg label value I/O PORTS Serial 9600 bauds, Internal Expansion Slot, External Floppy Connector label value BUILT IN MEDIA One or two 5.25'' disk-drives (80 KB formatted each)\ One or two 8'' disk-drives (160KB each) label value OS CP/ M 2.2 label value POWER SUPPLY Built-in PSU label value PERIPHERALS Printers, additional disks label value PRICE With double 8'' disks = 3900 (France, 82) photos adverts hardware 36 title subtitle text image RUNNING SYSTEM The Xerox 820 is running XWP, a version of the WordStar word processor specially adapted for the Xerox 820. /media/museum/photos/xerox_820_systemrunning_s1.jpg title subtitle text image THE KEYBOARD The keyboard, made by a third company in USA, was solidly-built and well adapted to word processing and intensive typing. /media/museum/photos/xerox_820_keyboard_s1.jpg title subtitle text image REAR SIDE **(1)** Reset switch\ **(2)** Disk drives unit connector\ **(3)** Keyboard connector\ **(4)** Parallel printer connector\ **(5)** Serial comm connector /media/museum/photos/xerox_820_rear_s1.jpg title subtitle text image FD UNIT 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. /media/museum/photos/xerox_820_driveunit_s1.jpg title subtitle text image INSIDE **(1)** Switching power supply. Comes from Aztec, Hong-Kong, also supplies the 5.25 FD unit\ **(2)** Mainboard\ **(3)** Video circuit. /media/museum/photos/xerox_820_inside_s1.jpg title subtitle text image MAINBOARD **(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 /media/museum/photos/xerox_820_mainboard_1.jpg title subtitle text image XEROX MANUALS Applications and Reference guide (binder) and Word processing handbook /media/museum/photos/xerox_820_manuals_s1.jpg title subtitle text image SOFTWARE DISKETTES Some of the bundled Xerox software diskettes /media/museum/photos/xerox_820_diskettes_s1.jpg title subtitle text image PACKED Main unit, keyboard and FD unit packed in original Xerox boxes. /media/museum/photos/xerox_820_inbox_s1.jpg title subtitle text image FRENCH ADVERT /media/museum/pubs/xerox_820_pub_1.jpg title subtitle text image DOT-MATRIX PRINTER This 132-column printer (actually a Microline 82) still used old typewriter spool ribons but was quite indesctructible. /media/museum/hardware/xerox_820_printer_s1.jpg 15 url date https://web.archive.org/web/20230604042045/http://www.old-computers.com/museum/computer.asp?c=15 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.

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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.