Editing Xerox 820 (section)

===Overview===
The '''Xerox 820-II'''<ref>{{Cite web |title=Digibarn Systems: Xerox 820-II |url=https://www.digibarn.com/collections/systems/xerox820/index.html |access-date=2022-11-25 |website=www.digibarn.com}}</ref> followed in 1982, featuring a Z80A processor clocked at 4.0&nbsp;MHz. Pricing started at {{USD|3000|1982|round=-2}}.<ref name="opmanual">Xerox 820-II Personal Computer Operation Manual, 1982.</ref>

'''Hardware:''' The processor board is located inside the [[cathode-ray tube|CRT]] unit, and includes the Z80A, 64&nbsp;KB of RAM and a boot ROM which enables booting from any of the supported external drives in 8-bit mode.

'''Screen:''' The display is a 24-line, 80-character (7×10 dot matrix) white-on-black monochrome CRT, with software-selectable variations such as [[reverse video]], blinking, low-intensity (equivalent to grey text), and 4×4-resolution graphics.<ref name="opmanual"/>

'''Communication ports:''' These include two 25-pin [[RS-232]] serial ports (including one intended for a Xerox 620 or [[Xerox 630|630]] printer or compatible,<ref>A serially-connected HP LaserJet, or an Apple LaserWriter, or their "Plus" variants, in Diablo emulation mode can be substituted.</ref> and one intended for a modem), and two optional parallel ports which can be added via an internal [[pin header]], usable with a Xerox or other cable.

'''Keyboard:''' A bulky 96-character [[ASCII]] keyboard with a 10-key [[numeric keypad]] and a cursor diamond which otherwise defaults to Ctrl-A to Ctrl-D. It also includes {{keypress|HELP}} and {{keypress|LINE FEED}} keys, and is attached to the back of the CRT unit by a thick cable.<ref name="opmanual"/>

'''Software:''' A typical 820-II comes with CP/M 2.2, diagnostic software, WordStar, and [[Microsoft]]'s [[Xerox BASIC-80|BASIC-80]] [[programming language]].