The display of Xerox 820 is a 24-line CRT, it has a bulky 96-character keyboard and its communication ports are two 25-pin RS-232 which was introduced in 1960.
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. Communication ports These include two 25-pin RS-232 serial ports (including one intended for a Xerox 620 or 630 printer or compatible, 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. In telecommunications, RS-232, Recommended Standard 232 is a standard originally introduced in 1960 for serial communication transmission of data. Screen: The display is a 24-line, 80-character (710 dot matrix) white-on-black monochrome CRT, with software-selectable variations such as reverse video, blinking, low-intensity (equivalent to grey text), and 44-resolution graphics. 
