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.

Flipping the 820-II's console between 8-bit and 16-bit modes on an 820-II which is equipped with the optional 16-bit processor card is accomplished by a keyboard control command.

Xerox 820-II component parts were available from Xerox outlet stores at quite reasonable prices, and it was not uncommon to convert surplus (but new) 128 KB 16-bit processor cards to 512 KB by the substitution of sixteen 41256 DRAM chips for the card's usual sixteen 4164 DRAM chips (both are 16-pin DIPs—pin 1 is unused on a 4164 and becomes A8 on a 41256), plus the addition of two ICs (one 74F02 and one 74F08, or two user-modified PALs) for controlling the 41256's 9th address row and column (not found on 4164s), thereby achieving a four-times increase in RAM without the use of a "daughter" card (which can only achieve a two-times increase in RAM).

[10] [11] The CRT unit contains the processor, and a large port on the back connected via heavy cable to a disk drive, allowing a wide variety of configurations.

One can also access a "(T)ypewriter" mode for direct interface with the serial printer port and basic typing on screen.

Further, (documented) calls to BOS subroutines allows a skilled user or program to restart the system, perform disk operations, take keyboard input, or write to the display.

The reviewer criticized the keyboard's contact bounce, slow disk access, and "pieced-together ... minimal" documentation, and warned customers against the Xerox-customized WordStar.

He reported that three of the four computers' disk-drive units his company had purchased had problems, and "strongly recommend an 820 owner get a service contract".

The reviewer concluded that while the 820 "could be a fine office computer, its faults are so egregious that they indicate a basic lack of attention to detail on the part of Xerox".

The Rosen Electronics Letter also unfavorably reviewed the 820 in June 1981, however, describing it as a disappointing, "me too" product for a leading technology company like Xerox.

[15][16] They did choose the PC, introduced one month after the 820; Yankee Group said after the latter's discontinuation that it "sort of got blown away right then and there by the IBM announcement".