Talk:Xerox 820

FYI: The June 1986 issue of QEX has a fair amount of technical information on the Xerox 820-1 and 820-2. Sagsaw 20:23, 14 April 2006 (UTC)

Information Processor

The full name of these computers were Xerox 820-II Information Processor. Base configuration of the II included two single sided, double density, full height 5.25" floppy drives. The system supported double sided drives but upgrading was a simple matter of swapping the drives. The drive cable for the single sided drives did not have a wire for the head select signal.

Fortunately Xerox used a cable made of individual wires in twisted pairs, spiral wrapped in copper foil, inside a heavy plastic cover. It was fairly easy to move one of the ground wires at each connector to the head select position to use double sided drives and avoid buying a new cable.

A dual 8" floppy drive was available, primarily used with the original 820 but also compatable with the 820-II.

An 820 could be upgraded to an 820-II by swapping the circuit boards. Likewise, the 820 boards would fit the 820-II case.

Two keyboards were available, a "low profile" model, more like a typical PC keyboard, and the standard one which was in a rather bulky case which tapered from nearly 2" high at the front to over 3" high at the back, with a large border on top around all sides of the keys.

The printer sold with the 820-II was a Xerox branded Diablo 630 daisy wheel with a 15" wide carriage. Heavy, loud and fast, unless it was commanded to do bold, double-strike, underline, then it was just heavy and even louder.

The 820-II had an internal pin header for a parallel port. Xerox sold a cable to use it, which simply laid between the top of the ports panel and the bottom of the upper case, with a metal strap to help secure it. Since the installation instructions included the wiring diagram, it was easy for a hobbyist to construct his own parallel interface adaptor cable. (I had an Epson LX-800 connected to the parallel port for printing drafts while the Diablo was used for letters.)

There was no graphics option available for these Xerox computers, they were strictly text only.

The final model in the 820 line had a slightly larger monitor with a black facia added and either included as standard or as an option (I forget which) an 8088 CPU for running Microsoft DOS and DOS programs in addition to the standard Z-80A for CP/M.— Preceding unsigned comment added by 67.136.145.250 (talk) 07:49, 26 April 2006 (UTC)

820-II reference additions

I was able to acquire an 820-II a short while ago with copies of system reference manuals and other documentation. The different 820 models have been set off into their own sections, and for now I'm expanding the 820-II section to reflect the extra information I have, including eventually with pictures; I'll expand the other models as I find info about them from other sources, as well.

Vintagejonny 22:50, 31 December 2006 (UTC)

Model 16/8 - 512 MB

The section about the "Model 16/8" mentions "512 MB" two times but it looks like it should be "512 KB" though.

Nomike (talk) 04:30, 21 May 2014 (UTC)