Home | About | Collections | Stories | Help! | News & Links | Friends | Lets Talk! | Events & Visiting | Search

Alan O Freier on the "D*" Machines, the Dolphin, Dorado, Dandelion and more

Mesa machine names all started with the letter 'D' and were collectively known as D* (pronounced, "Dee star") machines. The first two machines were simply D0 and D1. The D0 was later labeled as the Dolphin and the D1 as the Dorado, both named after fish, though I don't remember why. Chuck Thacker was the principle designer of both.

EM009, John Wick's original D0 Dolphin
See our pages on the Dolphin here

See the Star 8010 (Dandelion) here

The particular machine you picked up (or what's left of it) was John Wick's personal machine. It is specifically "engineering model # 009." EM009 is reported to be the first D* machine to ever execute a Mesa PrincOps (see complete web documentation here, thanks Alan Freier) instruction.

The original Mesa language definition was started as a joint project between SRI-ARC and PARC (pre SDD, Xerox System's Development Division) . There was lots of arguments about a new language or an MOL (Mesa Object Language), but everyone agreed that strong data typing was needed. The team consisted of Jim Mitchell and Butler Lampson from PARC and Charles Irby, Paxton and Smokey Wallace from SRI, and others whose names will have to be dredged from archives for the "datatyping" draft document.

John Wick was the keeper and protector of the architecture in later days, but the language and basic architecture pre-date him. The Mesa language was designed by Jim Mitchell, Ed Satterthwaite and Chuck Geschke. The Mesa byte-coded instruction set was designed by Butler Lampson and Chuck Thacker and originally implemented as an emulator on TENEX and in microcode on the Alto. Evolution of the architecture from 1976 on was primarily John and Richard Johnsson with lots of input from the others. John was the primary author of the PrincOps document.

The D0 was also used as a platform for developing systems that later ran on Dandelions (aka, 8010s). In that role they first ran in "Alto emulation" mode, and then later ran in pure Mesa PrincOps mode, using Tajo, the Mesa development environment. See Alan's "Wildflower" web site that was actually hosted for a time on an actual Dandelion with a custom built web server.

Two Dandelion (Xerox 8010 Star) Workstations

Tajo is the first of the usable systems built on top of Pilot, the operating system. I was the 4th person in the world to have an "all Mesa office," forsaking forever the Alto emulation mode. The D0 that I had was Pre-prototype 003 (PPM003) and was named "SuchADeal." SuchADeal was employed as a router within Xerox until the late '80s, when, due to everyone's intense feelings for that machine and D0s in general, it was bludgeoned to death with sledge hammers in the Bayhill office parking lot (literally).

The D0 never really made it commercially, though there were a few placed that ran Lisp. They were also used for some time internally as routers, such as SuchADeal. Until the construction of the Dicentra, they were the only machine capable of routing between 3Mbit ethernet and 10Mbit Ethernet.

An original drawing describing Ethernet by Bob Metcalfe (not the first drawing)

I don't know what boards are left in EM009. At least one of them is an Multiple Input/Output Control Processor (MIOCP). It embodies hardware to control serial I/O and a floppy disk. I suspect one of the other boards is the High Speed Input Output controller (HSIO) and maybe some memory. Some of them are stitch weld boards.

Stitch welding was a pseudo automated operation. The board layout was initially done on an Alto using a PARC developed tool called Sil. Output from Sil was then run through another program (Layout) to generate a wire wrap list. This file was then fed into an Alto controlling a stitch weld machine (run primarily by a fine lady named Rosemary). That machine would route and connect the wires to the proper terminals on the back side of the board. After that process, there was still quite a lot of had wire routing left to be done. Once the board design was settled, the design would probably be moved to multi-layer boards, state of the art in the late '70s.

Above are two Xerox org charts from the early '80s which help place some of the people related to the 8010

Some more views of the Dolphin which Alan O. Freier donated to the DigiBarn museum in February 2002, along with two Dandelion (Xerox 8010 Stars)

Cleaning up the D0 Dolphin
Alan and his wife cleaning up old EM009
See our pages on the Dolphin here
Getting more Xerox documentation ready to go the DigiBarn

Know anything more about anything you see here? Contact us!

See Also:

The Digibarn's extensive collection of Xerox computers and other artifacts

Please send site comments to our Webmaster.
Please see our notices about the content of this site and its usage.
(cc) 1998- Digibarn Computer Museum, some rights reserved under this Creative Commons license.