Martin Scott Goldberg says :
The Sol was not designed by Bob Marsh and the
Osborne was not made a reality by Adam Osborne. Both were designed and
built by Lee Felsenstein, who lived in Bob Marsh's garrage and was the
actual electrical engineer of their stuff. He's also known for being the
moderator of the Home Brew Computer Club. The operating system was written
by the infamous Steve Dompier (the man who made the Altair play music at a
The idea Les Solomon had put forth was for an intelligent terminal, not an
actuall full computer, and that's the way the Sol was presented in Popular
Electronics in 1976. Though it was actually a full blown computer with a
terminal built in.
When Proc Tech folded by 1980, Lee was then hired that year by Adam
Osborne to design and build a "portable" computer. This of
course turned out to be the Osborne
Bob Marsh replies:
The Sol-20 electronics were jointly designed by Lee
F. and me. The mechanical design was managed by Gordon French, in whose
garage the very first Homebrew Computer Club meeting was held. I was out
of work when I founded Processor Technology Corp. (jointly with Gary
Ingram) but not when the Sol was invented. Lee never lived in any garage
(that I know of). We shared use of a garage-like commercial space on
Fourth Street in Berkeley, where Processor Tech later began. Concerning
Osborne Computer Corp. - PTC folded in May 1979, and a year later Lee F
and Adam O were both co-founders of OCC.
Information from John Dowd:
The Sol came with one of three "personality modules", or ROM's.
Consol was one. There was another which turned it into an
intelligent terminal. And then there was SOLOS which was the
stand-alone computer ROM. It had the cassette, parallel and serial
IO interfaces as well as the capability to read memory locations out in
Hexadecimal, insert hex values into memory locations and execute programs
starting at a provided hex location.
The source code for the ROM was
included in the voluminous documentation that came with the Sol kit.
Oh, and the personality module was on a pluggable mini circuit board that
plugged into a right angle connector on the main board. This was
accessible from the rear of the computer. In addition the Sol 20 had a
daughter board with four S100 connectors for adding memory, controllers,
It's biggest drawback I think was its memory mapped video. Memory
ended at C000 because the ROM began there and video memory began at CC00.
This limited contigous memory to 48K.
More technical information from Mike Boyd:
The Sol was born from the VDM-1 Video display board,
list $160 - it was 16 lines of 64 characters - memory mapped.
The designers of the board must have forgot to route the databus across
the board because there was a wide ribbon cable that you had to solder on
the back of the board from one side to another.
The character set was a 2716 EEPROM, and PT supplied two versions - one
with weird characters for the control-characters, like LF being a little
"L" over a little "F" and the other had
"space" characters instead so that you could play Processor
Technology "Space War" with; if you got the wrong character set
- your "LF" ships would shoot at your "CR" ships - not
To scroll the video, you could set the begining line of the display using
an output port.
One of the first software programs was a "patch" that PT
supplied in Basic; that would go and modify MicroSoft basic - to re-direct
the serial output from the teletype to the VDM-1; you still would use the
teletype keyboard to type to your computer.
It was a very fast board, I remember running the output thru a
"Pixie-Verter" (transmitter) to my parents TV set.