Ted Kehl's wire-wrapping facilities and the "Logic Machine" - PRELIMINARY

This document copyright Herbert R. Johnson 2012. Updated Aug 13 2012.
To return to my Digital Research and CP/M history page click here.


My Web site has a substantive history of hardware and software work in the early 1970's, around the development of CP/M by Dr. Gary Kildall. My site discusses Dr. Torode's work of the 1970's around Kildall's DRI founding at this Web link. The history of Kildall, his colleagues, and of Digital Research Inc. is discussed at this Web link. We'll add other links as this document is edited.

Charlie Garthwaite is a former Ph.D student of Dr. Theodore Kehl, both at the University of Washington. Digital Research co-founder Gary Kildall also got his Ph. D. in Computer Science at the University of Washington, in 1972. Dr. Kehl was also the Ph. D advisor for John Torode, who got his degree in 1972. In the early 1970's, Torode, Kehl and others (including Garthwaite) developed at the University of Washington a number of hardware logic design, support and construction systems. In 1974-5, Torode provided critical hardware support for Gary Kildall, designing and building a floppy controller for Kildall's first 8080 CP/M system in 1974-5. Both Kildall and Torode subsequently developed large companies from that work.

In late 2010, Charlie contacted me about my Web pages on Kehl, Torode and Kildall. He offered some small corrections, and some discussions about Dr. Kehl's facilities in the period, through 2012. He provided the material on this Web page and supporting information and discussion.

Charle told me in 2010: "My associates in Kehl's hardware lab were [John] Torode & Ken Burkhardt, who went on to co-found Dialogic, a PC-based telephony firm later purchased & subsequently sold by Intel. The hardware lab was physically located in the Medical School Physiology & Biophysics Dept. where Ted K. held a joint appointment. So I only know by reputation Gary and Rolander, who was in the EE Dept. which was then quite separate from CSci."

Charlie is still in touch with Dr. Kehl in 2012. The following is Charlie's discussion of Kehl's semi-automated wire wrapping facility in Kehl's lab; some background about minicomputers and their relation to Dr. Torode's work with programmed controllers; and some of Dr. Kehl's activites into the 1980's.

Wire-wrapping was a critical technology during this period of hardware development and production. "Wire wrap" is a means of wiring together component sockets and connectors, pin to pin; manually for prototypes, semi-automated for production work. Each connection is a tight multi-turn wrap of a silver-coated wire, around four cornered gold or silver-plated posts. The sharp corners of the posts produced pressure welds with the wires, so these were superior to solder connections. Wire-wrapping can be done manually with simple hand or powered tools. It was ideal for prototypes for decades in the 20th century, and for small run productions in the days when computer models were produced in dozens or hundreds. It's still an option today.

- Herb Johnson

Kehl's Hardware Lab

"The University of Washington Academic Computer Center operated a CDC 6400 and later a Cyber 73, which were only two of 90 computers at the University of Washington. The Physiology & Biophysics Dept. had 3 of the Packard Bell 440 which later became Raytheon 520 midi-computers. [note: Dr. Kehl's Ph D was in Physiology & Biophysics. He joined the U of W department of that name, and greatly contributed to the start of the U of W Computer Science department. - Herb]

"The term 'Logic Machine' meant the micro-controller architecture of the Torode & Burkhardt Ph. D theses [in 1972]. The mini-computer was known as 'Logic Machine Minicomputer' or LM 'squared' which sloppy typography perverted to 'LM2'. There was but one version of LMM although 'continuous improvement' was rampant [with a nod to VW and later the Japanese]. More than ~15 LMM were deployed at ~10 university medical schools in N. America."

"[Kehl's wire-wrapping machine] was locally fabricated and operated by a succession of nursing school and other students. The machine positioned a pedestal to the appropriate pin position, printed on an ASR-33 Teletype was the wire end's coordinates and the length of wire. A hand held wire-wrap tool resting on the pedestal was then employed."

"We etched PCB board wire-wrap panels with alternating VDC and GND 'fingers' extending from buss on edges. The machine positioned and operated an air-powered drill to drill holes for the DIP socket pins and de-coupling capacitor leads. The hole pattern was continuous & accommodated 0.3" center DIP packages of mostly 74F-series TTL logic IC's. Some 74LS and 74S was also employed. NMOS memory 'paddle board' PCBs sat perpendicular to the main board on 'Berg pins'."

"Wire & Drill lists were generated by a Fortran program maintained by Bill Beckett running on the UW Computer Center CDC 6400 system. Half-inch magnetic tapes from the CDC were converted to paper-tape on our Raytheon/Packard Bell midi-computers. More primitive versions of the list facility ran on the 520/440. A Raytheon 700 series mini-computer and later a LM2 ran the positioning table machine. The LM2 ran an enhanced Raytheon 7xx instruction set."

"There were a number of board sizes, 3-4 of the largest size mounted in an aluminum frame that was the back door of a standard ~6' tall 19"wide equipment rack housing the LM2 mini-computer. The door had two hinges so the back cover opened to access the wire-wrap pins. Cooling fans pulled air over the pins."

"Smaller boards with edge connector fingers plugged into I/O [subracks based on Vector brand 4.5" X 6.5" card racks] mounted in the front of the rack to provide custom interfaces to lab gear such as a multi-channel A to D & D to A converter box. The remainder was occupied by an 8" Shugart floppy drive, a 9-track Pertec tape drive, a shelf for video monitor, core memory box on early systems, & power supply."

Charlie provided a catalog reference to a Vector EIA VectorPak , a 19" wide rack which holds a number of 4.5" X 6.5" circuit boards connected by some kind of backplane or cross-wiring through edge connectors. - Herb

"A common LM2 role was as a substitute for a ~$20,000 Honeywell analog data tape recorder with obviously much additional capability; Especially for data analysis where it supplanted oscilloscope photography and hard-wired signal averaging equipment for instance."

- Charlie Garthwaite, from a number of email interviews

Backgound Notes

Dr. Kehl and Dr. Torode both have a long and substantive history in digital design and development, in developing companies, and in training other leaders and designers of computing technology. Their early work was at the U of Wash. Charlie took some time to detail to me, some of the activities there in the early 1970's, and some subsequent work by Kehl. - Herb Johnson

Packard-Bell and Raytheon computers

"The Physiology & Biophysics Dept. had 3 of the Packard Bell 440 which later became Raytheon 520 midi-computers; Other sites of the era included Rolls-Royce jet engine test bed in UK [Bristol ?] and NASA Houston orbital calculation with a ring of several 440/520s."

"We had an active parts and technique exchange. E.g. UoWA contributed technique for replacing germanium with silicon transistors, replacing the 'grain o wheat' incandescent register-bit lamps with LEDs, an interface to replace the IBM Selectric console with a TI Silent Writer after IBM begged out of a perpetually renewable service contract. I believe they gave us a grant for the development. Amazing what one remembers!"

Charlie provided a Web link to a Packard Bell 440 description at the Web site as linked. The content is from the report "A FOURTH SURVEY OF DOMESTIC ELECTRONIC DIGITAL COMPUTING SYSTEMS" by Martin H. Weik. BRL REPORT NO. 1227, JANUARY 1964, ABERDEEN PROVING GROUND, MARYLAND. "BRL" is the Ballistic Research Laboratories at Aberdeen. The Web site is operated by Ed Thelen, the paper original is apparently at the Computer History Museum. - Herb

"Various departments at UoWA [had 700-series Raytheon systems]. PBio had a number of machines. A 703 built by Raytheon using wire-wrap boards [was] in a very substantial 19" rack cabinet. Several 704s which had PCB technology housed in 'desktop' box about 18" on 3 sides. 2-3 706 machines were USAF military surplus via NIMH. One in particular arrived with a bullet hole in the cabinet and a scrap of teletype roll with hand scrawled note "Goodbye Cyprus". 706's had ASR-35 Teletype units."

"On visits to Raytheon factories in Santa Ana, CA (a former Packard-Bell plant) and in Norwood, MA, I saw fully-automated Gardner-Denver wire-wrap equipment building ~18"x24" boards that filled tray-like drawers in subtantial custom 19" rack cabinets. The Raytheon 703 & 706 mini-computers were constructed that way. Many of these systems were incorporated into DoDefense projects developed by Raytheon. They also were used for geo-physical studies with a Raytheon built hardwired Array Transform Processor co-processor."

"The brothers Lowell & Gene Amdahl figured in the hardware design of the Packard-Bell 440, SDS Sigma 9, IBM 360, and later the Amdahl mainframe."

- Charlie

LINC and LM2

Below is an exerpt on "Early Computerization" from "The Department of Physiology and Biophysics, University of Washington School of Medicine, A Brief History 1946-2010" By Marjorie E. Anderson, PhD (as based on a prior history by Allen M. Scher, PhD). Obtained at the linked Web page as suggested by Charlie Garthwaite - Herb]

The departmental faculty realized early that direct input of data into a computer was an important step in advancing quantitative research. Analog-to-digital (A-D) converters were built by Dr. Allan Young and Edmund Brand, as described in the 1961-62 annual report (pg 10). These could be used to transform information from recording instruments to a digital form that could be fed into the University's IBM 709 computer. A computer-based A-D system for the department had been funded by 1962, and Dr. Ted Kehl was appointed to the faculty to train students and postdoctoral fellows in the programming and other techniques necessary for computer-based quantitative physiological analysis. Drs. Woodbury and Gordon participated in the LINC evaluation program, which was sponsored by NIH.

For many years the LINC was the main computer for training graduate students because it was simple, useful, user friendly and easy to to program in machine language. Kehl and his colleagues went on to develop an inexpensive dedicated laboratory computer called the LM2. This custom built laboratory computer became important in the research programs in a number of Pbio research labs including those of Drs. Berger, Hille, Scher and Albert Gordon. For quite a few years there was a required hands on course in which graduate students had to use the LINC. A workable program for performing some useful function was required for a passing grade.

A LINC computer was installed in Dr. Woodbury's lab by 1964, and by 1965, a Raytheon 440 computer to be used by the entire department and the Primate Center. In fact, Dr. Bertil Hille joined the departmental faculty in 1968 largely because he would have access to a computer with A-D capability. He could use the computer from Woodbury's lab all day long---on Saturdays. - [See reference above]

After the Logic Machine

from "Silicon Chips in the Pacific Northwest", a "Pathfinders" history on the University of Washington research Web site. Researched and Compiled by Deborah L. Illman at the university, further attributes on the Web site. From an exerpt recommended by Garthwaite.

"When asked by Boeing to teach engineers there, [pioneering large-scale integration designer] Carver Mead [asked] Ted Kehl to put together a joint UW/Boeing summer school on VLSI design with Mead as instructor. That first VLSI class in the Pacific Northwest, held during the summer of 1979, included UW faculty and students, Boeing engineers, and the original members of the Seattle-based Engineering Group [led by Dave Cutler] of computer manufacturer Digital Equipment Corporation....From that [success] came a collaborative research arrangement between industry, the university, and the government, called the University of Washington Northwest VLSI Consortium, established by Kehl and computer science chair Robert Ritchie, and aimed at research and education in VLSI technology. The consortium opened its doors in January of 1982."

The text states that those students and teachers were a "catalyst" in the Northwest in the subsequent period, producing products including the first MicroVAX by DEC; and the founding of companies like IC Designs in Seattle. - Herb

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Herb Johnson
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Copyright © 2012 Herb Johnson