The Early Days with Dr. Glen Culler

Ray Bjorkman

I met Glen Culler in the early 1960's at TRW in Canoga Park standing in front of the computer panel of the RW-400, a huge computing system designed by TRW for the Air Force. Glen was editing a program in machine language coded in octal, laboriously entered in binary using 28 rocker switches -- one for each bit in the instruction. Glen played this panel like a maestro pianist, his fingers flying. Glen was consulting for UCSB. My job at TRW was to maintain the RW-400.

The RW-400 was a huge system, consisting of about 30 bays of equipment connected by cables through a huge (6 bay) cross-bar switch, using magnetic technology. The RW-400 CPU contained four bays of equipment with a total instruction memory of 1K-28 bit instructions. Driven by a vacuum tube, it ran at a clock rate of 167 KHz. Integrated circuits had not been invented, so the rest of the computer was constructed using discrete transistors, diodes, and resistors. Programs were entered on paper tape made on a flexowriter. The only I/O device, initially a card reader, was added later. The basic component of a computer, the flip-flop, was contained on a 4"x6" card. A typical register rack required 26 such cards -- my how things have changed!

Glen is a master at getting the most out of any equipment by working around malfunctioning parts. During one memorable demonstration for the Air Force, a storage drum was having trouble reading a few bad tracks. The whole system appeared to be broken. Glen came in and ran his on-line program using the same equipment, but avoiding the bad tracks on the drum. Every system ran flawlessly, saving the day for TRW.

TRW was late in delivering the RW-400 system, so in 1966 the Air Force canceled the contract. I was out of a job and TRW had a computer that they had no use for. They donated the RW-400 CPU to UCSB. This provided a tax write-off for TRW and allowed Glen to continue developing his on-line system. I hid in the cabinet and came to Santa Barbara as part of the deal. My job was, again, to maintain the system.

Our first task was to get the RW-400 into the computer center in UCSB's North Hall. The doorways were too short so we took out the windows and moved it in that way.

Once the system was up and running, Glen worked with BBN and Tektronix to develop an individual workstation. They combined a Tektronix storage oscilloscope and a modified Microswitch keyboard to produce a functional workstation.

Glen Culler may well be the Father of On-Line Interactive Computing. Classrooms at UCSB were set up in the engineering building, as well as in the Physics, Chemistry, and Psychology departments. Using telephone service, they were connected to a classroom on the UCLA campus. As far as I know, this was the first ever use of on-line interactive computing. Today this is accomplished by placing a PC in front of each student.

The biggest problems encountered in the classrooms around UCSB campus were from malfunctioning Microswitch keyboards. This prompted Glen to design his own keyboard using a unique switch with a magnetic break-away, which provided excellent feedback to the user. The design was terrific, truly a stroke of genius. The contacts, however, were not hermetically sealed so implementation was unreliable. After considerable effort, the project was dropped. Fortunately, Microswitch came out with a new keyboard using Hall effect switches which eliminated the problems.

The completion of the new Engineering building on campus brought with it a decision to move the RW-400 CPU to the third floor of the new building. This time the elevators weren't tall enough. The solution was to remove the horizontal windows and attach steel I-beams going straight outside. A crane lifted the CPU up three stories, laid it on its back on the I-beams and slid it in. This was terrifying to watch but it worked.

The riots and bank burning in I.V. and the militant takeover of the computer center in North Hall, convinced Glen, who dislikes violence, to accept an offer to become director of the Computer Research Department at the University of Washington. Glen sent Mike McCammon ahead, as the advanced guard. When Glen asked me to go, I politely had to refuse. After moving to Santa Barbara and buying a home, I wasn't about to move again. So when Glen asked me if, instead, I would go with him to start his own company. I said "sure."

With a little financial help from Dean Harrison, Glen founded Culler-Harrison Inc. (CHI) on April 1, 1969. The first site was located on Ward Memorial Blvd.

A new company starting out needs furniture, but instead of buying it as any normal company would do, Glen designed the desks and bookcases. All of the employees got together and built his or her own desk and bookcase. I will never forget how skillful Glen was a manipulating a belt sander. Every time I tried, I ended up plowing ruts into the surface. The desks were a unique design, with a tilting top that converted into a drafting table. I still have mine.

Our first product was to be a speech analyzer/synthesizer -- an enormous task. My first design task was, I thought, to build a controller but it turned into a mainframe computer. In fact just about everything I designed for Glen seemed to end up as a computer.

The first one, called the MP, was so unique that Glen was awarded a patent for its parallel architecture. Four independent fields in the instruction were used to perform four independent operations simultaneously in a single clock period of 125 nano-seconds -- fast for its day. Thus, the clock rate of 8 MHz was also the instruction rate.

Everything I designed for Glen had to run as fast as possible. From that day to this I have been counting nano-seconds. As a result, I acquired the title "Dr. Clock." If I were still designing for Glen today, I'm sure I would be counting pico-seconds.

Before the rest of the world had heard about digital recording, we were developing speech research digital recording techniques using a large Calcomp disk drive. One day a violinist from UCSB came by with his Stradivarius and had us record a few passages. To this day, I have never heard a more realistic violin recording.

The Rogers Organ Company contracted us to synthesize a large pipe organ -- an interesting project that produced some very realistic sounds.

A memory chip company hired us to synthesize small messages stored in memory. "The white zone is for the loading and unloading of passengers only," was one of the phrases we got real sick of hearing.

Glen is the most creative system architect that I have ever met. He gets maximum performance out of any given technology by what I like to call "architectural cleverness," rather than just relying on existing technological advances to improve performance.

If Glen has any faults, it's that he never learned how to relax. He has been known to take a clipboard with him on a vacation to Hawaii and to take it down on the beach to solve a problem or design something.

Glen Culler has inspired the careers of many of his students and co-workers with his dynamic personality, his tremendous source of knowledge, and his trust in intuition. Most important, his faith in their abilities and his own example has given them confidence that they can accomplish anything they set their minds to.

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