[TUHS] Re: PC/IP

On 5/1/25 12:20 AM, Al Kossow wrote: Some background, though the MIT LCS progress reports should cover much of this. I won't attempt to put any dates. Chris Terman was one of the graduate students in the RTS group. Since VT-52 terminals were relatively scarce, he designed and built his own with a larger screen - something like 40 lines by maybe 120 or 132 characters, called the "Termanal". I don't remember if it used an 8080 to handle the control sequences in the data stream or something else. He then got interested in designing a terminal that could display bit map graphics, to be comparable to the graphics used on the Lisp Machines just being built by the MIT-AI lab. I had stumbled across one of the LCS progress reports that credits Professor Steve Ward and one of the undergraduate staff, Rae McClellan in assisting the design of this bit graph which was named the "Nu Terminal" (I don't think it was the "Nu Termanal"). This used an 8086. A couple of these were built. One of the undergraduate students, Jon Sieber, had been a member of an Explorer Post in Murray Hill where Dennis Ritchie was the advisor. Jon would regularly bring UNIX tapes from the Research Lab and included things like early versions of the Portable C Compiler and the Circuit Design Aids. Chris used the Circuit Design Aids to design wire-wrap boards for the Nu Terminal and the RTS lab got a semi-automatic wire wrap machine. Some students and staff took turns doing the actual wire wrapping. My contribution was writing some simple software that simulated a paper tape reader for the wire wrap machine. An undergraduate student, Mike Patrick, did his bachelor's thesis writing a table driven assembler and constructed tables for the 8086 and I think an 8080. Later there were drivers for the Zylog Z8000, the National Semiconductor NS16000 and the Motorola 68000. I contributed a small bit of code for doing optimal choice of short vs long branches (to branch to an address more than +/- 127 bytes, you had to branch around a longer jump instruction). Chris Terman did the work of modifying the Portable C Compiler to generate code for the 8086, the Z8000, NS16000 and MC68000. I think we may have built one machine with the Z8000, but quickly settled on using the MC68000, primarily because of the 32-bit support (one progress report says that Zenith was supposed to build multiple Z8000 based machines, but I don't remember those. The NS16000 had better memory management, but I don't think we ever actually received any CPU chips. Anyway, these compilers were what was distributed, and the MC68000 compiler in particular was used by almost all the companies that came out the MC68000-based Unix machines. Apollo was a notable exception, but Apollo wrote their own operating system from scratch rather than Unix. Side note: Bill Poduska came to visit Steve Ward and before the visit Steve was all excited, but was disappointed that Bill was not going to use Unix. Before the RTS group used Unix, they had written a small timesharing system for the PDP-11/45 that was used in the 6.031 introductory computer science course taught by Mike Dertouzos. Chris was involved in maintaining that, though I think Steve Ward was probably the main implementor. Chris had also spent too many hours changing address jumpers on Unibus and other controllers as well as tweaking Unix mkconf files, and thought that while the 4BSD autoconfiguration was an improvement, there should be a better way. Chris and Steve designed the Nu bus, and the Nu Bus was used in the MC68000 boards. Eventually it was picked up by Apple. Chris was one of many students who took the Mead/Conway LSI design course and ended up abandoning his research on portable compilers in favor of simulating LSI designs. He was also a co-founder of Symbolics and designed the controller for their laser printer before returning to MIT as a Lecturer and sponsored research staff. There were also proposed follow-on software projects related to the Nu terminal. One was Trix. Steve Ward said he didn't know what an "ics" was, but Multics clearly had too many, and Unix had too few, hence Trix. Jack Test was hired to do a lot of the development. Wikipedia has a reasonable summary of Trix, as far as I remember, but I had left RTS to join Masscomp in late 1981/early 1982, and I know Jack Test was an early employee of Alliant Computer so he left Trix probably in 1982.