I read a bit of the book when excerpts appeared in a magazine, then a bit later read a roommate's copy. Later still, after I had some experience with the MV/Eclipse line, my wife was assigned the book for a management class, and I read it yet again. A couple of points were clearer on that reading:
- The decision to incorporate the 16-bit instruction set imposed certain constraints. The MVs had four general-purpose registers, for example; for another, one could address words but not bytes with a register-relative address.
- The lead architect of the team had wanted a VAX-like instruction set. The VAX instruction set was elaborate, just the thing if one were writing an operating system in assembly language.
- About the time that the book came out, researchers in California were discovering how hard it was to speed up the VAX to the point they wanted, and considering alternatives. The new model of "reduced-instruction-set computing" (RISC) produced some startlingly fast machines, and ate into the old minicomputer market at the high end while the 386 started to nibble at the other.
I enjoyed working with the MV/8000 and its successors, and for that matter their 16-bit predecessors. The AOS/VS operating system did many things well, the command-line interpreters were well thought out, and the assembler easily enough learned. I'm grateful for the chance to have worked with those machines.