On Sat, Apr 9, 2022 at 2:29 PM Ken Thompson <kenbob@gmail.com> wrote:

vic was my department head upon my arrival at
bell labs (june 1966). i went to my assigned office
and found vic, in combat boots, in a lotus position
on top of my filing cabinet. it is a vision that i will
never forget. he had just come to introduce himself.

This is a great story, though I confess that the thought of sitting like that sounds rather uncomfortable.

I wonder if either or both of you, Ken, and Doug, could talk a little about the Bell Labs withdrawal from Multics from your perspectives? What was that like, and what was your relationship with the folks at MIT still at Project MAC like afterwards? I gather it was friendly; was there any collaboration there beyond casual correspondence?

- Dan C.

On Sat, Apr 9, 2022 at 4:48 AM Douglas McIlroy <douglas.mcilroy@dartmouth.edu> wrote:
> Single Level Storage is an awesome concept and removes so many ugly
> hacks from algorithms that otherwise have to process data in files.

This was Vic Vyssotsky's signature contribution to Multics, though in typical
Vyssotsky fashion he never sought personal credit for it. Other awesome
Vyssotsky inventions:

BLODI (block diagram), the first data-flow language, for sample-data systems.

Parallel flow analysis (later reinvented and published by John Cocke). Vic
installed this in Fortran to produce diagnostics such as, "If the
third branch of IF
statement 15 is ever taken, then variable E will be used before being set".

Darwin, the original game of predation and self-reproduction among programs.
Corewars.org keeps a descendant version going 60 years later.

A minimum-spanning-tree algorithm quite different from the well-known methods
due to his colleagues Bob Prim and Joe Kruskal, again unpublished.

Not long ago on TUHS, Andrew Hume told how Vic found the same isolated bug in
dc by mathematically generating hard cases that Andrew stumbled on by accident,

As you may infer, Vic is one of my personal computing heroes.

Doug