[carapace]

So well put! I bow.

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FWIW, when I was poking around last night looking for references for the "forced to get a Mac" story I found this.

Tony Hoare:

> The first time I visited Edsger in Eindhoven was in the early Seventies. My purpose was to find out more about the THE operating system, [Dijkstra, May 1968.] which Edsger had designed. In the computing center at which the system was running I asked whether there was really no possibility of deadlock. "Let's see" was the answer. They then input a program with an infinite recursion. After a while, a request appeared at the operator's console for more storage to be allocated to the program, and this was granted. At the same time they put a circular paper tape loop into one of the tape readers, and this was immediately read into buffer file by the spooling demon. After a while the reader stopped; but the operator typed a message forcing the spooler to continue reading. At the same time even more storage was allocated to the recursive program. After an interval in which the operator repeatedly forced further foolish storage allocations, the system finally ground to a complete halt, and a brief message explained that storage was exhausted and requested the operator to restart operations.

> So the answer was YES; the system did have a possibility of deadlock. But what interested me was that the restart message and the program that printed it were permanently resident in expensive core storage, so that it would be available even when the paging store and input/output utilities were inoperative. And secondly, that this was the very first time it had happened. I concluded that the THE operating system had been designed by a practical engineer of high genius. Having conducted the most fundamental and far-reaching research into deadlock and its avoidance, he nevertheless allocated scarce resources to ensure that if anything went wrong, it would be recognized and rectified. And finally, of course, nothing actually ever did go wrong, except as a demonstration to an inquisitive visitor.

https://history.computer.org/pioneers/dijkstra.html