> From: Curious Marc
> I believe 3 wire memory was first introduced by IBM in their 360
> systems ... They would almost certainly have patented their way to do it
Correct (and your knowledge and memory is good)! Motivated by this clue, I
looked in:
Emerson W. Pugh, "Memories That Shaped an Industry"
MIT Press, Cambridge, 1984
where the description of the invention of 3-wire core can be found on pg.
231; it was invented by a group of engineers, based on a similar idea used in
Stretch. There is indeed a patent, No. 3,381,282, with six names on it. IBM
must have licensed it, but there is nothing on that.
I can highly recommend that book; it's in the same league as the later two
books on early IBM computers from MIT Press on which he was a co-author.
Noel
PS: There was recent discussion here of the 8000 series; there are some
details on that on pp. 189-191.
