Plane of core memory

[Noel Chiappa]

    > 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.