—The Cray 1 Supercomputer: Computing in the Good Old Days

Cray 1-2116


The photo is of a Cray-1 from the Smithsonian Air&Space Museum in Washington, D.C. [Maybe I’ll get around to posting some of the aircraft later] They used to call these “supercomputers”.  This one, use for early weather modeling and atmospheric research, was a 64-bit machine, and had a mind-boggling 1 megabyte of memory! The memory, and the liquid freon cooling system it required to operate are no longer with it.  The rat’s nest in the middle of the trademark cylindrical shape of the Cray is what we old people used to call “wire wrap” connections (I still have two of the tools used to make wrapped connections on little square posts).  Another display says that because of the circular shape, although there are “over 60 miles of wire in the Cray”, no connection is more than 2 feet long. 

If the Cray-1’s processor was fully “hard-wired”, as opposed to the micro-coded CPU’s we use now, this thing is even more mind-boggling.  Try to imagine the patience needed to hand-wire all those connections, squinting at some telephone-book-sized wiring diagram.  Then try to imagine how one would correct a mistake later.  One of Cray’s earlier machines was so complex that it basically couldn’t be kept running. 

Granted that many peripherals probably have this much computing power today, and air cooling generally suffices unless you’re a die-hard FPS’er, but it’s good to consider how we got to the incredible little boxes of computing power under our desks.  Our personal computers represent a lot of very expensive lessons, many learned the hard way. 

I think Texas A&M still has the horrible old Amdahl in the basement of its engineering building that I had to punch cards for in 1979.  The past isn’t as distant as you may think.


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