Data Centers

Dinosaur Sightings: IBM 5251, 4000 Series VAX, Timex Sinclair and more

IBM System/360 Model 75 console

Wilf Mandel submitted this great picture of the console of an IBM System/360 Model 75. Wilf wrote:

?"The picture was taken in the computer room at McGill University, back in the 1970's. This machine replaced our "old" Model 75, after its retirement from the NASA Apollo program. Cycle time was 750 nanoseconds; it had 512K of core storage.

?"We also had 1 megabyte of "Large Core Storage", which had a slower cycle time (such that it couldn't keep up with our 'high speed drum'). It ran OS/360 MVT with HASP (non-virtual operating system). The toggle keys were used to enter data in to core storage (each 8-bit byte had 2 sets of 4 white data keys and a black parity key), and could also be used to enter machine language code.

?"That?s right, 512K (vs the 512Meg and up on a PC)! And the memory was made up of those little ferrite rings called 'cores' with read/write/reset wires strung through them. Oh yes, the lights--you could tell what the machine was doing by looking at them. Impossible on modern mainframes because processing is too fast to have lights keep up.

?'It's mind boggling that a PC's are now more powerful than this machine that was used in the space program that took us to the moon and back."

Photo by Wilf Mandel

Submitted by Wilf Mandel

About Bill Detwiler

Bill Detwiler is Managing Editor of TechRepublic and Tech Pro Research and the host of Cracking Open, CNET and TechRepublic's popular online show. Prior to joining TechRepublic in 2000, Bill was an IT manager, database administrator, and desktop supp...

Free Newsletters, In your Inbox