Mixsonian Larry

The Mainframe

The University got a discount on IBM computers, so they had the largest model IBM made at the time an IBM 360.  It had a whopping 1 megabyte of core memory, in comparison my phone today has 256 G, 250 thousand times more than the IBM mainframe at the time.  Ok, geek history lesson here: The IBM 360 had core memory, with a core being a small metal ring the size of a pin head that had four wires running though it and arranged in a grid.  From electrical current running though the wires, the core could be magnetized off and on to represent 0’s and 1’s in binary, the language of computers.   For those non-geeks, cores were like brain cells storing memory.  Think of the scale, one million, pin head sized metal rings with wires running though each, mounted in frames like a quilt in a quilt rack rows and rows of them taking up a cabinet the size of three refrigerators.  Today technology has advance so that we can fit 256 gigabytes on a chip smaller than just one of the cores in the IBM memory.

While the mainframe was the size of three refrigerators, there were a dozen mores single and double  refrigerator sized cabinets in the computer room, controllers, printer, card reader, card punch, tape drives, disk drives, all in IBM blue and white cabinets.  One winter day I followed one of the full time operators in to work when, instead of going to the mainframe console, he went over to one of the cabinets in the back, opened up one of the side panels that was on hinges, reached in and pulled out a coat hanger, put his coat on it and hung it in the cabinet.  The unit was only half full, he explained, leaving room for future expansion.   Later, over a weekend, IBM removed the Model 360 and installed the newer model 370.  

IBM 1401 Computer