Magnetic Tape Drives

IBM mainframe 9-track tape drives, model 3420 attached to 3803 control units, in the Columbia Computer Center machine room, 1982.

DECSYSTEM-20 9-track tape drives, model TU77, in the Columbia Computer Center machine room, 1982, and the four hardcopy (LA36 or LA120) operator consoles for our four DEC-20s, CU20A-D. The TU-77 was the 1600/6250 bpi autoloading drive that replaced our earlier 800/1600 bpi manual loading TU-45s. They were used back up the DEC-20 file system (including more than 6000 user IDs), for mountable offline storage for big datasets, and for writing Kermit software tapes for export.

A portion of the Columbia Computer Center tape library. What you can't see in this view is how the rack in the center is at the head of a long row of racks just like it.

Photos: Bob Resnikoff.