Timesharing is a computational technique where multiple users, on multiple terminals, share access to the resources of a single computer system. In practice, the central processing unit affords each user a "slice" of time measured in fractions of a second to give the appearance that multiple users have simultaneous and exclusive access to the system. At Edinboro State College, in the early 1980's, there were perhaps two-dozen terminals open to student access -- each giving interactive users the impression that they were the sole operator of the system.

When I first started using the UNIVAC 90/60 the typical terminal was a Teletype Model 33 ASR with built-in paper-tape punch and reader. These were soon upgraded to the Teletype Model 43 which, although it lacked the ability to punch and read paper tape, ran at more than three times the speed of the Model 33 and printed using a dot-matrix print-head. There were a smattering of other terminals in use, including a few DECWRITER teleprinters, ADM-3A CRT's, and (very few) UNISCOPE CRT Terminals.

The interactive nature of time-sharing made online text editing a much quicker process than keypunching your program on cards. Likewise, the cycle of edit-compile-debug went much more quickly when you had immediate feedback from the system. BASIC was the language of choice for time-sharing, where one could sit at a teletype and interactively enter, edit, and debug a program in "real time." FASTFOR was an interpreted version of the FORTRAN programming language that allowed one the same interactive experience as using BASIC. Programs in other compiled languages could be entered and edited using the online text editor, even though COBOL and RPG were still primarily oriented towards batch processing.