The code was COBOL. You programmed on a green-screen terminal, or a gold-screen one if you got a newer model. You earned your pay at night, when a program ble

The code was COBOL. You programmed on a green-screen terminal, or a gold-screen one if you got a newer model. You earned your pay at night, when a program blew up. The mainframe would provide a core dump, which was printed out on hundreds of pages of 'green bar' paper by the operator. You would go to the source library for an equally gigantic (like 900 pages) of program listing to find the source of the problem. This was accomplished with some hex reading and an IBM card that explained computer instructions and arguments. 'Networking' was always SNA and always secure. TCP was a few years ahead. C was available on the mainframe a little later. Linux on the mainframe likewise happened soon after, too. You mastered your application domain by dragging paper listings home to read frequently. Hot shot programmers may write 'online' programs (CICS), Assembly-language modules (for speed), or maybe do 'systems programming' (mainframe system admin). It all seems pretty ok now. Probably it wouldn't be fun to go back to it, though.