[edit] I had written the response below before I noticed that other folks had already replied with similar stories. [/edit] trønderen wrote: I guess that source code files were stored as plain text, using the selected set of word symbols, right? So you couldn't take your source file to another machine, with other concrete mappings, and have it compiled there. That is correct - the source code was hand punched onto cards (80 column). I got quite adept with the multi-fingering buttons for each character. You then put the box of punched cards into a holding area where someone would feed them to the card reader (hopefully without dropping them and random sorting them). Then the job was run and you got a line printer listing delivered to the same holding area (where, hopefully, your card deck was also returned to) - this is the first time that you can see what the texts were that you had written. At University, the turn round time was 1/2 a day; at my first full time job it was nearer a fortnight; so computer run times were an insignificant part of the round-trip time. Before Uni, I had to do coding sheets which were posted to the computer centre (round trip one or two weeks). This added an extra layer of jeopardy - would the cards be punched with the texts written on the coding sheets? The answer was almost invariably 'No' for at least three iterations; so the first run (enabling debugging) could be six weeks later than the date that you wrote the program.