[pedroaniceto]

Yes, a single variable notification in code, could cost THOUSANDS just because someone would punch ONE card with the new data, compile it (with no errors), save it on a cassete tape, (write the label of the tape with a new version number) and deliver it to the customer. There were no monitors. Computers would have a "BOITIER" (a rectangular box of coloured lamps) who coould have 3 meanings, ON, OFF and BLINKING. We're talking about 16 light points, and the interpretation of those lights would have the answer for the completed action. 3 whites and 3 reds would mean "No errors on compiling". But that action only verified syntax. Logic was another department :)

[thih9]

Mind blowing. 50 years later we are putting VM in a VM in a VM to send videos of funny cats along with bank transactions across the world to everyone’s wireless pocket computer.