My colleague and I have just had a conversation and we were wondering how the process of developing an application was done in the era of cassette tapes.
Today we have HDDs, backup HDDs, FTPs, repositories in the cloud, etc. -- so we don't care: we just save, send and share our data, but...
I myself, as a child, had a Timex 2048 (ZX Spectrum clone) in the 90s and I remember that creating an application involved saving my work on the tape, then next day I loaded it into Timex's memory, made changes, saved on the tape again and so on. But I worked alone for my own happiness and the applications I created weren't complex.
But what about cases when there were two or more developers? How did they share their code?
What about complex applications? Graphics (simple, but still) for games?
What about the durability of their work? We all know that cassette tapes were very unreliable: errors during saving and reloading data were common. (Eventually FDDs became available for computers such as Spectrum, Atari and Commodore, but as far as I remember they were quite expensive; and they weren't available from the very first moment, were they?)