The most dispiriting day of my childhood was when I discovered that the write connection to the tape deck on my Spectrum +2a had failed and the day's worth of code I'd written had been lost and I had a blank tape.
heh. I fortunately did not know things like assemblers existed. I hand-assembled my assembly to machine code using the mnemonic table provided at the end of the programming manual. I had an entire diary full of columns of hand-encoded hex numbers (and a decimal column - you needed the numbers in decimal to "poke" them into RAM).
But your soul dies slowly as you have to reload your program from tape cassette. I remember learning machine code on my Spectrum and having to reload the assembler several times an hour.