35 Year-Old C64 Easter Egg Hidden on Vinyl [video]

Oh, no at all, distribution of software as audio was not exactly common but wasn't unusual either. In the Netherlands there was a radio programme that broadcast C64 programs you could record on cassette. Some printed computer magazines included software on flexi discs which were thin, flexible vinyl sheet records. Record players and double cassette decks, like the one in the the video, were ubiquitous back than. Double cassette decks were the means of choice for copying cassette software because this was much faster than on the computer. The Datasette was much cheaper than a 1541 floppy drive. Recording the audio from a record to tape and loading it via Datasette was a minor inconvenience compared to other methods of software distribution used back then.

The usual way to get new software, and with that I mean software you couldn't copy from your friends, was to just type it from a computer magazine. A considerable part of the old magazines was printed program code you could type in and run. I deliberately didn't write source code - it was raw hex listings. The typical form, if I remember correctly, was two columns with 17 hex pairs in each line. 16 bytes were program, one byte was a checksum. You would enter it in a program that would make an annoying buzzer sound when you hit enter at the end of the line and the checksum didn't match. The program I used was from a German computer magazine and aptly named checksummer, which is a nice wordplay on checksum and summer which is German for buzzer. So software on records was neither inconvenient nor expensive.

EDIT: Dug up an example:

https://www.retropoly.de/c64er/1988/64er_1988-05.pdf

One hex listing starts at page 42. Format is a little different from what I remembered, 8 bytes code plus 1 byte checksum, four columns of that on a magazine page.

I think they did it because they could, because it was fun. Because you could tell someone else you did it and they'd say "wow". But to get a wow these days takes a lot more!

Compact cassettes were used as a typical method for dictation for this time period. They were quite inexpensive even in the 1960s, let alone the 80s. I used to have a monaural battery tape recorder as a child with plenty of blank tapes in 1981, and was poor. This was not expensive stuff, less than a dollar per tape.

Further the group of people that would be in the market for a C64 or earlier tended to be more tech savvy then when PCs had mass adoption.

I think the “challenge” here is much more finding the track after the run out, especially with an auto return deck. Also while there are notable counter examples, Christian rock listeners is not exactly overlapping with the tech crowd in a large way. This was an obscure album.

If this had existed on a metal album it would have been found day 1, I guarantee it.

As to effort. Seems pretty simple. Record program to tape... put on master. This wasn’t any great feat of engineering.

C64's on the other hand, was much less common, but if someone had a cassette deck, a record player AND a C64, you can bet that he/she would have had a cassette player for the C64 as well.