Hmm. "Cards" is probably the wrong word: they're actually pieces of paper, they're just the same size as record cards so I can put them in record card boxes. Here's one of the oldest:
As you can see, it's printed on old-time green screen lineprinter paper. This probably dates from about 1980. I started writing the cards by hand, but because I wanted two cards per recording (one for piece title, one for composer) it rapidly grew tedious. It was also irritating having to write the same source multiple times for when there was one casette tape (that's how my music came in those days) with multiple pieces on it. I therefore wrote a program to enable me to enter the data quickly, which printed out as many "cards" as I needed. If it had two or more titles, I'd print a card per title; if it had two or more composers, I'd print a card per composer. It put all the text into a large array so I could print it on a monospace printer (which is all we had back then) with maybe 20 cards or more per sheet, so as not to waste paper. I then cut the cards out using scissors and put them in the right record card box: red for indexed-by-composer, blue for indexed-by-title.
This worked well enough until someone decided that printing off my music collection records was a misuse of computer resources, so I rewrote the code and ran it on my office PC using my office printer. That worked well enough, too, until I left the university and had to rewrite it again for my Apricot F10 home desktop computer. When I had to give that up for a PC, I rewrote it yet again.
As a result of this, I have four boxes of paper index records printed using perhaps six different printers. The format is the same for all, but they were written using one of four different incarnations of the software, each written from scratch. I must have spent hours and hours typing in all the details.
Nowadays, all my music is on iTunes (assuming Apple hasn't evaporated it without telling me). I do still have the tapes, but few of them play very well. The ones that I tried to import to my PC came overlayed with an annoying pulsating sound emanating from some RF interference of unknown origin, so I rarely listen to them.
The last time I looked at the index records must have been about 5 years ago; the time before that, probably another 5 years earlier.
Off to the recycling bin they go...