Sorry to continue the detour from disk file systems to card trays, but this
Walking down the corridors of Comp Sci, a student in
front of me
dropped his entire deck of approx 2000 cards, all over the floor...
I have no idea whether he got them sorted, but I sure as hell used
rubber bands after that!
reminded me that Vic Vyssotsky liked to say of his BLODI (block diagram)
language for simulating sample-data systems that it was the only card-safe
language. You could toss a program deck down the stairs, pick it up at the
bottom, submit it to the compiler, and it would work. That was 10 years
before the filing of the famous "natural order" patent on spreadsheets,
which ordered execution the same way.