On my punch cards they did. Every card had a number sequential to
sequence. The punch we used inserted them automatically. Well, the
programming card did. The reference number used for calls may have been
different, but I don't remember it.
Our programs were HUGE, multiple trays. Each tray was denoted by the
color of the diagonal line. We had 8 colors, so I guess we never had
more than 8 trays, because I don't remember pairs of lines anywhere.
Was the number actually punched in the card, or was it only printed
on the top of the card? Printed on the top of the card would not
require any modification of the card reader routine, and would not
eat up columns on the punch card. If I remember correctly, you only
If the number was punched, I could picture a program that would
re-order the program based on the number, if the cards were messed
up, but you would probably have needed a mini-computer to do that,
and feed it to the mainframe.
A: Because it messes up the order in which people normally read text.
Q: Why is top-posting a bad thing?