[nwellinghoff]

Amazing they didn’t just leave a space on the card for a jump operation of some sort. When you want to add something to your program or fix an error you just use the space to say “jump this many forward” and resume. I guess there is a good reason something like this was not possible?

[spiralx]

Probably not possible because it wasn't thought of when the system was first implemented and introducing such a change would involve getting new hardware with the jump feature and quite probably new hardware both to read the new card format and to produce the cards themselves. And everyone else also having to do so given the dominance of the IBM 12/80 card format.