This would have been assembly code, probably 6809 or 68000 system I had back then. 6809 would have required dumping intermediate data to a disk. I don't recall just when I first got a hard-disk, which would probably have been a massive 10 megabytes in size.
And yes, I saw that transition. I learned to program using Fortran IV and IBM 11/30 assembly in the mid-70s, using punched cards. Wrote a MIXAL assembler and simulator for the minicomputer at the local college around 1976; it was about 7000 punched cards in length, all assembly. Got a Commodore PET in 1978, moved on to SS-50 based 6809 and 68008 systems in the late 70s/early 80s, with a serial terminal.
You just reminded me of when I bought my first PC in 1990 and one of my former professors, on learning I had bought it with a 200MB hard drive declared that I was crazy to buy such a large hard drive because I would never fill it up.¹
One of my more embarrassing memories (technical ones, anyway) was having an argument with a couple of friends in college in 1988/89. I felt that sure, an internal hard drive is a nice feature, but swapping floppies wasn't all that terrible.
You could have made a significant amount of money betting against my technical predictions over the last few decades.
And yes, I saw that transition. I learned to program using Fortran IV and IBM 11/30 assembly in the mid-70s, using punched cards. Wrote a MIXAL assembler and simulator for the minicomputer at the local college around 1976; it was about 7000 punched cards in length, all assembly. Got a Commodore PET in 1978, moved on to SS-50 based 6809 and 68008 systems in the late 70s/early 80s, with a serial terminal.