David Strom writes:
''Back in the early days of DOS, we had a memory barrier of 640kB of memory.
I know, it seems quaint now, something that you can find on the chipsets of audio greeting cards rather than real computers, but we spent a lot of time juggling applications to fit in that space. We had special hardware cards that could address more memory, and we had swapping programs (remember Quarterdeck?) that could allow us to run bigger apps. (And for those of us who are really old, we even remember the 64kB barrier of the earliest Apple // computers!)''