Where the 360 crushed home computers was in mass storage
Well...sure, you could put bigger storage on a mainframe. It's just money, after all. But you could put a tape drive on a home computer. And bigger disks. And a card reader, for that matter. Where the 360 really crushed the home computer was in aggregate bandwidth, via the Channel architecture. An Apple 2 could just about keep up with a floppy and a display. A 360 could keep up with dozens to hundreds of tapes, disks, card readers, terminals, printers and other things all at the same time.
Large storage compared to memory meant a lot of focus on external memory algorithms
I would agree with that. I would just argue the real mainframe advantage is a whole-system one and not point to a single factor (memory size).
Well...sure, you could put bigger storage on a mainframe. It's just money, after all. But you could put a tape drive on a home computer. And bigger disks. And a card reader, for that matter. Where the 360 really crushed the home computer was in aggregate bandwidth, via the Channel architecture. An Apple 2 could just about keep up with a floppy and a display. A 360 could keep up with dozens to hundreds of tapes, disks, card readers, terminals, printers and other things all at the same time.
Large storage compared to memory meant a lot of focus on external memory algorithms
I would agree with that. I would just argue the real mainframe advantage is a whole-system one and not point to a single factor (memory size).