Comment: Re:Everyone ignores Commodore (Score 1) 301
On the C64 you had to move the ROM out of the way to get to the RAM underneath. I don't remember the exact details but you could either see the RAM or the ROM and it was controllable.
If you want to get into memory expanders the C64 had at least a 512K ram expander available. I remember having one and it worked with GEOS at least.. might have been used as a form of ram drive to speed up games as well.
The drive drive was a computer in itself that you could buy ram expanders for and run programs on. Typically used for increasing load speed or duplicating copy protected disks.