Not sure I understand the point of a 24-bit cpu. If 16b-wide registers don't cut it, the difference between 24 or 32 bit wide registers can't be that much in te

Not sure I understand the point of a 24-bit cpu. If 16b-wide registers don't cut it, the difference between 24 or 32 bit wide registers can't be that much in terms of transistors or cost, right? You can have address lines for say, 20..24 bit wide memory (1MB & up), but still have a full 32 bit architecture internally. Or (if lowest cost/power is desired) the other way around: a 16-bit cpu with >16 external address lines, handled by built in MMU. On the R800: this is indeed a nice chip. ASCII developed it for the MSX Turbo-R, but (afaik) never bothered to put it on the market for use elsewhere. Don't think I've ever seen a datasheet of it, either.