On Sep 12, 2016, at 2:21 AM, Peter Corlett <ab...@cabal.org.uk> wrote: > > On Sun, Sep 11, 2016 at 06:43:32PM -0700, Chris Hanson wrote: >> This person was talking about 680x0-based Macs being “16-bit.” Ugh. > > The original 68000 *was*. Although there were instructions for 32 bit ALU > operations, it only had a 16 bit ALU and the operands had to go through the > ALU > twice. This illusion went away with multiplication and division, which only > existed in 16 bit form. > > The 68020 onwards made the CPU fully 32 bit, although various bits of legacy > 16 > bit cruft remained for compatibility.
No, the 68000 was a 32-bit CPU, as defined by the register width and programming model. The fact that it was implemented with a 16-bit ALU and had a 16-bit data path to memory is immaterial. -- Chris
