68K Macs with MacOS 7.5 still in production use...

Peter Corlett abuse at cabal.org.uk
Mon Sep 12 04:21:43 CDT 2016

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.

More information about the cctalk mailing list