In article <kKCdnXMGZogpR_XZRVn-qw@comcast.com>, "Michael J. Mahon" <mjmahon@aol.com> wrote: > My mistake--from this chip photo, I incorrectly identified either > the registers or the ALU as a PLA: > > http://micro.magnet.fsu.edu/chipshots/mos/6502large.html See that mess of spaghetti in the middle? I think that's the instruction decoder.