chip compatibility

Anton Sherwood (
Mon, 2 Feb 1998 19:41:35 -0800 (PST)

: Harvey Newstrom <> wrote:
: >Yes, backward compatibility is a sham. x86 chips are not compatible
: >with Pentium are not compatible with MMX, etc. Macs have the same
: >problem. The 86xxx motorola chips are not compatible with the PowerPC
: >chips. MacOS won't be compatible with Rhapsody.

Jeff Fabijanic writes
: Untrue. I have never encountered, nor have I ever heard of anyone
: who has encountered, a valid 680x0 (not 86xxx, btw) instruction
: that did not run correctly on a PPC chip (albeit in emulation).

For whatever it's worth, my old versions of Word (4) and Excel (3?)
bomb on my new PPC - illegal instruction. They being MS products,
I would not be surprised to learn they use undocumented instructions
which are not emulated.

Anton Sherwood *\\* +1 415 267 0685 *\\*