Emulating
That's not as hard as you think, but perhaps the terminology being used
is confusing: "Translating" Intel-to-Moto is what PC-Task does; it sits
there and looks at every line of x86 code coming in and outputs the proper
lines of 68K code, and this is why it's so slow.
SoftPC, however, which Jerry mentioned for the Mac and is also avail-
able for Unix, actually recreates the functionality of the x86 chip in RAM
as a "device file", which is in the literal sense a "translator" but in a
run-time sense is the actual Intel chip, with all the necessary registers,
pipelines, instruction processors, and so on. Provided the proper kind of
memory-chips (some sort of EEPROM, I would guess) are installed on the
Emplant, there is no logical reason why anything up to a 486 can't be
directly re-created as a "process" (the Pentium's speed would be hard to
duplicate, but not its instruction-set).
Remember: 80×86's are stupid chips, which have been kept stupid because
of the need for "backwards compatibility" with the 8088 (which is where
the original instruction-set comes from); however, historically they were
always cheaper than the memory-chips it would have taken to emulate them
(which is why C= and other built Bridgeboards).
Mr. C (Amiga: Muerte O Suerte?)