recursive emulation (was: IBM 7074 and then some: "Systems we love" conference)

[Jecel Assumpcao Jr.]

Chuck Guzis asked on Mon, 23 Jan 2017 22:00:15 -0800
> Is there a "recursive" emulator setup wherein one machine emulates
> another one...where the final emulation is for the original hardware?

In 1988 I designed an ARM2 based computer (my Merlin 4, which was only
built in 1992 when the ARM2 was already obsolete) and wondered if it
could emulate a PC fast enough to be usable. I had written an ARM
assembler and a friend did an ARM emulator running in QNX on the PC, so
we wrote an 8088 emulator in ARM assembly. We then ran some simple 8088
programs on the PC emulator running on the ARM emulator running on the
PC. This allowed us to figure out that an 8 MHz ARM2 would be able to
run PC programs at nearly the speed of a 4.77 MHz 8088. Though there
were much faster PCs at the time, the original configuration was still
being sold and was popular enough that this would have been considered
usable. It was not enough to convince my partner, however, which is why
the machine was not finished in 1988.

-- Jecel