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

[Paul Koning]

> 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?

An example where that could be useful is in validating an emulation.  I did that recently: running an EL-X8 emulation implemented in ALGOL (by Dick Gruene) on an EL-X8 emulation in SIMH.  Run the test program that comes with it both on the nested emulation, and "standalone" on the outer emulation.  Compare the outputs from the two runs, and fix or justify any differences.  It helped significantly, especially because the inner emulation came with a bunch of important details about strange machine quirks.

	paul