Which Dec Emulation is the MOST useful and Versatile?

Eric Smith spacewar at gmail.com
Mon Oct 30 06:18:27 CDT 2017

On Oct 29, 2017 09:54, "Dave Wade via cctalk" <cctalk at classiccmp.org> wrote:

I am not sure they invented computer emulation. I think that the concept
Emulation/Simulation is as old as, or perhaps even older than computing.
Whilst it was a pure concept Alan Turing's "Universal Turing Machine" was a
Turing machine that could emulate or simulate the behaviour of any arbitrary
Turing machine...

1. Did Turing use the word "emulate"? I honestly have no idea. My (possibly
wrong) impression was that no published literature used the word emulate
with that meaning (one computer emulating another) before the IBM papers.

2. What a UTM does is simulate another machine using only a general-purpose
machine. In fact, the UTM is arguably the most general-purpose machine ever
described. What IBM defined as emulation was use of extremely specialized
hardware and/or microcode (specifically, not the machine's general-purpose
microcode used for natively programming the host machine). If anyone else
did _that_ in a product before IBM, I'm very interested.

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