Which Dec Emulation is the MOST useful and Versatile?

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.