Eric,

 

The folks who made ENIAC programable didn’t use the word “program” but they ran 
what we would now call programs. The fact that the word wasn’t used doesn’t 
mean the concept hadn’t already been invented. I did check and Turing didn’t 
use the term in his paper “On Computable Numbers” and whilst the work “emulate” 
is now associated with Universal Turing Machines I am inclined to agree that 
Turing probably didn’t see this as “Emulation” in the modern sense of the word, 
but to me, there seems to be little difference between a UTM and SIMH….

 

Returning to ENIAC if you read Mark Priestley & Thomas Haig’s paper

 

http://eniacinaction.com/docs/AddressableAccumulators.pdf

 

you can see they describe ENIAC in stored program mode as “a microcoded 
interpreter for a virtual von Neumann architecture machine” which seems to me 
to be equivalent to what IBM did, some years earlier. 

When I spoke to Mark Priestley after the talk..

 

http://www.computerconservationsociety.org/lectures/2015-16/20160511.htm

 

he was quite clear that they configured ENIAC to emulate an EDVAC style machine 
and used the word “emulate” several times in the talk, so I would argue that 
the ENIAC pioneers invented the concept but did not name it as such…

 

Dave

 

 

 

 

From: Eric Smith [mailto:space...@gmail.com] 
Sent: 30 October 2017 11:18
To: General Discussion: On-Topic and Off-Topic Posts <cctalk@classiccmp.org>; 
Dave Wade <dave.g4...@gmail.com>
Subject: RE: Which Dec Emulation is the MOST useful and Versatile?

 

On Oct 29, 2017 09:54, "Dave Wade via cctalk" <cctalk@classiccmp.org 
<mailto:cctalk@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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