ENIAC programming Was: release dates of early microcomputer operating systems, incl. Intel ISIS

dwight dkelvey at hotmail.com
Thu Sep 17 16:44:38 CDT 2015



> From: spacewar at gmail.com
> 
> On Wed, Sep 16, 2015 at 4:18 PM, Dave G4UGM <dave.g4ugm at gmail.com> wrote:
> > It is notable that in order to solve all problems, a computer must permit
> > self modifying code.
> 
> From a theory of computation view, I don't believe that's true.  Any
> computable function can be computed by a fixed program.
> 
> For a particular computable function, there may be a more efficient
> implementation using self-modifying code.
> 
> On the other hand, computing a particular computable function may
> require an arbitrariy amount of recursion, so it may take an
> arbitrarily amount of writable memory.  The recusion may, of course,
> be implemented as some equivalent that doesn't require the computer to
> have explicit subroutine calls or stack, but the memory may still be
> required.

That may be true for computing but I'm not sure if it is practical
for real time control of complex systems.
Dwight

 		 	   		  


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