On Thu, 2006-02-16 at 23:14 +0000, Howard Winter wrote:
> Peter,
> 
> On Wed, 15 Feb 2006 22:39:07 +0000, Peter Onion wrote:
> 
> > On Wed, 2006-02-15 at 15:06 +0100, Lembit Soobik wrote:
> > 
> > > We developed the new generation machines using core memory and blocking 
> > > oscillators (rather than flip-flops, monoflops) because they worked with 
> > > only one transistor. Transistors were expensive, around 5 to 10 $ a piece.
> > > 
> > > Lembit
> > 
> > That's interesting.  The only computers that I know of using cores for
> > logic werebuiltby Elliott Bros.in England.   There is a brief
> > description of the logic here
> > http://members.ozemail.com.au/~jacksmth/ell803b.htm
> 
> Hang on - we were talking about core *memory*, not core logic elements! 

We WERE but the conversation has moved on !


>  I think pretty-much all 3rd 
> generation computers used core memory, so IBM, ICL, English Electric, Burroughs, Univac, and so on, all used 
> it.  I was rather impressed when I went back to the college where I'd done my A Levels, and had been an 
> operator on an IBM 370 (semiconductor memory), to see the old ICL 1904 that they'd inherited - you just turn 
> on the power and start using it - no need to IPL because the operating system is still in (core) memory!
> 
> I seem to remember hearing that the Elliot 803 had a "Squawk box", a sound producing device whose output 
> varied with some parameter - perhaps the program counter?

Yes, but it wasn't a separate "box" but a standard feature built into
the console.  It was connected to the "a statisicer" in the instruction
register, so any instruction in groups 4 to 7 would produce a "click" of
length determined by the time the instruction took to execute.


>   The sound it made could tip off those with an 
> experienced ear that there was a problem, such as an infinite loop.  Anyone who has heard the sound would 
> recognise it as a computer from that era, as it was often used in films featuring computers to make it more 
> exciting!  :-)

I'll try and make a recording on my emulator running the algol compiler
and put it on my web site for you to listen to :-)  I can't do it now as
I'm in the middle of converting all the modules to use a different
service discovery library.


> Oh, and as it happens Borehamwood, where Elliott's was, is about 5 miles from here!

Peter

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