British Science Museum needs a lesson in history

From: Derek Peschel <dpeschel_at_u.washington.edu>
Date: Fri May 28 18:54:22 1999

Tony Duell wrote:

> > "The Museum is the only place where you can have this opportunity to
> > work with the first computer."
> >
> > Konrad Zuse might have a problem with this.
>
> _At_ the musuem they advertise the machine as the first electronic
> computer with random-access memory. I have far less of a problem with
> that statement :-)

Except that Zuse's Z3 also had random-access memory, just not for the
program. IIRC the Z3 had/has 64 data registers.

In fact (as Sellam might remember since this was presented at a speech at
last year's VCF) there is a way to give the Z3 random read-only access to
its program. The Z3 reads its opcodes from a strip of 35mm movie film; the
film can of course be looped together; most importantly the Z3 will _stop_
if it encounters an arithmetic exception. So the "only" work left is to
partition the program into sections and explode each arithmetic operation
into a conditional operation based on the current value of the section
counter. It's possible to do the exploding without causing any more
exceptions. I think the section counter needs to go in one of the registers.

Hans Franke might know more about this.

-- Derek
Received on Fri May 28 1999 - 18:54:22 BST