[TUHS] The birth of the Z3

[Clem cole]

Yes of course.  I used to program the 8 so I remember.  But I (sloppily) think of them the same way although you are correct they are different in implementation.  But my key point is until conditional instructions that change the path come along we are not to the general purpose computing platform.  

Their is a open question about the need to support self modifying code too.  I personally don’t think of that as important as the need for conditional instructions which I do think need to be there before you can really call it a computer.   But that’s my opinion and others clearly believe neither are needed.  

Clem

Sent from my PDP-7 Running UNIX V0 expect things to be almost but not quite. 

> On May 13, 2018, at 2:52 AM, Greg 'groggy' Lehey <grog at lemis.com> wrote:
> 
>> On Saturday, 12 May 2018 at 11:04:26 -0400, Clem Cole wrote:
>>> On Fri, May 11, 2018 at 6:21 PM, Dave Horsfall <dave at horsfall.org> wrote:
>>> 
>>> Way back on this day in 1941, Conrad Zuse unveiled the Z3; it was the
>>> first programmable automatic computer as we know it (Colossus 1 was not
>>> general-purpose).  The last news I heard about the Z3 was that she was
>>> destroyed in an air-raid...
>>> 
>>> This pretty much started computing, as we know it.
>> 
>> But .. until we also include a conditional branch the ability to do
>> self modify code we don't really have the machine with think of as
>> the automatic programmable computer.
>> 
>> Check out:
>> http://page.mi.fu-berlin.de/rojas/1993/Who_invented_the_computer.pdf its a
>> fun read.
> 
> That's an interesting document, but it refers to the Z1, not the Z3.
> But Wikipedia confirms that the Z3 also didn't have conditional
> instructions.
> 
> Conditional branch is only one way to do that, of course.  The PDP-8,
> for example, didn't have one, just (like many machines of the day)
> conditional skip instructions.
> 
> Greg
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