On Tue, 11 May 2010 19:06:12 +0100, Orchid XP v8 wrote:

> Darren New wrote:
> 
>> Also the narrator of Cosmos.  I don't know anyone who didn't watch
>> Cosmos.
> 
> Apparently you don't know me then.
> 
> What's Cosmos then?

A TV programme that was narrated by Carl Sagan.

http://tinyurl.com/26x3ade

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>> What's Cosmos then?
> 
> A TV programme

Ah, well, that would explain it then. I don't watch TV. :-)

(The irony is that I don't watch TV because there's never enough science 
to watch...)

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

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On 11/05/2010 2:29 PM, Mike Raiford wrote:
>
> Actually, in the vein of computer science: For the fun of it I'm
> designing CPU from scratch. I plan to build it with TTL gates


Feck! About 35 years ago I built a digital clock out of TTL. It used 30 
amps at 5 volts Vcc. The power supply was bigger than a modern PC.


> Eventually, I want to take a simplified version of that design and
> create a CPU entirely out of relays.

You are mad, you know ;-)

>
> One consideration for the relay version is that the machine should be
> able to halt and only resume processing on an interrupt. So, ideally,
> you'd give it inputs, issue a command, and send it clacking away to get
> a result.

Does your wife know about this ?


> The TTL version should be fun, too. I plan to have lots of LEDs to show
> what's happening inside the machine.

I hope that you have comprehensive fire insurance :-P



BTW let us know how you get on. :-)


-- 

Best Regards,
	Stephen

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On 11-5-2010 15:29, Mike Raiford wrote:
> On 5/11/2010 7:41 AM, Invisible wrote:
> 
>>
>> You know that there are people who do scientific experiments *about*
>> computer programs, right? ;-)
>>
> 
> Yeah :)
> 
> Actually, in the vein of computer science: For the fun of it I'm 
> designing CPU from scratch. I plan to build it with TTL gates after I 
> have the design complete and have vetted it through simulation. I have 
> the ALU designed. (Fairly simple, it can add, perform bitwise logic and 
> shift, as well as calculate the twos complement. Other operations will 
> take multiple cycles) I also have most of the control logic put 
> together, but I need to make some changes to ensure an ALU instruction 
> can occur within 2 cycles (One to latch the ALU result, one to store the 
> result in the accumulator)

Still more complicated than my own 1984 design. ;)

> Eventually, I want to take a simplified version of that design and 
> create a CPU entirely out of relays. Obviously, I'd need keep the design 
> as simple as possible, but still functional to keep the relay count 
> down. Something about a bit stack of clacking relays with blinking 
> lights really appeals to me. That machine will likely still have IC 
> memory, though, but the registers will be relay latches.
> 
> One consideration for the relay version is that the machine should be 
> able to halt and only resume processing on an interrupt. So, ideally, 
> you'd give it inputs, issue a command, and send it clacking away to get 
> a result.
> 
> It's fun stuff, and occupies a good deal of time. Also a great way to 
> learn HOW a computer like the one you're sitting at actually works. e.g. 
> how each instruction of machine code does what it does, etc...
> 
> The TTL version should be fun, too. I plan to have lots of LEDs to show 
> what's happening inside the machine.

If you do it to give you new insights into how to make a CPU than that 
might qualify you as a scientist. The border is vague, possibly 
something along the line of how deep the insight is, how many people 
already know it (if nobody than you are definitely in) and if you are 
able to pass on that knowledge. If you are paid to do so that also 
helps, but you aren't.

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Stephen wrote:

> Feck! About 35 years ago I built a digital clock out of TTL. It used 30 
> amps at 5 volts Vcc. The power supply was bigger than a modern PC.

5 amps?!

How thick was the damned wire??

> You are mad, you know ;-)
> 
> Does your wife know about this ?
> 
> I hope that you have comprehensive fire insurance :-P

Hmm, yes... I think they're calling you a nutjob, Mike.

> BTW let us know how you get on. :-)

THIS IS THE REAL WTF! o_O

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

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On 11-5-2010 20:06, Orchid XP v8 wrote:
> Darren New wrote:
> 
>> Also the narrator of Cosmos.  I don't know anyone who didn't watch 
>> Cosmos.
> 
> Apparently you don't know me then.

you are too young.

> What's Cosmos then?
> 

http://en.wikipedia.org/wiki/Cosmos:_A_Personal_Voyage

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On Tue, 11 May 2010 20:31:10 +0100, Orchid XP v8 wrote:

>>> What's Cosmos then?
>> 
>> A TV programme
> 
> Ah, well, that would explain it then. I don't watch TV. :-)
> 
> (The irony is that I don't watch TV because there's never enough science
> to watch...)

You would probably find QI interesting, not always about sciencey stuff, 
but a good programme to watch.

But that also would explain why you haven't heard of some fairly well 
known scientists or be aware of what their achievements are, things like 
that tend to be newsworthy, and people often hear the names while 
watching the news or various news commentary.

Jim

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andrel wrote:

> Still more complicated than my own 1984 design. ;)

Anybody else attempted this crazy task?

> If you do it to give you new insights into how to make a CPU than that 
> might qualify you as a scientist. The border is vague, possibly 
> something along the line of how deep the insight is, how many people 
> already know it (if nobody than you are definitely in) and if you are 
> able to pass on that knowledge. If you are paid to do so that also 
> helps, but you aren't.

Depends on your definitions. I would say that anybody who follows the 
scientific method is a scientist, regardless of whether what they 
discover is actually new. But then, if you mean a *professional* 
scientist, or even a *reputable* one, that's another matter... ;-)

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

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On 11-5-2010 20:05, Orchid XP v8 wrote:

>> Again, Jane Goodall probably fits that bill.  If we counted people who 
>> have lived in our lifetimes, Carl Sagan.  Vint Cerf, Sir Tim 
>> Berners-Lee, both of whom I previously mentioned, are also quite well 
>> known.
> 
> I would refute that... Perhaps I need to do a straw poll when I go down 
> the pub tonight? (Although I can't *pronounce* most of those names, so...)

Ah, this would be the perfect time to mention Dijkstra.

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On 11/05/2010 8:31 PM, Stephen wrote:
> On 11/05/2010 2:29 PM, Mike Raiford wrote:
>>
>> Actually, in the vein of computer science: For the fun of it I'm
>> designing CPU from scratch. I plan to build it with TTL gates
>
>
> Feck! About 35 years ago I built a digital clock out of TTL. It used 30
> amps at 5 volts Vcc. The power supply was bigger than a modern PC.

I just remembered that I download from the net the circuit diagrams of a 
Honeywell H316 which was made using TTL (and ferrite core memory) :-D

-- 

Best Regards,
	Stephen

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