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Thread ID: 23188 2002-08-09 10:44:00 A diversion... Analogue Computers Terry Porritt (14) Press F1
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69776 2002-08-10 10:02:00 >>>Thats more interesting info, JM, I would like to have one also, those in the pictures are really collectors items going back a bit.

I've done quite a bit of research into them and have played around with one for about a month. They are really quite easy to use once you get used to them. Only problem is when the paper is starting to peel off and isn't lined up properly.

The first one I saw was when my Year 12 (6th Form) maths teacher showed the class one. He'd found it when he was working on a farm in Scottland somewhere. He had no idea what it was.

Last I looked they went for around $60-110 here in NZ.
-=JM=- (16)
69777 2002-08-10 10:08:00 Also a different model was also found in one of the old math supplies cupboards at my school. Looked as if they had them as the school calculators (upgraded the abacus).

Also have a look here (cgi.ebay.com)
-=JM=- (16)
69778 2002-08-10 22:01:00 How about this...
www.slideruleguy.com
pporritt (819)
69779 2002-08-11 00:56:00 I see my 'lad' joined in.

I have been getting Fowler confused with Fuller slide rules.
The mortar-like cylindrical one is the Fuller and its scale length is 41 feet.

www.hpmuseum.org

Fowler were noted for their circular slide rules and the one I have is a Magnum just as illustrated here (www.gemmary.com), in picture B
Terry Porritt (14)
69780 2002-08-11 02:52:00 Thanks, Dad...

All this talk about early computers, and the person who really deserves more recognition is overlooked - Charles Babbage. You can read all about him at www.cbi.umn.edu
Apparently, the University of Auckland has a collection of some of his material and manuscripts
pporritt (819)
69781 2002-08-11 03:14:00 Well, Babbage originated the standard government computer contract syndrome: delivered "late, over budget, and not working." (But it was capable of working --- he just never made it go before "improving" it.) The Science Museum (Kensington?) built enough of it according to his designs to prove that it was possible. Though the difference engine was not "really" a general purpose computer. Graham L (2)
69782 2002-08-11 08:02:00 Do you know how valves were invented?
OK I will tell you,

The first electric lamps deposited soot on the glass, my guess is that this bugged some people as after a while the lamp would fog up with soot and then you would turn on a black lamp, so some clever person thought if they put a electrode inside the lamp and made it positive in respect to the heater the shoot might get attracted to the electrode and not the glass, well I think that failed, so then they made the electrode negative, Then they noticed when the electrode was positive current flowed, when the electrode was negative no current would flow, it took someone a few years after that to think of a application which turned out to be the valve. Not sure how they invented invisible soot but it works really well after a while the build up is so great it snaps the heater.
E.ric (351)
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