Computer in 1900,

Gavin Melville gavin.melville at
Fri Feb 15 19:33:56 CST 2008


I had looked at relays, and while there certainly were relays in 1900, I
doubt they were very good in terms of bounce, actuation time etc.   The
building where I work has an Otis made lift dating from 1980, done
completely with relays.  It's fairly unreliable, and a lot of the relays
have to be fiddled with springs, copper disks, iron slugs etc.  (Some of
them were designed that way, and some just needed it to make them work).

I've seen the stuff on the relay computer, and I suspect that simply
would not have worked in 1900, but works due to modern relays. 

> -----Original Message-----
> From: cctalk-bounces at 
> [mailto:cctalk-bounces at] On Behalf Of Tony Duell
> Sent: Saturday, 16 February 2008 12:06 p.m.
> To: cctalk at
> Subject: Re: Computer in 1900,
> > Relays: Possible, but even in 1945 was very hard.  
> Available by 1901 at
> > the latest.   
> I would say relays were definitely available in 1900. I have 
> a book from
> 1895 [1] on electric bells, and while I can't remember if 
> relays are explicitly mentioned (I think they are), the 
> trembler bell was certainly well-known at that time. 
> A trivial modification to a trembler bell turns it into a 
> relay with one normally-closed contact (just remove the 
> hammer and gong, and electrically disconnect the contact from 
> the coil and bring them out seprately). It's then only a very 
> small step to add a normally-open contact, and indeed other cotnacts.
> [1] My second-oldest book on electrical stuff. I have an 1892 
> book on telephone installations.
> -tony

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