[GreenKeys] Rock and Roll Teletype 'experts'

[Tony Duell]

> 
> Tony Duell wrote:
> > Said books also contain a description of a lovely electromechanical FIFO 
> > system used to store train descriptors on the London Underground (and its 
> > associated binary to 1-of-n decoder) ...
> 
> You can see the 1-of-n decoder in the London Transport museum
> in Covent Gardern.  At least, you could last time I went there,
> once again it was some years ago.  Anyone been there recently?

As is the FIFO (again, it was there when I went, which was some years 
ago). They looked to be complete, and wired up, but alas they were not 
operational when I visited the museum.

Since, unlike the Science Museum, the London Transport Museum charges an 
entrance fee, I've not been recently.

> 
> The actual decoder, BTW, is all done in massive brass, copper and
> Bakelite.  It's a form of relay logic, I suppose.

Not Bakelite (it's earlier than that). I thought the base looked to be 
marble, or comething like that. And yes, it's the standard relay-logic 
decoder tree. I have the schematics, etc, in that book I mentioned.

-tony