ebay - cardamatic

[Geoff Reed]

At 09:16 AM 2/14/2005, you wrote:
>On Sun, 13 Feb 2005, Geoff Reed wrote:
>
>>isn't it just conductive traces on plastic?
>
>You computer people, you so advanced!
>
>
>Nope. Plastic card (credit card thickness, or less) with
>pencil-sized holes in it. The "reader" is a matrix of electrical
>contacts. You shove the card in it, it insulates the non-punched
>contacts. Simple!
>
>Alas, hard to reproduce the cards automatically. Easy with a hand
>punch though.

ah, i saw a tube tester once that used plastic cards with conductive 
(graphite?) black/grey traces on them, that's why i asked