ACT Apricot keyboards, or infra-red japes

[Tony Duell]

> 
> Hi folks,
> 
> Recently I've picked up the bits of the infra-red Apricot keyboard that 
> Jules investigated at my place and left in bits all over one of my 
> sofas :)
> 
> It's a membrane activated by springs and quite a lot of the keys don't 
> register with the host machine which in wired keyboards points to a 
> dodgy membrane.....however, in this case there might also be some issue 
> with the infra-red emitters, so short of dragging a digital video 

Surely there's one encoder and IR transmitter for the entire keyboard 
(there may be several IR LEDs, but normally they're wired in series and 
send the same information). In which case if _any_ keys work, then it's 
very unlikely the problem is with the IR transmitter.

> camera down to my southern home is there a way of watching the 
> infra-red emitters to see if they're working OK?

There's a little circuit in an old issue of the Maplin Magazine for an IR 
remote control tester. I've found it very useful for testing IR 
keyboards, detecing the beam in a laser printer, etc. Such circuits have 
also appeared in Television magazine over the years.

There used to be (and probably still are) cards available -- about credit 
card sized -- coated with some special phosphor material. You 'charge' 
them by exposing them to normal light, and then they glow if hit with an 
IR beam. You can recharge them many times, I am not sure what the 
lifetime is.

-tony