IBM 6094-020 Lighted Program Function Keys

I think I found the programming specs: http://codeninja.de/lpfk/ According to that page, it speaks 9600 N81 and the input and output sequences are trivial. I have two samples .. both are behaving the same way, which is to me 'non-functional'. I thought I had a cabling goof so I started with the multi-meter and started tracing things. To make a long story short, I think the cabling is fine, and the units are just goofy. (Although they are both goofy in the same way, so I suspect something else is wrong.) I can't get any output from the units - not even noise. Sridhar - what position is the switch on the backside supposed to be? I think it is supposed to be set to the 'lightening bolt', and that the other symbol means loopback. Is yours connected via a serial style cable, or the round DIN connector to a graphics input feature adapter? If it is serial, would you mind connecting it to a PC comm port, setting the port to 9600 N81 (no flow control), and seeing if you can get some output when a key is pressed? Glen - the HP button box you describe is amazingly similar, but the case is a bit different. Those buttons don't look like they have lights ... the IBM version does, and the lights are controllable from the host machine. Mike