IBM 6094 Lighted Programmable Function Keypad - Some Documentation...

I tried debugging mine again. I'm still where I was six months ago. The RS232 breakout box is showing me: Negative 10 volts on pin 2 of the DB9 serial connector. Pins 1 (CD), 6 (DSR) , 8 (CTS), 9 (RI) - positive 5 volts Everything is measured with respect to pin 5, which is ground. So, my interpretation .. it just never sends any bits on pin 2. There is a 'loopback' switch on the back of the unit which changes the behavior of the unit, but does not cause any bits to be sent. In the 'normal' position the unit appears to be inert. In the 'loopback' position the lights respond to key presses, but it doesn't send data. (Nor should it.) I have 2 or three that behave like this. Does anybody have one that they know works on something other than an RS/6000? Mind is connected using the serial cable option and a wall wart for power. Mike