Here is how to read data from a KDE KT-2280/KT-2220 or other similar magnetic swipe card reader.

The reader has a RS232 interface (it draws operating power from the computer/cash register). It wants to talk at 9600 baud, 8 bit, no parity, no start bit, no stop bit, no flow control.

Make sure cu (terminal/dialler program) is installed, and at the command prompt, type

 cu -s9600 --parity=none -l /dev/ttyS0

(presuming the card reader is attatched to the first serial port [COM1])

The DTR (Data Terminal Ready) pin on the serial port should go high and the card reader should beep. Swipe a card through, and the red or green LED should light up. The data on the card will be shown on the command prompt.

To terminate cu, type ~. (in other words <alt gr> + ~, then space, then . )