I have the TL866CS and I can confirm that it does work for testing logic IC's, but keep in mind that only the most common chips are supporting, and it doesn't autodetect the chip based on truth tables; you have to tell it which chip you are testing, and it will tell you if it passes or fails. The primary function of this device is programming memory chips and AVR micros (I love that it supports HV programming for resetting fuses).