Quoted from barakandl:I have one of these things.
As do I. I use it on all ICs for my complete boards before I insert them into a socket.
Quoted from barakandl:I have found a few odd balls it cannot do but for the most part reads them all back.
I have found this as well. One IC that I see a lot is 74LS245 and it can't seem to recognize this one.
Everything that barakandl said has been my experience. I find this tester invaluable.