In my playing around I am now trying to assert an input and have a corresponding output change.

My first test was to simply have the output follow the input. Note that I did not set the input to "1" to initialize it.

My first try things seemed to work. Using Vcc as my input I could touch the input pin and the output led toggled properly. After about 5 or 6 transitions though the output dropped and stayed there no matter the signal on the input.

I recompiled with the input bit being set to initialize it and this made no difference. I tried a second IC and no difference either. I have a third unused processor but am afraid to try as it is my last one. Is it possible to damage the input using Vcc? The specs say it can take up to Vcc+0.5. Vcc is a steady 5.4V.