I am currently working on a door counter. I have based it on the 16f84A (I bought a tube of them years ago before I worked out they weren't really that great). In keeping with the ancient PIC, I found ancient schmitt trigger to debounce. The TP4304. Its stamped '78. I scored a bunch of old CMOS from a closing electronics store.

http://www.datasheetarchive.com/dl/Datasheets-112/DSAP0044783.pdf