SOFTWARE for PIC16F84A:     Program code is written using MikroC. Code is so small and simple. When it detects state 0 on port A4 it begins a loop and counts from 0 to 3800 (end of samples), and resets to address 0 till next press of the switch.
Links to some usefull web sites.
Willem Eprom Programmer
AllPIC Programmer
MikroC
To build this project you'll need Eprom & PIC programmer...
Donations are appreciated.