Your coin acceptor should have a microswitch.
The microswitch in the coin acceptor works the
same way as a microswitch on an arcade button
or joy stick.
If you want to connect your coin acceptor to your
pc, you will need an encoder. there are many
different kinds. Wire encoder to microswitch,
connect encoder to usb port.
http://wiki.arcadecontrols.com/wiki/Encoders