Rivendell supports a variety of I/O cards. IIRC, you may be able to use serial and possibly joystick ports. If you're up to a bit of hacking, you can run Rivendell on a Raspberry PI and use its GPIO pins. Check out the mailing list at http://caspian.paravelsystems.com/mailman/listinfo/rivendell-dev You can subscribe to the list and ask your questions there and get lots of help. You can also look through the archives of past posts.
As has been often recommended here, the Rivendell software can do just what you need. The RDCatch application (part of Rivendell) can record based on time or contact closure. Totally free software, only cost is hardware. As it runs on Linux, it does not require cutting edge hardware. Recently retired office computers generally do just fine. If you have adequately made the transition from tubes to solid state or survived updating from carts/vinyl/cassettes to computerized audio delivery, you are certainly capable of transitioning to Linux.