A mechanical counter driver

This electro-mechanical counter was bought cheaply as an unwanted spare. Such a counter is sometimes useful, but cannot be used with modern electronics without a driver because of its 24V rating and minimum pulse length. Also it is very fast and counts multiple times with many switches.
This is the third iteration of drivers for this counter.. The first, in 2010, used discrete ICs. The second, in 2012, used a Picaxe 08M. This is an improvement of that for the following:
1. Use connectors for power and trgger instead of pigtails.
2. Use an efficient switching power supply with a line cord instesd of a plug-in transformer.
3. Beef up the 5V regulator and make its output available for an external trgger source.
4. Provide a programming connector.
5. Use a brighter LED.
6. Use an interrupt-driven program which accepts any input longer than 2 milliseconds.
This is the overall view of the counter. The box is sized to hold credit cards.
This is the top of the counter. The cover is removed.
This is the program of the counter
This is the schematic of the counter