Seeing as Computercraft is not officially developed anymore, it seems wise to integrate the most up-to-date computer mod.
Here's a simple driver example, which allows access to the vanilla noteblock.
It would be really amazing to have a fully automated missile system.

Even though we do not officially support it, there is a 3rd party icbm-oc-addon now for 1.12 which should work for you:
https://www.curseforge.com/minecraft/mc-mods/opencomputers-icbm-classic-addon/files/2913483

It would indeed be nice to have, feel free to submit a pull request for it, if you got working code.

Support will need to be added as an addon rather than built into the mod directly. As I do not want to delete code each time we move MC versions and OC doesn't update fast enough to keep the support.