How to generate SMPTE timecode?

As the title suggests, has anyone successfully generated SMPTE timecode from a pic?

I have the need to adapt an ancient timer unit (LSI & discreet logic) into a SMPTE timecode stream so other modern displays can 'slave' off the main timer unit.
The original 'ancient' timer can't be replaced as it provides other features in it's installation, so i need to add some adaption ont it, not replace it!

I imagine i would simply take the 1 second (or 10th's or 100th's if available) and feed that into a pic to be converted into a timecode stream...

I realise another thread on here dealt with READING timecode into a pic, but i'm going the other way ;-)

Any help or links would be greatly appreciated.
Marty.