Skip to content Recently we featured an unusual Commodore 8-bit computer on the bench of [Tynemouth Software] — a Commodore 64 in a PET case. One of the unique parts it had was a board which took the composite output from the mainboard and split out the sync pulses for the monitor, and now they’re back to give it a full reverse engineer . Perhaps the first surprise is why this board is necessary at all, after all one might expect an 8-bit machine to have those signals already at hand. It seems that the VIC chip inside the 64 did the combination to composite internally, so no such luck for the Commodore engineers. The board they designed then is a complete and very well-engineered sync splitter. The technology of a video signal has its origins in the 1930s, so it’s not hard to extract both vertical and horizontal sync pulses with little more than a few passive components and a couple of transistors.…