· C64 + Mega DriveBugs and pieces of code: behind the scenes
I've collected the most instructive porting bugs on a dedicated page, each with its code fragment and its moral. Three from the C64: the SID crackle (the pop was in the attacks, not the notes), the 6502's register that erased the clues, and the memory silently overflowing into the charset. Three from the Mega Drive: the purple screen of a Z80 held in reset, the stripe that wouldn't crumble on tile graphics, and the dual target, the trick that lets you test the console without the console. Every snippet is told in plain words.