You can check at http://commodore64.se/wiki/index.php/Commodore_64_Memory_Map http://commodore64.se/wiki/index.php/Commodore_64_Memory_Map what kind of stuff go

You can check at http://commodore64.se/wiki/index.php/Commodore_64_Memory_Map http://commodore64.se/wiki/index.php/Commodore_64_Memory_Map what kind of stuff goes in the zero page for Commodore's kernal and Basic. In particular, Basic puts the whole "get next byte" routine there at $0073. It is self-modifying code where the address of the next program byte is the operand of an LDA instruction. Placing the whole routine in zero page saves enough cycles on incrementing the next program byte that it's worth spending 5% of the whole zero page on it.