6 I/O pins are exposed, the first three bits are used for bank switching, the second three are for datasette control. https://www.c64-wiki.com/index.php/Bank_S

6 I/O pins are exposed, the first three bits are used for bank switching, the second three are for datasette control. https://www.c64-wiki.com/index.php/Bank_Switching#Expansion_Port https://www.c64-wiki.com/index.php/Bank_Switching#Expansion_... https://www.c64-wiki.com/index.php/Cassette_Port https://www.c64-wiki.com/index.php/Cassette_Port