# I/O
- [Intel-P8254](../datasheets/Intel-P8254.pdf) (Programmable Interval Timer)
- [NEC-uPB8214C](../datasheets/NEC-uPB8214C.pdf) (Priority Interrupt Controller)
- [6522](../datasheets/w65c02s.pdf) (VIA)
- [6551](../datasheets/w65c51n.pdf) (ACIA)