PA0-PB7: Bidirectional ports A and B (stick direction, paddle triggers,
etc.)
CB1-CB2: Port B control
Vcc: +5V power
R/W: Read/write direction
CS0: Chip Select
CS2: Chip Select (active low)
CS1: Chip Select
Ø2: Sync
D0-D7: Data bus
RST: Chip reset
A0-A1: Address bus
IRQA-IRQB: Port A and B interrupt lines
CA1-CA2: Port A control
Note: I have no confirmation of the above descriptions. This is just
my best educated guess, using my knowledge of microcomputer design, the
function of the PIA processor, and the interaction between the custom IC's.