Analog CMOS switch. A switch is closed if the appropriate control line is HIGH, otherwise it's open.
![[Picture of 4066]](pics/4066.gif)
Fig.: 4066
Pin | Signal | Dir | Note
-----+--------+-----+-----------------------------------------
1 | I1 | in | Input #1
2 | O1 | out | Output #1
3 | I2 | in | Input #2
4 | O2 | out | Output #2
5 | C2 | in | Control #2
6 | O3 | in | Control #3
7 | GND | - | Ground (0V).
8 | I3 | in | Input #3
9 | O3 | out | Output #3
10 | I4 | in | Input #4
11 | O4 | out | Output #4
12 | C4 | in | Control #4
13 | C1 | in | Control #1
14 | Vcc | - | Supply voltage (5V).
Of course, all inputs can be used as outputs and vice versa.
In the C-64, there are two 4066, one of them is responsible for selecting 2 of 4 paddles, the other one for coupling the address lines of the color RAM with the bus.