Sets the I/O port specified by the num argument to the state specified by the state argument.
io.portset(num as pl_io_port_num, state as byte)
Line/Port Manipulation Without Pre-selection, io.portget
Platform-specific. See the list of pl_io_port_num constants in the platform specifications.
0-255. Each bit of this value corresponds to one member I/O line of the 8-bit port.
No line pre-selection with the io.portnum property is required and the value of the io.portnum will not be changed.