== PAL I/O port ==
Note that no settings are stored in the Gate Arrayregarding register 3, but the PAL and Gate Array share an I/O port address.
Bit 14 of the PAL selection address must be at 1 on CPCs equipped with CRTCs 0, 1, 2. It can be at 0 or 1 on CRTCs 3 and 4.