hi, I am a little bit confused about how the 8255 Ports are mapped: PA - 0x4000, PB - 0x4001, PC - 0x4002, PCNTRL - 0x4003. 4002H is 0100 0000 0000 0010B. Is this considered as a conrol word? how come it is 16-bit? Any hint would be really appreciated. The only think I can understand is the selection of the Ports with last 2 bits.