If the ADC and LCD share a common 8 bit port. Then you want to access the ADC you pull the CS pin low and keep the E input low. Then you want to access the LCD you keep the CS pin high and then give a strobe signal on the LCD E pin. A strobe signal equal to taking the E pin high and then low again. I see you have a pin PC7 on 8255 free to use for the CS signal. It would be more easy if you quit being in panic mode, and then focus on your task. Solving one problem at the time. As a start draw a new schematic if you feel the common port solution is something you want to followHow can I do that ?
Thanks !