I have two 8255 peripherals that interfaced to the 68000. I have 2 ADCs, 2 DACs and 2 LCDs to interface to the 8255. Is it possible to multiplex? The ADC is ZN448E and the DAC is AD558. The LCD is standard 16 pin. Besides I have 2 analog multiplexers, 4051 that will require 3 control lines.
To interface the peripherals to the 8255 ports you will have to use one port(e.g. 8 bit) to generate the chip select for the different peripherals and the control signals needed. Each peripheral requires a specific read/write cycle you need to generate in software and meet their timing diagram. Could be a lot of effort and slow. If you can get access to the address and control signals a hardware decoding would be more useful.