I have one 877A and I would like to monitor 16 inputs (or more if possible) which I cannot do it by continues monitoring the inputs to go low/high as PIC has to do some other stuff in the main routine.
Although I can use some PortB pins as they have interrupt on change BUT I do not want to use programming pins as inputs as I want to leave them for ICSP which leaves me with very few pins with 'change on interrupt'.

So, is there any other IC/technique which I can implement in this case which can help me to monitor many inputs using 1 interrupt or something like that.