My understanding of how interrupts (and more specifically, interrupt daisy-chaining) works in the Z80 is limited, to say the least, so if I get anything wrong please correct me.
Anyway, let's say I have two PIO chips to control two different peripherals (let's say, a character LCD display, and some switches, but I'm sure that's not very relevant). I've connected the IEO pin of one PIO to the CPU's INT pin, and it's IEI pin to the other PIO's IEO. I then connected that PIO's IEI pin to a 5 V rail. I got this information from this image: (but instead of the three different peripheral chips they use, I just have two PIO chips.)
Anyway, my understanding is that this kind of configuration means that if the second PIO (the one directly connected to the 5 V rail) pulls its IEO pin low, the other PIO will not be able to send an interrupt. Correct?
My issue is this: How would I cause a PIO chip's IEO pin to go low? And how can I actually send an interrupt from one of these peripherals? My initial thought would be that I'd just pull the CPU's INT pin low, but that doesn't make sense the more I think about it.
(On a side note, any idea what the INTACK pin is on that diagram?)