Er, no, 8 4Mx1 chips isn't going to work for bank A in a IIsi. You have installed an 8-bit wide memory; 24 data lines are not connected to anything, even assuming the rest of the pinout is the same (which I doubt).

I've been posting too late at night and some of the other things I wrote about required address bits and memory sizes are not correct, because I was not keeping sets of facts straight. I'd start writing one thing and finish writing another. I should probably unwind it and write a correction.