First of all, hi everyone, first post here.
I'm trying to run a Z80 CPU together with Arduino and here is my current layout:
The program loaded into Arduino simply sends 1 Hz CLK via pin 13. The whole thing is powered from a 9V battery.
As soon as I press down and hold the little switch, the thing starts working, NOPs (opCode is zero - all data lanes are GNDed) are being executed and PC increases (you can tell thanks to the AO led).
The problem is, when I remove the marked resistor from the layout (and thus the green LED stays disconnected), the CPU is not working, which is weird, because there is no logical dependence between this part of the layout and the CPU.
Another thing is, with or without this resistor, the CPU get pretty warm/hot within 2 mins - should these old babies even get warm?
Unfortunately, my electrical knowledge is pretty low and maybe there are some electrical problems with my layout, so maybe one of you could tell me what's the problem and how to solve it. Thanks in advance.
PS. If this is wrong category, please move this topic.