In your guys experience where have you seen the Test mode/self test switch mostly going to on the CPU?
When I'm looking at the schematics the test mode switch does to a harness and going to multiple chips and it doesn't say there is connects to the CPU pin, they don't make it clear as to where the test mode/self test switch is going to on the CPU
You MUST understand that it is
CPU specific and very dependent on what the engineer wanted to do. If we take your previous choice of the 6502 or Z80, you
must understand what the NMI does before you understand the circuit that goes into it. I do not have the time or the desire to explain the nuances of the NMI to you. You are free to research it yourself as many others have done. Once again, Google it.
MAME likely has those diagnostics already archived.
Can I load a different diagnostics test from another arcade game to test a different arcade game?
This must be answered on your own. Take the test diagnostic block from one arcade and compare it to another. Are they the same?
To understand why, you MUST understand the CPU you are working on and you MUST understand the schematic. Non one will do this homework for you. GOOGLE IT!
Are the Diagnostics test only ment for the one arcade game or can It be universal to test all arcades with?
Google it.
Most arcade games in the 80's had 4 to 6 ROM chips , which one has the Diagnostics self test code on it?
Seriously? This question is so asinine that it deserves no answer whatsoever other than, Google it.
When using an EPROM programmer zif socket, I put the ERPOM chips into to READ the code, but how do I know which one is the Diagnostic self test code?
I'm just trying to extract the Diagnostic self test code for each arcade game in the 80's
I want to Load different Diagnostic self test on a EPROM chip to on different arcade logic boards
Then no one here will help you as there is no logical reason for a beginner-1, such as yourself, to even be messing around with that. Anyone else who has enough inkling as to how to do that, will know enough not to do it as it would be a total waste of their time. Sorry...