Originally posted by FabianFnas
Thank you very much, DeepThought, for you're taking up time to explain for me.
Some more follow up questions...
So if I take out the processor altogether, then nothing will happen, no beeps, no BIOS execution, no nothing, dead as a rock? (I would guess the rock.)
When we hear the beep or a series of beeps if something is wrong, is it the CPU that ...[text shortened]... it really is, and his authority has decreased a bit in my eyes. But I like his teachings anyway.
Assuming it's a standard set up the various fans will turn, but without the CPU it's a pile of electronics generating heat. With the CPU it's still a pile of electronics generating heat, but you'll get some usefulness as a side effect of the heat generation.
Whether you get beeps or not with a missing CPU depends on the motherboard hardware. I doubt it, but I've never done that experiment.
Intel didn't make the Z80 (except possibly under licence), Zilog was formed by a former Intel employee, but it's not an Intel product. On ARM the first instruction is loaded from memory location 0x0 and I think that's a common choice, but Intel do it differently. The first instruction loaded is away from physical memory location zero on all Intel processors, certainly since the 286 and probably all of them since the 8086. I couldn't remember the address so I googled the question and got three different answers...
According to the Wikipedia page  I looked at it's location FFFF:0000 for all Intel processors, according to the Dr Dobbs page it's FFFF:FFF0 16 bytes away from the top of memory. The Dr Dobbs page is quite detailed and explains the issues about the processor set up well. However the third page I got from google  which is rutgers.edu gives F000:FFF0, so take your pick.
The processor has that location built in, when it starts up it clears its registers and then sets its instruction pointer to a built in value and starts loading from there. Since the early machines had 16 bit address buses I'd imagine that for them the starting location was FFF0.
Edit: I've forgotten how segment offset adressing works, I think Wikipedia and Rutgers are saying the same thing. I'm abit suspicious of the Dr Dobbs location but it's looking like a typo. The Dr Dobbs article gets the 32 bit addressing mode address the same as the other two articles 0x000FFFF0.
Edit 2: The memory location I was failing to remember is 07c0 but that is where the operating system is loaded to later on. I never knew the BIOS load point, but do now. Both the Dr. Dobbs and Rudgers articles are worth reading.