Computer Basics - How Does It Work?

[iowahawk43]

I've searched high and low for an answer to this question and have not found what I'm looking for. Can someone here help me?

Here is my question: how does a computer work?

I know, it sounds basic so let me tell you what I am after. We know that electricity first enters the power supply. Then we know that the computer boots up - goes through BIOS and so on. I can grasp all of this, but what happens between the power supply and the boot?

In my mind's eye I see one wire leaving the power supply with an electrical current going somewhere to the motherboard. And once the FIRST instruction begins, I can understand how the CPU can function past that point. But what starts that first step and how?

My guess is that the charged wire completes some circuit that is the hardwired first step in a computer "coming to life". Further, my guess is that this hardwire circuit is the "first instruction". Could someone give me some terminology or names to look for in my goal to actually learn how a computer works?

Thanks in advance.

[Jiggy]

I would start here with Introduction to the PC (http://www.pcguide.com/topic.html).

[classicsoftware]

Have a look at this (http://www.newportharbor.us/computerworks.htm)

[saphalline]

my guess is that this hardwire circuit is the "first instruction".Eh, not really. I mean, this used to be true back in the early days of computers, but modern PC's are much more complex than this.

First of all, PC's no longer consist of just one microprocessor. The main CPU is still the big bad number-cruncher of the bunch, but the chipset alone often contains various microprocessors with minor purposes around the system. And of course the largest and most complex processors today are actually on vid cards.

If you want to learn the basics of how a computer starts up, I'd suggest doing some searches on the BIOS and POST routine. The main mobo BIOS is actually the first program to get executed in a PC (it acts as a mini-OS) and is initialized after the POST routine. The POST routine itself is a programmable self-check test that is run by the chipset after the power has been turned on. But for the power to turn on, the mobo's power sub-layer must receive adequate power from the PSU on all the rails, which activates the "Power_Good" signal, etc. It's a long and complicated chain of events.

Look it up if you really want to, but I think you'll get a better grasp if you search for old info on the original IBM PC or PC XT.

[jlreich]

Have a look at this (http://www.newportharbor.us/computerworks.htm)
Hehe, so that's what's going on inside there. :p :cool: