“In which chip/chips are located post, bios, setup and boot”


Hello everyone,

I’ve always wondered where this four programs are located, because there are not available on hard drive, but there are first programs which pc notices while starting up. My guess is ROM, but not sure. I suppose there are more chips on which are this programs located?

In: 4

You are correct that there’s a ROM chip (technically, an EPROM, as it’s reprogramable) that contains the BIOS (Basic Input Output System). The BIOS contains the mini programs for the Power On Self Test, Setup and Boot.

As for the Boot program, all it does is read the data from the Master Boot Record of the hard drive, which is a standard, loads the boot sequence from there, executes it and from thereon, the sequence handles the rest of the operating system.

OK, you used a lot of technical terms in there, lets break them down:

POST – This stands for Power On elf Test. So, it is not exactly a program, but more of a process. Basically, your computer checks to see if you have all the things needed to operate (like any amount of RAM memory) and that they seem to be in working order.

Setup – So, there are two setup systems on your computer, one is a BIOS Setup and it is on the BIOS. This one is just used to setup basic componenets, like how many hard drives you have, that sort of thing. BIOS Setup won’t even make the hard drive usable or even bootable, you need the other Setup System to do that. The other is the OS setup which is either on the internet or on physical media. that is what makes your Hard drive usable and provides you with an interface for apps and the internet.

Boot – So, this what we call the entire process of powering up all the devices and loading the Operating system (like Windows) to a point where the end users can do things. Before the Hard Drive gets involved, most of it is on the BIOS. once the Hard drive is involved, there are two components. One is a boot manager that is not on your C: Drive. And the rest is part of the OS which are hidden files on your C: Drive (do not do anything to these files directly). So, it is sort of like that “all squares are rectangles but not all rectangles are squares.” POST happens during every Boot, but the Boot process continues after POST is done.

BIOS – This stands for Basic Input/Output System and it is sort of the bare minimum the computer needs to load the hard drive. It is loaded on a chip on your motherboard. In modern systems that chip can be updated/modified with utilities provided by the maker of your motherboard. But otherwise there are not components of BIOS on your C: drive. To put it as simple as possible, the BIOS makes sure that the power supply is not throwing an error, that there is some sort of graphics card that can at least display text, that there is some kind of RAM that the mother board can see and that the CPU is not reporting an issue. After that, it can do basic stuff like enable/disable secondary systems (like network or sound). But it won’t generally throw an error say if your sound card is not operational as you can use a computer without a sound card.

I know that is a lot, so let me know if I went too far over your head.

There’s an EPROM microchip on the motherboard/main board that is specific for that board. It has a specific BIOS for that chip and board (different boards might have different circuitry, CPU architecture, etc). This is why if you go shopping for motherboard, one of the specs is the type of BIOS.

The first thing BIOS does is execute POST to make sure the main components are working, then it looks at the first partition on each hard drive for a boot loader, which loads the OS.