Hey guys,
I know that in normal desktop computers, the CPU interfaces the video card, sound card, USB card, etc by the PCI slots but what about laptops? I've heard that laptops also have a PCI bus even though do don't have a PCI slot so does this mean that the same address space that would normally be allocated for the PCI bus in a desktop computer, is allocated for these devices(embedded GPU, etc) in a laptop?
Laptops use the PCI bus too, you just don't have any easily accessible expansion slots. The PCI standard defines the electrical and logical parameters that devices must comply with in order to interact. But there's no requirement for the physical component to hold slots for adding new hardware.
oh, so it just like a desktop except they don't have the slots?
Simplified: yes. It's the same as with hard disks and screens. The technology is the same, but has to be fitted into a smaller space, so some non-essential amenities are cut.
Yes, everything's hardwired right in, nearly. The PCI interface is kept so the operating system can tell what drivers to use for everything through plug-and-play.
Laptops usually do have one mini-PCI/PCI-e slot though, because getting a product approved for wireless is a pain. They'd much rather buy an approved wireless card off-the-shelf than put their entire laptop through some slow, expensive FCC test procedure every time they switch wireless chipset manufacturers.