How to determine the port numbers for peripheral devices?

[smwikipedia]

Hi, guys. This is my first thread here. And this place is awesome! So happy no to find this place too late.

I know that peripheral devices such as a hard driver, a floppy driver, etc are controlled by reading/writing certain control registers on their device controllers.

I am wondering about the following questions:

•Is it true that when these peripheral devices are plugged onto the computer, the addresses(port numbers) of their control registers are thus determined by how they are attached to the address bus (i.e. the hard-wiring rules, not any soft things)?
•Who makes the scheme of the port number assignment?
•If I was given a naked computer(with no operating system and with many peripheral devices), how could I figure out the port number assignment so I can use them to control peripheral deveices.

Thanks for your patience and reply. 8^)

[Combuster]

There are three classes of devices: some devices use predefined ports and addresses, some are wired or jumpered, and some are plug-and-play. Most of the hardware present since the 386 is of the first kind, they are also the first things you'll use.
Every device that comes from the old age and was optional usually is of the second type (soundblasters etc), most newer stuff is plug-and-play, which means the BIOS assigns addresses to them so they don't overlap.

Basically, you'll need to know what kind of device you are dealing with to find out to what ports they respond.