Talking to hardware

Just like any other software does it, they instruct the CPU to send data and instructions (technically more data) to the I/O subsystem.

What really happens though is more of a layered approach. The OS dictates what gets sent to the hardware when; your program makes requests to the libraries, which then make requests to the drivers, which then pass it on to the OS.

So, when you make a DirectX/OpenGL call, you''re calling your code, which invokes code in some resident library, that propogates down the abstraction sandwich, nd eventually turns into electrical signals going across the I/O bus to your video card or sound card or what have you.

Hmm..ok is there something I can read about all this on the net? Sorry for double post btw.

Drive it like you stole it.

You dont really need to have a deep understanding of electrical engineering unless you are trying to understand the electrical properties of the processor itself. In order to understand the instructions set you just need to have an understanding of digital design. Basically the processor has been built to recognize certain patterns of bits to represent instructions which tell it where to send data or to do something to the data (add, subtract, multiply etc.) When you get down to the nitty gritty of it, the computer is nothing more than a really fast calculator. Isnt it amazing what you can make a calculator do?

"I may not agree with what you say but I will defend to the death your right to say it."
--Voltaire

[edited by - cmptrgear on May 7, 2003 5:03:03 PM]