How does a computer program actually work?

lundyjb

I really want to know the physical path an electrical signal takes on its journey. For example, when i press the J key on my keyboard, an electrical impulse is sent where? to the hard drive where the keyboard program is stored? Could someone just give me all the stops that electrical signal will take in order to be eventually displayed as a J by the pixels on my screen? Thanks a bunch

the_emi_guy

There is no single electrical signal that conveys the J key on the keyboard to the J shown on the display. In fact there are thousands of electrical signals involved. The dirty details of the sequence of all of these signals needed to perform this seemly simple act is what computer/electrical engineers learn getting their degree.

Many of these signals are inside of integrated circuits (processor memory etc.).
Many are on the motherboard (address/data lines), USB lines, interrupts.
Many are within the keyboard itself (inside microcontroller and on keyboard motherboard).

And it depends on stuff like:
What kind of keyboard (traditional, USB, wireless).
What kind of computer (Apple, PC, Sun workstation, Ipad)
Which operating system (Linux, Microsoft).

dlgoff

Well, this shows "one path" in a microprocessor: http://education.mrsec.wisc.edu/Edet...cpu/cpu2b.html

berkeman

Here is some reading that you should check out at HowStuffWorks.com:

http://www.howstuffworks.com/pc.htm

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