>AFAIK, windoze continually interrupts its execution to check whether the mouse has moved, whether a key has been hit (which would count as I/O or 'graphics') or whether another has to be dispatched etc.
Off the three above only the last is true. The mouse device and the keyboard device generate hardware interupts which interupt the processor. So Windows (and other OSs as well) don't need to poll, but are notified by the hardware. Each time a key is pressed, or released, an interupt is generated. After the key is pressed, and that interupt has been generated, the keyboard repeatedly generates interupts as fast as the keyboard repeat rate tells is. The mouse generates upon mous button press and release. The mouse movement interupts are generated whenever the mouse has been moved a certain distance that depends on the mouse resolution. The latter, mouse movement, it the most resource consuming of all the above. I remember well Solitair I used to play on Windows 95. The cards were jumping over the screen drawing nice pictures one you succeeded. The cards moved quite fast to present an nice animation. You could slow down, and even bring it to almost starve, when you moved the mouse fast and faster. That was a good visualization on how much resources supporting a mouse may consume. -- Peter Hunkeler ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
