Author: Ratko V Tomic
Date: 07:12:32 10/30/99
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> There is another speed-killer. If you use software of "Creative" (sound > blaster) then turn off the "joy-stick" driver by all means. On one of our > PC's it was responsible for a slow-down of 30%. My guess is that the > driver polls for input too many times a second. The joystick drivers usually use calibrated software loop to time precisely the discharge time for a capacitor through the resistors (which are controlled by the joystick position, one for X one for Y direction). To catch exactly the discharge half-life of the capacitor, which in turn determines the resistor value, they read the corresponding register repeatedly (since there is no interrupt to indicate the half way charge) and then convert these loop counts to X and Y coordinates (or moves) through scaling and table lookups. It is one of those hardware standards (like much of other IBM PC standards, including DOS, BIOS, Video, x86 family CPU instruction set, etc) that got stuck in the first half-baked design that came along and seemed to work, sort of.
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