Need help with fork adjustments 1990 .

[Tuneforkfreak]

Can some one please give me a simple explanation of what the adjustments in my 1990 model forks do and what takes place when I turn them? I only have a service manual and I can't find info on adjustments. I've looked through some threads but keep finding ten page write ups on general fork string  theory and relativity 101. TMI for me. My fork has three red slots on the outer top tube each slot is a different thickness, The dampener screw has a red dot on it as well, I can hear it click if i turn it but nothing seems to change

[FJ_Hooligan]

If you push down while turning the adjuster clockwise, you will increase spring preload.  The damping will also increase. 

If you what to change only the damping, then turn the adjuster without pushing down.

[Tuneforkfreak]

Ya man that's what I'm talking about left fork was free to move about but the right fork didn't want to budge at all. The dampening screw pushed down but that was about it. Sprayed some Kroil then used a large brass pin and gave some coaxing taps then it freed up. Thanks so much, ( push down) who would of thunk it