Hi...

No One Mentioned That The Purpose Of The Pullup & PullDown
Ment To Be Specially For DEFAULT Logic Or Tri-STATE
Situations... Means That When U Build A Keyboard, The
Default Voltage Level In The Ports Can Be At High Level
(Pull Up) Or At Low Level (Pull Down), And When U Press
The Botton, It Changes The Voltage, And Then U Know That
A Botton Is Being Pressed, And Act As Necessary...


Now U Can Gather All The INFO Here (Replies) And
Understand What Is PullUp & PuulDown.