I'm a computer programmer and use Xcode so I am constantly scrolling up and down. Often times I would like to move the page down but not as much as the "Page Down" keyboard key moves it. I would like to move it half the distance as it usual moves. I feel like I have experimented with every combination of "Page Down" with shift, option, control, command, and fn. Also, I used all those controls with the down arrow keys with no success.
Maybe I missed something? Is this even possible? I use a program called Dragon Dictation that accepts AppleScript so if somebody knows how to code this so I can use it in Dragon Dictation it would be very helpful.
SOLUTION:
Dragon Dictation is no longer supported. I'm using Apple's built-in dictation.
I created the AppleScript code in Script Editor:
tell application "System Events"
key code 125
key code 125
key code 125
key code 125
end tell
Then from Accessibility > Dictation > Dictation Commands, I create a word and in the "Perform" drop down box select Run Workload, and select the AppleScript file using the code above that was created in Script Editor.
Best Answer
As answered in the question linked to by klanomath's comment, ControllerMate can be used to set up keybindings that simulate scrolling an arbitrary amount.
However, this approach has limitations:
(Oops! I placed a bounty on this question worth 100 reputation points, not realizing that the points would be "escrowed" and that since I'm not a frequent user of apple.stackexchange.com, I would then not have enough reputation points to comment. Otherwise I might have just commented after klanomath. I'm not attempting to win my own bounty by answering... Hoping someone else can come up with an approach that overcomes the limitations mentioned above.)