This is the thread that just won't die. Even fearless leader hiccups occasionally:
Any keyboard that has function keys that are recognized, can easily be programmed to eject or do anything you want is OS 9, we have covered that here 
You cannot program an F-key to raise or lower volume in OS9……
period. F-keys require that the OS has built-in code that will recognize that you just tapped a key and that means "execute xxx function" i.e. "eject CD" or "open xxx app" etc. HOWEVER:
There is NO "step volume up" OR "step volume down" function in the operating system.Audio level in OS9 is controlled by the graphic slider in the Control Panel. That slider is mapped on a pixel-by-pixel basis so that it's "position" corresponds to a specific percentage of 100% volume.
What you want would require that there be a function that would "increase system volume by x increments" which would require that there first BE a defined set of volume increments (other than "one percent of 100") that will cause the System Volume control in the Control Panel to change a specified amount such as "up 5%" or similar.
No such code exists in ≤OS9. (That's why Cliff tore his hair out trying to write an extension to do it)
This little conundrum is just (a minor) one of the thousand-or-so reasons Apple dumped the entire MacOS for OSX.
The interface only addresses the frontmost app. If - in this example - volume level is not baked into the app code, there's only one way to "reach around" it to access the little bit of reserved System function that exists in the Control Panels:
The Control Strip. That cleverly avoids disrupting the frontmost app and allows certain changes in low-level hardware control directly. Unfortunately, Apple did NOT provide a preset volume up/down incremental function there - only the graphic slider…SO you
can mouse over to the volume Control Strip Module, click and drag the slider up or down to change volume but you
cannot order it to move or the system volume to change a pre-specified amount by tapping a keyboard key.
You just can't.Now… just to beat this nag to death even longer, you
can use QuicKeys to make volume changes at the touch of a key. It's difficult and requires some work but it's possible. You can record a set of QK macros that will "grab" the mouse cursor and click it twice in the volume Control Strip module: First to open it, second to click on a specific point along it's travel. You record a number of macros (the more there are, the finer the increments) and assign them to a series of the F-keys in the top row… the leftmost being say 0%(mute) and increasing maybe 10% at a time to the rightmost one at 100%. You can use fewer if you tolerate larger increments.
This may or may not be suitable depending on the running app (or especially a game) because you're causing QK to momentarily
grab control and execute a couple of very rapid clicks then
return control to the running app. It's a very short interruption (in human time…an eternity in CPU time), but an interruption nonetheless.
Sometimes the best way to program a solution is to NOT program it at all. You want to make something happen… you
think "well, it should just be a key" but maybe it doesn't
have to be……
as long as the solution gets you where you want to go.I present: The simplest way to change your system volume at
any time. It does NOT interfere with any running app and works reliably 100% of the time… OBSERVE
The powered computer speaker with integrated volume control. Comes complete with a friggin'
subwoofer for $20 or so on fleabay.
PROBLEM SOLVED
