Originally Posted by Dutch
Find the ImpulseCommands function...i think it's in weapons.qc. Look at how they tie in the various impulses. Now look at the QuadCheat command. You can replicate this command for the other power-ups. Look at CheckPowerUps command to see all the player fields regarding powerup behavior, so you'll know what to include in your new impulse commands.
Impulse12 is already done if you download progs 1.06 source. Or you could simply re-write impulse 10 in reverse order.
Use a good text editor like Notepad++ to edit the files. Use FTEQCC to compile the source into a new progs.dat.