Specifically, from the source.bungie.org User Support FAQ, question 15.:
"15. It's true Aleph One has built-in CHEAT CODES?
The cheat codes are disabled by default. Here's what to do to activate the codes:
1. Open Aleph One with ResEdit.
2. Open the TEXT resource and create a new resource within it.
3. Type: .
4. Save and quit.
While playing the game, hold down the control key and type:
NRG Replenish your energy. Type it twice and you'll get 2x energy. Type it once more and you'll get 3x energy.
OTWO Replenish your oxygen.
MAP Show the enemy as red squares, ammunition as white squares, and projectiles as yellow squares in the overhead map.
BYE Gives you invisibility. Type it twice to become twice as invisible.
NUKE Gives you invencibility - sorta. You'll still take damage from those dam Vacuum Bobs or any network player with the Fusion gun.
SEE Give you infravision. The world will become blue, with no lighting effects. Friends will show up painted in yellow, enemies in red. This is also know as "stereo vision" (as popular as that "smell-o-rama" idea).
WOW Gives you extravision.
MAG Gives you the Magnum pistol plus 10 clips each time you type it.
RIF Gives you the Assault Rifle plus 10 grenades and 10 clips each time you type it.
MELT Gives you the Fusion gun plus 10 batteries each time you type it.
QWE Makes you jump. If you type it while running, you'll jump higher.
SHIT Everyone's Mortal But Me.
YOURMOM Save your game anywhere."
