Good news!  Thanks to the Oddity of Hyrule, we have finally discovered the Zelda 2000 debug screen!  To unlock this little feature, you obviously need to crash the game (just play around with the Gameshark, it's not that hard).  Then, enter in the following buttons in this order:
A + B + All the C buttons + Z + D-Left + Start
Once you've done that, the screen should appear, scrolling automatically through the various debug info.  I have NOT confirmed this sequence yet, as my N64 is at the moment expansion pak-less, but it does sound authentic and quite obviously, if anyone says that it doesn't work, then I'll take this down.  If it works like it's supposed to, though, we may be able to unlock some more from Majora's Mask!  After all, Majora's Mask held some of the beta stuff from Ocarina of Time's production.  Who says it doesn't have more?