Under the microscope: Space Griffon VF-9 (PlayStation)
Cheat codes that have been hiding for 30 years, now found
Space Griffon VF-9 is a 1995 PlayStation game from Panther Software. It can use a memory card to save game progress, but it supplies passcodes “for those players that do not have a Memory Card.”
You can resume a game with a passcode from the main menu. Valid passcodes allow you to skip forward or back in the game (see this guide for examples).
Whenever I see a text entry field in a game, I put a distinctive string into it and then search for it in memory.
Once I know where input is stored, I set a read breakpoint for that location. This reveals how the game processes the input.
For this game, the passcode is stored (as plain ASCII) starting at 801fbf94. The function at 8002ef68 trips the read breakpoint, and it does something interesting: it compares the passcode buffer with these strings:
80060b14 "KAMIKAZE"
80060b20 "ATLUS"
80060b28 "PANTHER"
80060b30 "GRIFFON"
80060b38 "NINJYA"
80060b40 "LUNAR\0TEARS"If there’s a match for one of them, it updates some values in memory.
What are these for? Cheating! The memory addresses associated with the special passcodes match the ones on GameShark and Action Replay sites. They hold various stats, like shield level and energy.
I couldn’t figure out how to take advantage of these cheat effects, however. The game shows an error message after you put in the special passcodes and doesn’t let you continue. Once you start a new game (or load a previous one), the stat adjustments are wiped out.
Jason at PlayStationLibrary.com figured out that you can get to the passcode screen another way, after you’ve started playing:
Take out your memory card.
Press Select and then choose System > Load from the menu.
You’ll be prompted to enter a passcode. Entering one of the special passcodes still leads to an error message, but the stat adjustments will persist.
The first special passcode, KAMIKAZE, is kind of an anti-cheat! It reduces all of your stats to a single point.
These three passcodes increase your stats:
ATLUS: +10 armor (stored at
801e0079)PANTHER: +10 power units (stored at
801e0078)GRIFFON: +10 repair units (stored at
801e0077)
The NINJYA passcode gives you all of the information in the Select menu’s DATA item: VF (mechs), Floor Maps, Machines (enemies), and Monsters (more enemies). This information is stored starting at 801e0080 in memory.
Side note: this “Machine” data entry somehow survived the localization process…
The last passcode, LUNAR TEARS, sets your shield (801e002a), body (801e005a), and energy (801e0058) stats to their maximum values.
Outro
Many thanks to Jason at PlayStationLibrary.com for figuring out how to get to the passcode screen from within the game.
As far as I can tell, these effects aren’t in the Dreamcast remake of Space Griffon VF-9 – alas. There definitely isn’t a passcode screen, and there doesn’t seem to be code for restoring the stats to full.
More retro game reverse engineering explorations are coming! Subscribe to get the next article as soon as it’s published:
