Hacking the PSX Password entry

Well, I have primarily played PSX Doom my whole DOOM life, mostly because of the palette effects and the better sfx/bgmusic. Naturally I am also plenty 'fluent' in PC Doom action, and one day I was bored and started messing around with the Password entry screen in PSX Doom.

For some reason I thought of combining a very well known PC-Doom cheat with this password system: IDKFA. Except, IDKFA is only 5 characters long, and a PSX password is 10 characters long, plus there are no vowels to use in a PSX password. But I tried anyway, so I translated that into 11DDKKFFBB for the PS. Lo and behold, that password has worked, and sent me to Lvl 45: Tenements with 150% Health, 75% Armor, and 100 bullets with a handgun and chaingun. Next, I took an existing Password that I earned from actually playing the game: 8R491FDJJJ, which is for Redemption Denied. I tried rearranging some letters and got some weird results. 984R1FDJJJ sends me to Lvl49: The Catacombs with everything but a Shotgun and Armor. I've tried a bunch of other combinations, replacing the triple J's with other characters, flipping the F and the D, etc. Most, or all, worked.

I've even uncovered passwords that took me to some of the secret levels including Club Doom (88DDKKFFBB), all I needed to do was replace the first two 1's with some character that wasn't 9 or !. It's kind of cool, but I still haven't figured out any patterns or anything. If anyone out there has come across an explanation for this PSX-Doom Password system, I'd like to check it out. If not, I will continue my research and post any breakthroughs.

Awesome dude! Keep er'up.

This isn't too surprising. The Final Doom passwords are all based on particular values (such as armor, health, ammo and number of weapons) tallied at the end of the level. One small change can have a dramatic effect, and each time you play the password will be slightly different.

RedComa, if you want some PSX Doom password lists to hack or play around with:

Normal starting status, all maps, all skills - (txt/zip)
Normal, plus super shotgun, Ultimate Doom - (txt/zip)
Normal, plus super shotgun, both Episodes - (txt/zip)
Maximum starting status, all maps, all skills - (txt/zip)
Low/hard starting status, all maps, Skill 4 - (txt/zip)

I really think it shouldn't be to complex, there has to be certain combinations which represent the different values of health, armor, ammo and what weapons the player has. However, it is still a Password, in the sense that these parameters shouldn't be blatantly obvious so anyone can just type in whatever they want. I think it might be a system where the first "set" of characters will change a lookup table for the second set, and so on until the last set. This is why you can't type in random stuff, because it tells you that it is an invalid password, similar to magic numbers or header signatures at the beginning of a file, to designate which version it is, etc. It's sort of like a harder version of Jumble, where you AREN'T given the decoder key, haha.

Here goes some ones I discovered whilst messing with the password menu once:

pssw0rd---
d00mmnl---

The last 3 characters can be any available alphanumeric character, as long as they are the same (ie 777, for pssw0rd777), or you can change the last alphanumeric character one direction or the other in the line (ie pssw0rd778 or pssw0rd776). However, any one further than that won't work (ie pssw0rd775) nor will any random combination (ie pssw0rdab7).

Also, not all combinations will necessarily work (pssw0rdxxx doesn't work, if I recall correctly).

You just have to play around with it.

I like the ones that start you with amounts of health/armor/ammo that you can't get normally (like starting you on MAP02 with 375% health, for example). Unfortunately, once you grab a pickup related to that stat, it drops back to normal (ie, picking up a health potion with 375% health will knock you down to 200%health).

Would be nice if someone actually knew how the password system worked, algorithm wise.

Kaiser said:

Would be nice if someone actually knew how the password system worked, algorithm wise.

If only they released the Playstation source! That would be fun.

RedComa said:

If only they released the Playstation source! That would be fun.

I wait for the day for something like this to happen (and as far as I am aware of, Midway has it for keeps).

I don't think Midway is known for releasing secrets, especially useful ones...

would be awesome if they did...
This sounds interesting, unfortunately I never picked that one up...

very cool project, keep us updated :)