don't click here

Puggsy's SRAM-based copy-protection thang

Discussion in 'General Sega Discussion' started by MarzSyndrome, Jun 23, 2012.

  1. MarzSyndrome

    MarzSyndrome

    Everything is going to the beat. Member
    By "patch it out" of course, I mean "hardpatch it out".

    The fact is: it's hit-or-miss whether you can complete Puggsy on a particular emulator - it depends on if the emu author was aware there was copy protection in the game in the first place. So I feel it'd be better if we could just kill the protection call in the rom itself, amirite?

    I know MD games use MC68000 language - the same language used in Amiga and Atari ST - but I'm unaware of any handy debugger in MD emulators that would allow me to track instructions live, piece-by-piece, like I can with WinUAE.

    Sooooooooo....... anyone able to help nip this one in the bud? :)
     
  2. MooMoo

    MooMoo

    Leader Bean Member
    This may be completely missing the point of what you're after, but if you just want to finish the game, the Mega CD version doesn't have the copy protection.
     
  3. Rika Chou

    Rika Chou

    Tech Member
    5,276
    169
    43
    If you just want to play it, just disable SRAM in whatever emulator you're using. (I know kega has this option, not sure about others)
     
  4. MarzSyndrome

    MarzSyndrome

    Everything is going to the beat. Member
    Alas, not all emulators provide any SRAM-related options. Certainly not a good chunk of the ones for handhelds, for one thing.

    Take the Dingoo A320 for example. Precisely none of the three known MD emulators for it (the default one, DingooSMD and PicoDrive) can get past the post-1st-boss protection check to allow further access. To make it more problematic, the Dingoo/Dingux port of PicoDrive is based on an older version, without the later fix notaz applied to the GP2X/Wiz/Caanoo/Pandora versions to bypass the check.

    So yes, I think it's important that we force-disable it from inside the rom to make it universally-compatible with every emulator for every platform out there. Some emus will likely never receive another update, after all.
     
  5. Black Squirrel

    Black Squirrel

    no reverse gear Wiki Sysop
    8,589
    2,483
    93
    Northumberland, UK
    steamboat wiki
    Hacking ROMs to use with emulators is much the same as messing with websites to get them to work with old browsers. Really the push should be to get the emulator to improve, as awkward as that might be.

    I'd have thought the solution would be to produce test ROMs and have developers work to get their emulators to "pass". But I don't know if anything exists which tests SRAM stuff.
     
  6. Vangar

    Vangar

    Member
    3,654
    62
    28
    I agree with this. Having an option to disable SRAM should be pretty standard by now!
     
  7. Espyo

    Espyo

    Member
    81
    1
    8
    Portugal, Porto, some street
    A Pikmin fan engine - Pikifen (https://pikminfanon.com/Pikifen)
    TCRF explains it a bit well. http://tcrf.net/Puggsy
    In short, it's kinda tricky to remove it. The best way would really be to just disable SRAM saving on your emulator. Heck, the only emulator I can think off that doesn't have this is Genecyst!
     
  8. LocalH

    LocalH

    roxoring your soxors Tech Member
    I wouldn't know how to find it, but I wonder if there was a copier crack for Puggsy back in the day. Games weren't always 100% cracked but they got damn close.

    As long as the ROM is not redistributed (where people who aren't aware it's not a virgin dump might spread it around as such), but only a patch to hack it, then I see no problem with it as a stopgap measure.

    TCRF doesn't have the addresses, but if there are four SRAM write checks then it should be feasible to NOP those instructions out and not give a damn about the actual SRAM write. I don't have a Puggsy ROM handy to look at right now, though.
     
  9. MarzSyndrome

    MarzSyndrome

    Everything is going to the beat. Member
    EdgeE*u or E*uParad*se are your best friend.
     
  10. dsrb

    dsrb

    Member
    3,149
    0
    16
    >implying people on Retro don't know how to find ROMs, especially a Tech Member
    >lol
     
  11. Vangar

    Vangar

    Member
    3,654
    62
    28
    This isn't 4chan, wtf >_>
     
  12. LocalH

    LocalH

    roxoring your soxors Tech Member
    By "not handy" I meant it's on my back up DVD and not on my hard drive and I'd have to retrieve that disc. I know how to find ROMs, lol.
     
  13. MarzSyndrome

    MarzSyndrome

    Everything is going to the beat. Member
    Ah, I see. Still, I'd imagine heading to a ROMs place to grab a quick copy of the ROM would be quicker than searching for the disc - at least that's how it is for me. XD
     
  14. You might want to try your hand at any [f] "fixed" roms from GoodGen if they exist. IIRC those exist to hack games into working on emulators or 90s cart copiers.
     
  15. LocalH

    LocalH

    roxoring your soxors Tech Member
    There isn't one, at least that I can find. Just U, E, and two "betas", one of which is labeled [a1].
     
  16. Vangar

    Vangar

    Member
    3,654
    62
    28
    Just had a quick look as well, definitely nothing in GoodGen 3.0.

    And while we are on the topic of Puggsy, have a look at this cute little Demo, an early Amiga program with Puggsy:

    http://www.youtube.com/watch?v=8kIqu_S0txc
     
  17. Aesculapius Piranha

    Aesculapius Piranha

    つづく Oldbie
    4,534
    143
    43
    Unknown
    Diva
    Puggs in Space was the Sequel that was never made teased at the end of the game. Not sure if the Amiga demo came before or after Puggsy 1. (Guessing before.)

    Also, I w0d lik a Sonik 2 Baeta r0mz.
     
  18. ICEknight

    ICEknight

    Researcher Researcher
    That demo came way before the videogame. I remember a nearby store that used to have it on display, back when Rainbow Islands was released for the the ZX Spectrum...
     
  19. Vangar

    Vangar

    Member
    3,654
    62
    28
    I believe the Puggs in Space reference in the ending credits is actually referring to this old test demo. Doesn't it say 'watch out for puggsy 2' or something like that in the end credits instead?
     
  20. Travelsonic

    Travelsonic

    Member
    827
    20
    18
    Actually it does. I commented on a YouTube video of that stage asking just that, and Tim Wright himself responded [to the video uploader's surprise as much of my own].

    He removed his comment, but the response to the comment is still there [http://www.youtube.com/all_comments?v=SoEC2Ih9Ijo]



    I'm left wondering, what is stopping somebody from making a disassembly of Puggsy, finding the write checks [4 of them if the article is 100% right], and just disabling them?

    I mean, if that's all that it protection consists of, the write checks itself, it sounds easier than others are making it out to be? Wouldn't WHAT they do, where the look, read, write (?), etc, become irrelevant if we can just disable them outright?

    EDIT: IF the wikipedia article here is correct, and the check occurs "Before starting any level after the fifth [level]" [basically, from the first part of "The Red Woods" onward], then it could make things easier.