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How is it even possible?

Discussion in 'Dreamcast' started by Cloud121, Oct 29, 2001.

  1. Cloud121

    Cloud121 Member

    I don't want to be banned or anything, but I've had this question on my mind for a few days. how is it even possible to copy GD-ROM games? I mean, they use about 1 gig of data (well, probably only the launch titles could be copied), and the largest CD-R is 700 mb at the moment. Plus don't they use some kinda multi-code thing for the data like PSX games? And no I don't even have a DC.
  2. Fabrizo

    Fabrizo New Member

    Well, you know how its possible for DVDs to be double layered, such as in the PS2 DVDs (4.9 GB) VS the XBox ones (8.7 GB), its just like that, only done with normal CDs I think.
  3. ExCyber

    ExCyber Staff Member

    I haven't seen any 100% authoritative info on this, but the only theory I've heard that sounds reasonable at all is this: GD-ROM is actually CD-ROM with at least one "special" session that has the pits half as long (but normally wide, otherwise the laser would probably be unable to read it), and the 12X "GD-ROM reader" is actually a 24X CD-ROM reader running at half its normal rotation rate (but with the decoding electronics running full-speed). I don't know or care how warez groups do disc ripping, but I know that it can be done by connecting the DC to a PC (e.g. via a serial cable) and running a program on DC to read the files from the disc. I don't know and (for now) don't care about the details of these methods.

    Anyway, from what I've seen, not too many games actually use more than the capacity of a CD. For those that do, various stuff can be chopped up to make it smaller; DC warez groups apparently do this routinely. Some examples:

    - Remove the right channel of stereo music, making it mono

    - Re-encode FMV and/or audio at a lower sampling rate or bitrate

    - Completely remove "useless" FMV

    - Remove audio tracks, hacking the game or maybe the TOC so that the game still plays music where it normally would

    In other words, one of the bits of BS typically spread about "evil software pirates" (i.e. that you'll end up with inferior quality compared to an original) turns out to be true for DC warez. A number of people are also concerned about increased wear on the DC's laser motor due to games that have their file ordering screwed, thus requiring the drive to seek more often - I don't really know whether or not this fear is justified, but I wouldn't rule it out...
  4. IceDigger

    IceDigger Founder Staff Member

    the largest CDRs available are 900 MB, not 700. there are 90 min and 99 min blanks, but not all burners can write them. mine can go up to 89 mins, for example (yamaha 8824).
  5. ExCyber

    ExCyber Staff Member

    Also, it should be noted that the usable capacity of a CD-ROM depends on what mode is used - Mode 1 offers an extra (above and beyond that used for audio) error correction layer, but only provides 2048 bytes in each sector for your data. Mode 2 Form 2 offers 2336 (IIRC) bytes of user data but sacrifices most (if not all) of the error correction info that Mode 1 has. Audio tracks get to have 2352 bytes per sector of data, since they have no additional error protection. Theoretically a bit more information could be crammed into subcode areas, but AFAIK there is no standard way of doing so, and doing so might break existing standards. The advertised data capacity for CD-ROM is typically based on Mode 1 capacity.

    Edit: I just plugged the numbers into calculator, and if the 900MB figure is indeed based on Mode 1, and I didn't screw up my math, then these discs would have just over 1GB usable in Mode 2 (assuming that they can actually be burned, of course :))

    (Edited by ExCyber at 7:24 am on Oct. 30, 2001)
  6. Quadriflax

    Quadriflax New Member

    I saw GD-ROM writers up for auction on eBay a while ago. I don't know anything about them nor where you'd get blanks, but if that wasn't a scam they do exist.

    Also, where do they sell the 700+ MB CDRs? I've known about them and I've seen info on them here and there, but I can't find a place to buy them (not very good at locating things I must admit). I'd like to see what my Plextor is capable of writing on them. Which raises a question. How do you know? Do you just burn 900 MB and see where it stops or is there some other way?

    (Edited by Quadriflax at 10:28 am on Oct. 30, 2001)
  7. IceDigger

    IceDigger Founder Staff Member

    the gdrom writers were a scam.

    700 MB are normal 80 min blanks.

    you can get 90 and 99 min blanks in most stores.. the small electronics shop across the street here got them with the normal blanks.

    as for testing the limit, nero works well.. just change the "max over burn to" setting to 99 mins and burn 900 megs to see how much works, and most importantly, how much is readable (you might end up with bad data at the end).
  8. Quadriflax

    Quadriflax New Member

    Bummer about the writers, too good to be true I guess :)

    And I can't find anything larger than 700 MB around here. I've looked in quite a few places when I'm out and about. Maybe they're in some of the smaller, locally owned stores. Anyone know of a place online that sells them? I've poked around and haven't turned anything up, but I don't do a whole lot of shopping on the net so I don't know anything but the big names. I don't really need them, just curiosity. Kinda reminds me, I'd should get some of those tiny 250 MB or so CDs, they're neat (I'm a dork, I know).
  9. Supergrom

    Supergrom Member

    hehe, i have some mini cds. I think they are a little smaller than 250. im pretty sure its 20 or 21 minutes, so im not sure how much data that is, the package doesnt say.
  10. Shaneus

    Shaneus New Member

    Heres what i've read: (from what i can remember)

    nb. I dont want to do this, was only a curiosity

    Apparently if u get the DC coders cable, and some software on the DC, it will stay in the DCs memory, and u wait till the screen turns blue (or some colour)

    u put ur disc in, and it reads it and transfers it thru the serial cable

    i think what the l33t war3z d00dz do is actually remove music from the game, and lower the quality of the video so it will fit on a 650mb disc

    ie. most of the movies are gone in THPS2, and theres only half the music tracks in VOOT

    but seriously tho, i dont own any of these kinda games... i borrowed one once, and the way the laser was making those noises... never again :(
  11. Fabrizo

    Fabrizo New Member

    Mini disks may not hold much compared to normal disks, but they somehow look "neet" to me. Also, whats this about 900mb burnable disks? I have never seen anything higher then 700mb around where I live, and have not heard, except from you now, that there were any past 800mb. If disks that can hold so much exist, why arn't they as widly maketed like 700mb ones?

    (Edited by Fabrizo at 11:34 pm on Oct. 31, 2001)
  12. IceDigger

    IceDigger Founder Staff Member

    cause anything above 700 MB can not be burnt by all burners, and the amount they can burn differs bigtime. some burners can only do 83 mins, others 90, others 99, some 95, etc.. there's simply no way to tell how much everyone can use.
  13. FLEABttn

    FLEABttn New Member

    There are aproximately 3 ways of getting that data off the disc.

    The 2 ways I know for a fact work are:

    1: Coders Cable/Serial Cable

    2: Broadband Adapter

    The 3rd way which I hear works (people say it works, and other people agree, and nobody contests the statement) is by creating a disc with a fake TOC, and messing around and disassembling your CD-ROM drive.
  14. Gear

    Gear New Member

    I tought the 3rd way works if your CD-ROM is compatible with 120 min cds; no matter if you modify it or not. But I think you have to modify your CD-ROM to force it to read 120 min cds.

    Someone knows about this modification?
  15. Quadriflax

    Quadriflax New Member

    Never even heard of a 120 Min CD. But I found some info on the 900MB ones. Looks like you can actually damage your player and/or recorder in a worse case scenerio.

  16. Gear

    Gear New Member

  17. IceDigger

    IceDigger Founder Staff Member

    it's impossible to modify a cd drive to read gdroms, any and all info about that was fake.
  18. behelit

    behelit New Member

    th GD-rom actually is a normal cd but the data is burnt differently

    i cant remember exactly but its sumtin like the music is burnt on the out sector normally but the data is compressed on the inner layer

    also hardly anygame made for dc so far is 1gb

    crazy taxi without all movies and music was 80mg

    most games are 300 - 600 mg

    but the cd's are filled with junk or empty data to fill the cd

    thats why burnt DC games need a dummy file to fill the cd to run


    i dont burn DC games

    i buy them...
  19. Fabrizo

    Fabrizo New Member

    I burned on DC game before, and I quickly learned it is very hard on your DC. Unless you burn it in just such a way, the disk can wear out your dc's disk drive in a matter of days. I will never burn another DC game again, its not worth harming the system.

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