1. This forum is in read-only mode.

Download size help please

Discussion in 'Technical Help' started by david24872450, Jun 7, 2009.

Thread Status:
Not open for further replies.
  1. david24872450

    david24872450 Member

    Dear all, sorry if this sounds dumb but i'm not the most technically gifted when it comes to PCs etc - i've downloaded a rom which says it is 27mb but when i put it on MicroSD/DS is shows as 64mb, clearly more than I thought - am I doing something wrong? Thanks in advance, Dave.
     
    david24872450, Jun 7, 2009
    #1
  2. Loonylion

    Loonylion Administrator Staff Member

    No. Rom sizes have to conform to a power of 2 size, meaning the size of the actual game is somewhere between 32MB and 64MB. It is then padded with rubbish data to make it up to the nearest power of 2 size, in this case 64MB. Since this data is just a repeated sequence, it compresses very easily, and some of the game content also compressed, to get the downloaded file size to 27MB. Extracting the game from the rar file reversed this compression.
     
    Loonylion, Jun 7, 2009
    #2
  3. david24872450

    david24872450 Member

    Thanks Loonylion, I think I understand? So can I add it to the MicroSD as 27mb or does it have to stay as the 64mb? If so, how do I do it? Thanks again,
     
    david24872450, Jun 7, 2009
    #3
  4. sexywogboy

    sexywogboy Well-Known Member

    Send it to the MicroSD as 64mb
     
    sexywogboy, Jun 7, 2009
    #4
  5. 1prinnydood

    1prinnydood Guest

    You are not doing anything wrong. DS Roms contain padding so that the file size conforms to the internal memory size of the original game cart. As you downloaded a compressed .rar file this extra padding was removed but when you decompress it is restored again. In order to save space on your flash cart you can remove this extra padding by using a trimmer program like this http://techsuki.net/nintendo-ds-rom-trimmer/
    This will remove all the extra stuff you do not need to play the game. Simply trim the .nds file before you save to your flash cart.
     
    1prinnydood, Jun 7, 2009
    #5
  6. Loonylion

    Loonylion Administrator Staff Member

    You cannot add it in its compressed form as flashcarts cannot read compressed archives. You can trim the rom, which removes the rubbish data, but the amount of space that saves will vary between games (in your example case could be anything between a couple of MB and 31MB), and trimming has been known to cause issues with some roms in rare cases.
     
    Loonylion, Jun 7, 2009
    #6
  7. david24872450

    david24872450 Member

    Thanks guys, i've just tried the Techsuki link which has removed a few MB (all counts) so thanks for this. The upshot, I guess, is everyone will add them to the SD at a larger size tha n originally downloaded? Thanks for all your help.
     
    david24872450, Jun 7, 2009
    #7
  8. anandjones

    anandjones Well-Known Member

    It trims as close as possible to the recorded hash.
     
    anandjones, Jun 8, 2009
    #8
Thread Status:
Not open for further replies.