grittykitty wrote:if i remember correctly, vampire chronicle's image was 775 megs. burns and works perfectly on 80-min cd-r's. the only image i've seen that won't fit on a regular cd-r is mozgus's rip of project justice on underground gamer (1 gig image?)... and damn, i really hope someone can do a good downsampling of that
Mozgus's rip is a straight rip for people who want the full image. Such as for the DC emulator... or to choose to downsample it themselves or what not (I don't know his full intentions of the image).
But yes, you have to select over burn. First off a 700MB CD-r with can fit the equivalent of about 737 Megabytes of information with long (2352) error correction. (shortened error correction can store more) This 737 Megabytes is actually called Mibibytes or MiB. Due to confusion brought on by all the different adaptations of the definition of Megabyte for marketing reasons (basically to make it easier for consumers to understand sizes). Megabytes was never standardized and frequently relates to 1000 bytes per prefix. So 1000 bytes would be 1 kilobyte. It isn't ALWAYS done this way, but is done very often. SO the Mibi, Gibi, Tebi and so forth worth decided to describe ONLY those describing true binary counting. where kibi means 2^10 or 1024 bytes, and mibi stands for 2^20 or 1,048,576 bytes. blah blah blah.
The 700MB description of the disk reflects the amount of REAL binary bytes (700 MiB) on the disk with out describing the error correction. And 737 MB is the described actual size when comparing to things such as your Explorer that shortens it in the base 10 format. Blah blah blah... bunch of hubba lub.
ALSO (aside from overburned disks)
Now a sector of data which is 2048 bytes of real data (2 Kilobytes) is actually made up of 2352 bytes. When ripping a disk in RAW mode you rip this entire 2352 sector resulting in a file that seems a lot larger then it is. These error correction sectors must be ripped in the case of some data disks like video games or they won't function properly.
The size of the image file reflects this increased visible sector size and views it as just RAW binary so all bits are included in the factoring of the size. For instance a 700MiB disk has 360,000 2KiB sectors broken in 2352 bytes with error correction. This results in a disk that is actually 703.125 MiB in size (rounded to 700 for market reasons). Now when you rip the disk in RAW mode taking error correction with it each sector is now 2352 bytes large. 2352*360,000 = 846,720,000 bytes. Reduce to mega bytes and you have 807.5 MiB. This means a full disk can look as large as 807.5 MB when in an image! But respectively only has 703.125 MB of real useable data, the rest is just there so the CD-ROM can compensate for errors brought on by scratches, bumping and dust.
Some image formats also neglect empty 0 sectors and put smaller place holders there to reduce image size (why you usually don't see 800+ size images), but this process doesn't hide ALL the bytes.
Oh yeah and most CD burners consider 650 MB to be the limit of a disk even if it is an 80 min disk... so overburn is basically just filling a 700 MiB disk. It states when doing so that filling a 700 MiB disk may result in a disk that can not be read in all CD-ROMs because older CD-ROMs were made when 650 MiB disks were the only printed kind and the laser wasn't made to read out past that limit (i.e. the Sega CD... it only handles 650 MiB disks and is why all the images are equal to or less then that). Now don't confuse this with that actual disk... I'm talking the amount of data on it. Sega CD can handle 700MB disks as long as it isn't filled past 650MB.
Oh and one other thing, Audio usually isn't ripped raw and instead is ripped as audio and when reburned it given new error correction by the burner. Thus why it is believed that copying CDs reduces the quality as the error correction has been changed. You have to specially tell your CD-ROM to rip as RAW which most music CD ripping programs won't do.
So thusly, even though the image looks bigger then 700MB that is merely due to several factors causing it. Misconception of what the Megabyte is brought on by marketing, the fact that people forget about error correction code length, and that disk were actually intended to only be 650MiBs in size.