80 Minute CD holds 700MB but you can get 800MB on it!?!?!?

[Trenton_Net]

Hi,

I noted some people said you can get 800MB on a 80 Minute CD. I thought there was a max of 700MB?

Which mode do you burn to get this extra space? Im asuming the mode changes the formating of the disk, so you can squeeze more space out of it.

Thanks,

[VidGuy]

Yes, you record in Mode 2/XA mode, which is the mode that VCDs and SVCDs are recorded in. In that mode - 1 sector is 2324 bytes instead of 2048 bytes (Mode 1 uses the extra bytes for error recover, Mode 2 does not).

[jjo]

Does the burner software (like Roxio EasyCD or Nero) know you are using a 700MB cd as opposed to a regular 640MB CD, or do you have to "tell it"?

[Graham Meredith]

It seems to automatically sense it. I have a really old Ricoh MP6200A burner, and I assumed it couldn't write more than 650MB, even to 700MB disks, because they weren't around then and it may not have been physically designed for them. I've since started using them for 650MB burns (700MB are easier to get now), but still using my old Ezy CD 3.5c to burn them, and it would tell me that my 700MB files were larger than 650MB and that it would not allow the write. But I recently got Ezy CD 4, and it allows it, and I've successfully burnt VCD's (using the "Video CD" menu) with source mpg file sizes of 806MB burning to 695MB actual file size on the disk. So it seems its a software thing. Ezy CD 4 does them, and I'm pretty sure any Nero 5 version does them.

Graham

[willem]

The number of megabytes you can write to CD depends on the filesystem used and how much error correction info is stored. Less error correction stored on CD means more room for data. But of course it's more likely to show read errors when it's dirty or scratched.
It's like a standard floppy disk (remember those?). They can store 2 MBytes. A standard format leaves 1.44 MBytes. There are also formatting options with less error correction info enabling writing of 1.7 MBytes to a floppydisk.