Vista on a CD but how big is a CD?

[Jeronimo]

I found some files under sources\license referring to other Vista versions as well. I removed these BurnOn CD&DVD does not report that the disc is too small. Now trying to burn (image) with vLite and that goes without an issue.

Maybe the error can be renamed or is it a general errornumber? Maybe even check up front if image/files fit the disc?

[WMGarab]

Hello everyone. I know this is an old thread, but I thought I'd clear a few things up real quick.

CDs hold approximately 700 MiB of data. No, MiB is NOT a mistype. MB measures data in 10^x factors, and MiB measures it in 2^x factors. It was recently adopted (few years ago) and is unfortunately SLOW to catch on. Before the adoption of this new symbol, pepole would get 2^x and 10^x confused all the time. For example, Hard drives measure capacity in 10^x quantities...320 GB = 320,000,000,000 bytes, or 298.0232 GiB. Are you getting robbed of that extra data? No, because it was never really there. It was just measured differently. BOTH methods of measuring capacity are perfectly valid, and in fact, the 10^x measurements are probably closer to normal (hunan) ways of measuring things, since they are measured in base 10 numerals. The 2^x measuring system is obviously a binary system adopted in computer software because computers (obviously) measure amounts in binary. The conversion between b 00010000 00000000 00000000 (1 MiB, 1,048,576 bytes) and b 00001111 01000010 01000000 (1 MB, 1,000,000 bytes) requires a little math, and a bit of extra programming. So programmers decided that 1024 bytes (b 00000100 00000000 ) is really close to 1 KB (b 00000011 11101000), so they just used the 2^10 to ~ equal 1 KB. Back when this decision was unofficially made, we didn't even had DOS yet, and data capacity was measured in kilobytes, not gigabytes, so the difference was negligible. The tradition carried on in computer software, and the hardware manufactures had no requirements to use 2^x measuring, so they stuck with the "real" 10^x measuring that has always been around. When hard drives made it to the Megabyte range, each reported MB would be undercounted by 48,576 bytes, again not that big a deal, so no changes were made. Now that we see GB drives, and even TB now, the difference isn't so small anymore! 1 GB is 73,741,824 bytes less than 1 GiB, and 1 TB is 9,951,162,7776 bytes less than 1 TiB!

So you see, it's just the way the capacity is measured that shows a difference.

Now, with the CD again...

CDs actually hold ~ 74 Mins of audio, or 650 MiB of data. The 700 MiB CDs you buy require a little explanation.

The CD standard allows a certain tollerance for how far apart the "grooves" are on a cd. On average, the groove spacing, signal rate, and rotation rate of the CD will approximately = 660 MiB - 670 MiB of data, but to be SAFE, manufactures limit it to 650 MiB, that way you won't run out of grooves while burning, or hit a defective groove near the edge of the disc.

700 MiB CDs compress those grooves to the ABSOLUTE MINIMUM Tolerances allowed by the CD standard, and with the extra grooves you can fit at the end, you end up with about 720 MiB to 730 MiB of space . Again manufactures play it safe, and report 700 MiB for simplicity, but with "overburn" software, you can try to use that extra little bit the otherwise leave out, and you can sometimes get 5 - 10 MiB more data (or more) on the disc. This runs the risk that medium after the 700 MiB may be defective in some way, and you will lose data though, so be CAREFUL with this.

Now, remember, CDs have error correcting codes encoded with the data, but audio cds have no such codes, so audio cds (A.K.A. XA-Mode data), can hold even more BUT! The slightest error on the disc corrupts data! With audio, this is no biggie, but with DATA, it is!

CD Audio runs at 44,100 samples a second, 16 bits / sample, 2 channels. 16 bits = 2 bytes, so 44,100 * 2 * 2 = 176,400 bytes / second. 74 mins = 4,440 seconds, so 4,440 * 176,400 = 783,216,000 bytes, or ~ 746 MiB of Audio data. An 80 Min CD (700 Mib) actually holds... 80 mins * 60 seconds/min = 4,800 seconds * 176,400 bytes/second = 846,720,000 bytes, or ~ 807 MiB of audio data.

If you could burn that much to the disc in Data, you'd have NO error protection, so a flake of dust, hair-line scratch, or slightly mis-calibrated drive will render corrupted data! Just stick with the 700 MiB/80 mins or 650 MiB/74 mins and call it a day, ok?

Have fun

-Warren

[WMGarab]

Sorry, forgot email notification on reply....adding now.