Date: Wed, 25 Dec 2002 03:27:12 +0100 From: Cliff Sarginson <cls@raggedclown.net> To: freebsd-questions@freebsd.org Subject: Re: How to find the capacity of CD? Message-ID: <20021225022712.GA31992@raggedclown.net> In-Reply-To: <20021224202010.GB53061@sub21-156.member.dsl-only.net> References: <20021224144253.GA156@dhumketu.homeunix.net> <20021224202010.GB53061@sub21-156.member.dsl-only.net>
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On Tue, Dec 24, 2002 at 12:20:10PM -0800, Nathan Kinkade wrote: > On Tue, Dec 24, 2002 at 08:12:53PM +0530, Shantanu Mahajan wrote: > > Hi! > > Is there any way to find out the capacity of blank > > CD before buring? > > > > Regards, > > Shantanu > > Shouldn't most CD-ROMs have around 700MB capacity? Are are you looking > to find out how much space is left on a partially written CD that has > not been fixated? > Mmm, doesn't it say on the sleeve. They vary in size, I think 640 and 700 are the 2 commonest. Thinking on my feet: - Do a test write first of what you want to put on it, may help you deduce the information. This pretends to do the write by not turning the laser on but otherwise going through the motions. - dd it into /dev/null until dd runs out of things to read (never tried this), - Put it in on a Windows System, I think "This computer" will tell you. - Use an elctron microscope and count the tracks. - Guess ? 700 is probably the most likely. This may not be much of a guarantee of getting the required space that will actually be used, CD-burners can handle a limited number of flaws and they use part of the CD to save this informationa. Which is why, by the way, copying a self-branded CD may fail, the error information for the CD you are copying from will be propagated, and the new CD you create may have it's own flaws. So you may run out of space for flaw recording. Another BTW, if you do not know it's capacity, then you probably don't know the speed at which it can be burnt safely, so you should probably use a low value <= 8X. Mmm. CD-R's are quite cheap you know...and make handy coasters, or when you are bored put one in a microwave oven. The result is spectacular, -- Regards Cliff Sarginson The Netherlands [ This mail has been checked as virus-free ] To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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