Date: Sun, 23 Sep 2001 18:50:50 -0500 From: David Kelly <dkelly@hiwaay.net> To: swear@blarg.net (Gary W. Swearingen) Cc: freebsd-questions@FreeBSD.ORG Subject: Re: Why is ISO CD one block bigger than ISO file? Message-ID: <200109232350.f8NNooG07089@grumpy.dyndns.org> In-Reply-To: Message from swear@blarg.net (Gary W. Swearingen) of "22 Sep 2001 12:41:50 PDT." <pv4rpvypvl.rpv@localhost.localdomain>
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Gary W. Swearingen writes: > I've got a 4.4R ISO file. Size is 324368*2048. I did > "burncd -f /dev/acd0c -s 8 data 4.4R.iso fixate" and then did > "dd if=/dev/acd0a bs=2k | wc" which showed the CD was one 2048-byte > block bigger than the ISO file. I used "dd" and "md5" to verify that > the first 324368 blocks of the CD were the same as the ISO file. > Why the extra block? Last time I tried that with a Philips IDE 8/4/32 drive it came up one block short. That and other problems with the drive convinced me to be happy to pay Circuit City's 15% restocking fee. Believe the issue was whether or not an EOF was to be signaled by the device to the driver on reaching the end, or on attempt to read past the end. Some brands respond differently. Would be worth investigating the quirk table to see how yours is used. Then again, I don't know there is an ATAPI quirk table for CD drives. Bought a SCSI HP 9200 elsewhere and dd correctly read the original image. Have not tried it lately. -- David Kelly N4HHE, dkelly@hiwaay.net ===================================================================== The human mind ordinarily operates at only ten percent of its capacity -- the rest is overhead for the operating system. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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