From: "Adam Schrotenboer" Newsgroups: comp.os.msdos.djgpp Subject: Re: Bios Geometry Date: Wed, 1 Jul 1998 16:33:50 -0400 Organization: Triton Technologies, Inc Lines: 53 Message-ID: <6ne6fb$pko$1@news1.triton.net> References: NNTP-Posting-Host: hol-ppp193.triton.net Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit To: djgpp AT delorie DOT com DJ-Gateway: from newsgroup comp.os.msdos.djgpp Precedence: bulk I'm no expert, but I have two guesses, though intertwined. First, many HD's have a "diagnostic" cylinder, which allows low-level testing and formatting of a cylinder w/o losing the data on the drive. Second, on most HD's the partition doesn't include the "diagnostic" cylinder. biosdisk may be returning data on the partition, not the physical drive. MetcalJM AT utrc DOT utc DOT com wrote in message ... Hi, I was wondering if anyone can explain a strange phenomenon to me. I am using the cmd 8 to the "int biosdisk" library function (header in ) to retrieve the geometry of my hard drive. What I receive back, tells me that my geometry is: cyls: 522 (return val 521 + 1 for starting at 0) heads: 64 (return val 63 + 1 for starting at 0) secs/track: 63 (return val 63 + 0 for starting at 1) I've used two other utilities to confirm these parameters. They report the correct number of heads and secs/track, however, the number of cylinders is off by 1. (They are reporting 523). Other calculations based on the size of my partitions also seem to agree with the 523 number. Can anyone tell me why biosdisk, which I understand uses the DOS INT 0x13 call, is reporting 1 less than the proper number or cylinders? Here's more info on my system and gcc: My BIOS uses LBA, so the real geometry is c: 2095 h: 16 s/t: 63 b/s: 512 gcc version 2.8.1 Thank You for any ideas you can provide. Reagrds, JM > ------------- > Jeffrey M. Metcalf > United Technologies Research Center > metcaljm AT utrc DOT utc DOT com > (860) 610-7576 > >