Message-ID: <01FD6EC775C6D4119CDF0090273F74A4021FE2@emwatent02.meters.com.au> From: "da Silva, Joe" To: "'opendos AT delorie DOT com'" Subject: RE: [ot] disk geometry mismatch? Date: Wed, 14 Mar 2001 18:07:53 +1100 MIME-Version: 1.0 X-Mailer: Internet Mail Service (5.5.2448.0) Content-Type: text/plain Reply-To: opendos AT delorie DOT com I always recommend to read : "http://web.inter.nl.net/hcc/J.Steunebrink/bioslim.htm" Joe. > -----Original Message----- > From: Rob McGee [SMTP:i812 AT iname DOT com] > Sent: Wednesday, 14 March 2001 17:29 > To: opendos AT delorie DOT com > Subject: [ot] disk geometry mismatch? > > ** This isn't even remotely DR-DOS related. But if anyone can figure out > ** this problem, it would be you people. :) Replies off list would be > ** very much appreciated. (Or on list if you think it's interesting.) > > This is indeed a puzzlement. Our eldest kid got a gift computer. It > cruised along okay for months, despite a few warning signs: RAM failed > POST, unable to warm reboot, didn't report disk size and free > information as an SMB share. But it would easily go at least 1-3 days > between reboots, and considering it was running Win95 (OSR2) that is not > too bad. So I blew off doing anything about the problems. > > Sometime yesterday, while unattended, it died. I had seen it running a > screensaver in the morning. She came to do something in the afternoon > but got no picture. When she turned it on for me I could tell it wasn't > booting: no video initialization, not even a beep code error. > > I tried disconnecting everything but the video: cards, power & interface > cables. I swapped the RAM. I swapped the video card. I swapped the CPU > (yes, absolutely sure the jumpers were correct.) Still no flicker, still > no beep. 'E's pinin' for the fjords. Beautiful bird, the Norwegian Blue. > > I put most of the same peripherals on a different motherboard with a > different CPU and RAM. In getting it to work, physically, I found I > could no longer access the hard drive. It's a WDC AC35100L which is > C/H/S 10672/15/63, LBA'ed to 627/255/63. Identify drive from a Linux > boot message says "10085040 sectors (5164MB)". > > DOS fdisk said: "C: partition 1, active, PRI DOS type, no volume label, > 4918MB, system unknown, usage 100%." It goes on to say the total disk > space is 4910MB, 8 less than the partition. That sounds odd. Figuring > "(sectors * 512) / 1024^2" I get 4924.3359MB. > > I had a CD of Norton Util. 95 v. 2 (FAT32-aware) and tried ndd.exe. It > offered to try to recover a partition of 812MB. I declined the offer and > tried diskedit.exe instead. The first 63 sectors were all 0's. (63 spt, > of course. Is that normal?) > > The 64th sector showed what looked to my untrained eye like some > filesystem information. There was a string "FAT32" and the volume label > as it was before the crash. I asked diskedit to try to create a virtual > filesystem of this, and again, it offered something in the 800MB range. > Furthermore it said it would be FAT16. But that's not right, it was all > in one big FAT32 partition. > > I tried changing some of the parameters around, but could not find > anything that worked. Since I really don't know what I am doing I feel > like I'm looking for the proverbial needle in a haystack. Somewhere > along in there I tried "fdisk /mbr" too. > > Finally this afternoon I came up with the hypothesis of a disk geometry > mismatch. That some parameters had been manually entered in the dead > motherboard's CMOS settings, and they weren't quite correct, but close > enough that the drive went along with it. > > Does this hypothesis sound right? If so is there anywhere I might be > able to find a clue about the disk geometry parameters used? I'm afraid > that my "fdisk /mbr" might have rendered the thing unbootable though. > > It's nothing major, but if there's any way to recover this I sure would > like to do it. > > If you read this far, thank you for your time. If not, I'm sorry for the > disruption. :) > > Rob - /dev/rob0