DOCUMENT:Q97819 08-AUG-2001 [winnt] TITLE :Ambiguous References to Sector One and Sector Zero PRODUCT :Microsoft Windows NT PROD/VER:3.1 3.5 OPER/SYS: KEYWORDS:kbother ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Windows NT Server version 3.1 - Microsoft Windows NT Workstation version 3.1 - Microsoft Windows NT Advanced Server, version 3.1 - Microsoft Windows NT Workstation version 3.5 - Microsoft Windows NT Server version 3.5 ------------------------------------------------------------------------------- This article discusses some inconsistencies in sector numbering. Sector counting starts at 1 when referring to the physical disk geometry. The first sector is reference by head 0, cylinder 0, sector 1. When people refer to absolute sectors on a physical volume, however, they typically refer to sector 0 as the first sector. Many applications (for example, Norton Disk Doctor) refer to the first sector as sector 0. Other tools use different conventions. Documentation often references sector 0, as it is less ambiguous than using sector 1. Sector 0 is clearly the first sector, even if you disagree with the convention. Sector 1 is the first sector to some people, and the second sector to others. On a disk with 37 sectors per track, 8 heads, and 512 cylinders, Windows NT would look at the numbering as follows: absolute ----------------------------------------------- cylinder head sector sector address -------------------------------------------------- 0 0 1 0 0 0 2 1 0 0 3 2 0 0 4 3 0 0 36 35 0 0 37 36 0 1 1 37 0 1 2 38 0 1 36 72 0 1 37 73 0 2 1 74 0 2 2 75 0 7 36 294 0 7 37 295 1 0 1 296 1 0 2 297 511 7 36 151550 511 7 37 151551 Additional query words: prodnt sector zero one 0 1 one-based 1-based zero- based 0-based ====================================================================== Keywords : kbother Technology : kbWinNTsearch kbWinNTWsearch kbWinNT350search kbWinNTW350 kbWinNTW350search kbWinNTW310 kbWinNTSsearch kbWinNTS350 kbWinNTS310 kbWinNTAdvSerSearch kbWinNTAdvServ310 kbWinNTS350search kbWinNTS310search kbWinNT310Search kbWinNTW310Search Version : 3.1 3.5 ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY. Copyright Microsoft Corporation 2001.