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Unformatted text preview: Jelena Mamenko Operating Systems Lecture Notes on Operating Systems 56 0x3e 448 Operating system boot code 0x1FE 2 End of sector marker (0x55 0xAA) The boot sector is portrayed here as found on e.g. an OS/2 1.3 boot diskette. Earlier versions used a shorter BIOS Parameter Block and their boot code would start earlier (for example at offset 0x2b in OS/2 1.1). 22.214.171.124 Exceptions The implementation of FAT used in MS-DOS for the Apricot PC had a different boot sector layout, to accommodate that computer's non-IBM compatible BIOS. The jump instruction and OEM name were omitted, and the MS-DOS filesystem parameters (offsets 0x0B - 0x17 in the standard sector) were located at offset 0x50. Later versions of Apricot MS-DOS gained the ability to read and write disks with the standard boot sector in addition to those with the Apricot one. DOS Plus on the BBC Master 512 did not use conventional boot sectors at all. Data disks omitted the boot sector and began with a single copy of the FAT (the first byte of the FAT was used...
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This note was uploaded on 12/29/2011 for the course CSE 362 taught by Professor Mavin during the Spring '09 term at SUNY Stony Brook.
- Spring '09
- Operating Systems