Analysis of information sources in references of the Wikipedia article "Master boot record" in English language version.
Every operating system includes tools to manage MBR partitions. Unfortunately, every operating system handles MBR partitions in a slightly different manner.
0x7C00 in x86?". Glamenv-Septzen.net. Archived from the original on 2017-08-24. Retrieved 2011-05-04.[…] SYS […] /O[:nnn] Override IPL reported boot drive unit (n=0..126, 128..254). […] Preparing target disk... Choosing FAT12 CHS Boot Sector (requires IPL to report boot unit). Treating target as diskette or superfloppy medium (boot drive unit 0). Writing new Boot Sector... […](NB. SYS writes volume boot records rather than master boot records, but their incoming register interface is similar (with extensions) since they could both be loaded initially by the underlying system.)
When we added partitions to this NEC table, the first one was placed at offsets 0x01EE through 0x01FD and the next entry was added just above it. So, the entries are inserted and listed backwards from that of a normal Table. Thus, looking at such a Table with a disk editor or partition listing utility, it would show the first entry in a NEC eight-entry table as being the last one (fourth entry) in a normal Partition Table.(NB. Shows an 8-entry partition table and where its boot code differs from MS-DOS 3.30.)
Matthias [R.] Paul writes: "[…] PTS-DOS [uses] a special fifth partition entry in front of the other four entries in the MBR and corresponding AAP-aware MBR bootstrap code. […]"
Some OEM systems, such as AST DOS (type(NB. NEC MS-DOS 3.30 and AST MS-DOS partition tables with eight entries are preceded with a signature14hex) and NEC DOS (type24hex) had 8 instead of 4 partition entries in their MBR sectors. (Matthias R. Paul).
A55Ahex at offset 0x017C.)Matthias [R.] Paul writes: "[…] PTS-DOS [uses] a special fifth partition entry in front of the other four entries in the MBR and corresponding AAP-aware MBR bootstrap code. […]"
Some OEM systems, such as AST DOS (type(NB. NEC MS-DOS 3.30 and AST MS-DOS partition tables with eight entries are preceded with a signature14hex) and NEC DOS (type24hex) had 8 instead of 4 partition entries in their MBR sectors. (Matthias R. Paul).
A55Ahex at offset 0x017C.)When we added partitions to this NEC table, the first one was placed at offsets 0x01EE through 0x01FD and the next entry was added just above it. So, the entries are inserted and listed backwards from that of a normal Table. Thus, looking at such a Table with a disk editor or partition listing utility, it would show the first entry in a NEC eight-entry table as being the last one (fourth entry) in a normal Partition Table.(NB. Shows an 8-entry partition table and where its boot code differs from MS-DOS 3.30.)
0x7C00 in x86?". Glamenv-Septzen.net. Archived from the original on 2017-08-24. Retrieved 2011-05-04.[…] SYS […] /O[:nnn] Override IPL reported boot drive unit (n=0..126, 128..254). […] Preparing target disk... Choosing FAT12 CHS Boot Sector (requires IPL to report boot unit). Treating target as diskette or superfloppy medium (boot drive unit 0). Writing new Boot Sector... […](NB. SYS writes volume boot records rather than master boot records, but their incoming register interface is similar (with extensions) since they could both be loaded initially by the underlying system.)