search for: 440th

...*not* have the boot flag set, but hda1 *will*. So to test altmbr I: - boot into linux and do: dd if=altmbr.bin of=/dev/hda bs=1 (440 records are output) - via fdisk: affirm the boot flag for hda1 - via fdisk: remove the boot flag for hda5 - via DOS (ye olde Norton Disk Editor no less): I edit the 440th byte of the MBR (that is, the first byte of the 4-bye disk signature field) to contain 0x05 and then I reboot, but get error msg noted above. FWIW in my testing I tried putting 0x00 thru 0x08 into not only that 440th byte (offset 439) but concurrently into bytes 438, 439 and 441 for each of m...

.... Enter syslinux's 'altmbr.bin'. The logic of controlling which partition syslinux boots into is changed from being based on the boot flag in the partition tables, to being a whatever partition number is specified by a single 'configuration' byte in the MBR, specifically the 440th byte (the one right before the 4-byte disk_signature). So using this altmbr.bin lets us keep the active flag on hda1 (which keeps the TC boot loader happy) but lets us still initially boot into hda5 with the syslinux configuration. (Note that altmbr.bin doesn't seem to detect multiple boot...