GeoDsp1S is a one-sector variant containing all code in one sector that is intended to test behavior with a typical MBR/partition table layout. A partition table should be written after writting an image.
GeoDspMS is a multi sector variant intended to look like Syslinux installed on a file system on the raw device (as opposed to a file system within a partition).
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+GeoDspMS can also be used to attempt to make the boot sector look like a normal file system's boot sector (ie FAT12/FAT16/FAT32). In order to do this, you must first save a portion the existing boot sector (the majority of the BIOS parameter block).
+ dd bs=1 skip=3 count=87 if=/dev/sda of=sda.bpb
+ dd conv=notrunc if=geodspms.img of=/dev/sda
+ dd conv=notrunc bs=1 seek=3 count=87 if=sda.bpb of=/dev/sda
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