ASSEMBLY AND BOOT LOADERS AND SHIT

k, so my program needs to boot a hard disk. how the fuck do i do that.
isn't it enough that i read the boot sector to 07c00h, set dl, and jmp there? doesn't seem to work. shit

>>9
oh, that's not how i meant. i guess i should have explained it better.
so, i've got a program on a 1.44 floppy. it boots up and does some shit, but then i want it to load another operating system from another disk, as if it was loaded by the bios. as far as i know, all the bios does after the post is load the boot sector, set dl to the disk number, and transfer control to the program, but when i do that it doesn't seem to work. what else do i need to do? halp