Legacy-boot Memes

Floppy's got some premium data sitting in sector zero and the BIOS just casually points to memory address 0x7c00 like it's been doing since 1981. No negotiation, no discussion. That's where your boot sector goes, kid. Always has been. The x86 legacy boot process loads your Master Boot Record to 0x7c00 in RAM and jumps to it. Why 0x7c00 specifically? Because some IBM engineer in the early 80s decided that's where it goes, and now we're all stuck with it. UEFI tried to escape this madness, but legacy boot just won't die. Bootloader devs know the pain. You write your beautiful assembly code, assemble it, and if you forget to tell your assembler about 0x7c00, your jumps go to the wrong addresses and the machine just sits there mocking you.