A hello world for an IBM PC compatible does not require much. Sadly UEFI has made everything exponentially more complex. If you want to be more minimalistic, th

A hello world for an IBM PC compatible does not require much. Sadly UEFI has made everything exponentially more complex. If you want to be more minimalistic, this also works with if the BIOS is newer than 1/10/86 (written in NASM syntax): [org 0x7c00] ; code offset xor dx, dx ; row 0, col 0 mov ds, dx ; set data segment to 0 mov ax, 0x1300 ; ah = 0x13 (write string), al = 0x00 (write mode) mov bx, 0x0007 ; bh = video page number (0), bl = attribute byte mov cx, 11 ; string len: 11 bytes mov es, dx ; ES:BP = pointer to string mov bp, message int 0x10 ; interrupt 0x10 end: ; do nothing to prevent crashing jmp end ; (cli & hlt also works) message: db "Hello world" times 0x01FE-($-$$) db 0 ; padding dw 0xAA55 ; boot sector signature