; boot.asm - prints 'A' and halts
BITS 16                  ; 16-bit real mode
ORG 0x7C00               ; boot sector load address

start:
    mov ah, 0x0E         ; teletype output BIOS function
    mov al, 'A'          ; character to print
    mov bh, 0x00         ; page number 0
    mov bl, 0x07         ; text attribute (light grey on black)
    int 0x10             ; BIOS video interrupt

    cli                  ; disable interrupts
hang:
    hlt                  ; halt CPU
    jmp hang             ; infinite loop

; fill the rest of the sector with zeros
times 510-($-$$) db 0     

; boot signature (2 bytes)
dw 0xAA55