Heres my code
`mov ah, 0x0e
mov al, ‘a’
int 0x10
bits 16
org 0x7c00

boot:
mov si, message ; Point SI register to message
mov ah, 0x0e ; Set higher bits to the display character command

.loop:
lodsb ; Load the character within the AL register, and increment SI
cmp al, 0 ; Is the AL register a null byte?
je halt ; Jump to halt
int 0x10 ; Trigger video services interrupt
jmp .loop ; Loop again

halt:
hlt ; Stop

message:
db “CodeNameMudOS 1.0 Developement Beta”, 0

; Mark the device as bootable
times 510-($-$$) db 0 ; Add any additional zeroes to make 510 bytes in total
dw 0xAA55 ; Write the final 2 bytes as the magic number 0x55aa, remembering x86 little endian`

enter image description here
I tried to do it again but it just shows the same error