bogus

[ORG 0x100]

jmp @Principal

@WriteCh:

pusha
push es

mov dx, 0xB800
mov es, dx
mul ah
mov edi, ax
mov ah, bh
mov al, bl
stosw

pop es
popa
ret

@Principal:

mov ah, 0
mov al, 20
mov ah, 40
mov bh, 0x2F
mov bl, 'A'
call @WriteCh

@Fim:

mov ax, 0x4C00
int 0x21