a20.asm

来自「实现了分段分页」· 汇编 代码 · 共 16 行

OPEN_A20    PROC            ;打开A20地址线
            PUSH AX
            IN   AL,92H
            OR   AL,2
            OUT  92H,AL
            POP  AX
            RET
OPEN_A20    ENDP
CLOSE_A20   PROC             ;关闭A20地址线
            PUSH AX
            IN   AL,92H
            AND  AL,0FDH
            OUT  92H,AL
            POP  AX
            RET
CLOSE_A20   ENDP