unsigned char APMSoftPowerOff(void)
{
    asm{
        push AX
        push BX
        push CX
        mov AX, 0x5300    // 1: APM install check
        mov BX, 0x0000
        int 0x15
        jc APM_err
        mov AX, 0x5301    // 2: APM interface connect
        mov BX, 0x0000
        int 0x15
        jc APM_err
        mov AX, 0x530E    // 3: APM driver version
        mov BX, 0x0000
        mov CX, 0x0102    // APM v1.2 (CH=01, CL=02)
        int 0x15
        jc APM_err
        mov AX, 0x5307    // 4: APM set power state
        mov BX, 0x0001
        mov CX, 0x0003    // power off
        int 0x15
        jc APM_err
        mov AX, 0x5304    // 5: APM interface diconnect (only if power off error)
        mov BX, 0x0000
        int 0x15
        pop CX
        pop BX
        pop AX
    }
    APM_err:
    return(1);
}