/************************************************************************/
/* Get configuration switches the external register                     */
/* This is a dangerous routine do not run!                              */
/************************************************************************/

read_switches()
        {
        int     i, bits, switches = 0, old_mode;
        old_mode = get_mode();

        /* Writing to 3C2 disables video !                              */

        write_register(0x3C2,0x1C);     /* Select interpretation        */
        bits = read_register(0x3C2);    /* Get external register        */
        bits = (bits & 0X10) >> 4;      /* Isolate switch bit           */
        switches = bits | switches;     /* Add bit to switch            */

        write_register(0x3C2,0x18);     /* Select interpretation        */
        bits = read_register(0x3C2);    /* Get external register        */
        bits = (bits & 0X10) >> 3;      /* Isolate switch bit           */
        switches = bits | switches;     /* Add bit to switch            */

        write_register(0x3C2,0x14);     /* Select interpretation        */
        bits = read_register(0x3C2);    /* Get external register        */
        bits = (bits & 0X10) >> 2;      /* Isolate switch bit           */
        switches = bits | switches;     /* Add bit to switch            */

        write_register(0x3C2,0x10);     /* Select interpretation        */
        bits = read_register(0x3C2);    /* Get external register        */
        bits = (bits & 0X10) >> 1;      /* Isolate switch bit           */
        switches = bits | switches;     /* Add bit to switch            */

        set_mode(old_mode);             /* Restore 3c2 to proper value  */
        printf("\nSwitch setting is %x hex", switches);
        }