{/************************************************************************/}
{/* Get configuration switches the external register			*/}
{/* This is a dangerous routine because it turns off video clock	*/}
{/************************************************************************/}

procedure read_switches;
var
i,bits,switches,old_mode : word;
begin
	switches := 0;
	old_mode := get_mode;

	{/* Writing to 3C2 disables video !				*/}

	write_register($3C2,$C);	{/* Select interpretation	*/}
	bits := read_register($3C2);	{/* Get external register	*/}
	bits := (bits and $10) shr 4;	{/* Isolate switch bit		*/}
	switches := bits or switches;	{/* Add bit to switch		*/}

	write_register($3C2,$8);	{/* Select interpretation	*/}
	bits := read_register($3C2);	{/* Get external register	*/}
	bits := (bits and $10) shr 3;	{/* Isolate switch bit		*/}
	switches := bits or switches;	{/* Add bit to switch		*/}

	write_register($3C2,$4);	{/* Select interpretation	*/}
	bits := read_register($3C2);	{/* Get external register	*/}
	bits := (bits and $10) shr 2;	{/* Isolate switch bit		*/}
	switches := bits or switches;	{/* Add bit to switch		*/}

	write_register($3C2,$0);	{/* Select interpretation	*/}
	bits := read_register($3C2);	{/* Get external register	*/}
	bits := (bits and $10) shr 1;	{/* Isolate switch bit		*/}
	switches := bits or switches;	{/* Add bit to switch		*/}

	write_register($3C2,$A6);	{/* Select interpretation	*/}

	set_mode(old_mode);		{/* Restore 3c2 to proper value	*/}
	writeln('Switch setting is ', switches, ' (decimal)');
end;