The @_mc680x0 variable determines if a Motorola 680x0 processor is being used. When the variable is not true, it is defined as NaN.
<html>
<script language="JScript">
<!--
@if (@_mc680x0)
alert("You are using a Motorola 680x0 processor.");
@else
alert("You are NOT using a Motorola 680x0 processor.");
@end
-->
</script>
</html>