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>