>Is there a way to tell where the input came from: scanner or keyboard?

See my message#1089012, the "special" character I describe, can also be used to determine whether the input comes from the keyboard or from the harcode reader. The "special" character can be any keyboard combination, like alt-2, so in theory there's always the possibility that people can enter the same combination from the keyboard. If you need to make this completely foolproof, you can use a special character and a timer to check how fast the character comes, only Calvin Hsia types fast enough to compete with a barcode reader. :-)