>Got one of those old com port activated cash drawers from an existing customer but he couldn't provide the documentation on the codes to send to kick open the drawer.
>Are there any standard command to use to kick open the drawer?
>Yau

If none of the other suggestions works, I also had a situation with such a drawer. The drawer (back by the power cord to the drawer) had a bank of dip-switches (1-8)... Those were used to identify the special character to activate opening the drawer. So, you could set up printing something like chr(251) (a non-visible character to the printer) and that would trigger it. The dip-switches obviously were based on binary equivalent representation of the number of the CHR(?) you were trying to send. I think (as Shafid simulated), you had to do the special character like 3 times before it would activate, in case such a special character was actually part of the intended document that it wouldn't falsely interpret that and open the drawer.

Also... have you tried to locate and Google the model of the cash drawer and try to get a copy of a users manual on it?