I have inherited a free receipt printer with a cash drawer. It uses a parallel interface, and there appears to be no know driver for it. (It's a Star SP-200.) A simple Python script printing "Hello World!^G" successfully prints and opens the cash drawer. However, choosing the Generic Raw Queue or the Generic Text-Only printers still appears to send PDF to the printer.

This is with Ubuntu 13.10, and the latest OpenERP from the repository (7.0-20140326) as well as the most recent PoS.