Serial Printer Control

Thanks for the help. That was what I was thinking of when I posted the request, but, on more reflection, I need something different. I should have said that I want to change the parameters in an Apple Laserwriter IIg printer. The documentation says that certain (6-9) switch settings on the printing board can be set with user-configurable communication options, but the docs don't say how to do this. They do mention that the baud rate can be set up to 57.6k, which is what I would like to do. Currently, I am limited to 19.2k, by the switch settings. What I need to know is how to send the commands to the printer to change the communication settings for a certain switch. I would assume it would be via a postscript file. Thanks for the help!