Rick, Thanks for your reply. Actually, this is an old Quantel printer that was working in some sort of "polling" environment. On the back of this beast I found one DB25 female connector and a label "HP 2563A". I assumed (don't we know that an assumption is a mother of a screw up :)) this is an HP printer. According to HP website they never made such a thing, although I found some postings in this newsgroup mentioning such a model. My task is to set the printer up on SCO UNIX. It sort of works but has a flow control problem. All the configuration of the printer suppose to be done by pressing "Config" and "F. Adjust" buttons on the front panel (which also has a 2 digit numeric display), referring to the printer manual for the meaning of the numbers displayed. Needles to say that I don't have a manual. I was wondering if somebody knows how to configure such a printer for software flow control (if it's possible at all). Thank you. "Rick Gilligan" <[log in to unmask]> wrote in message news:Pine.GSO.4.10.10006271334560.9941-100000@sun.case.net... > > Does anybody know how to set up HP 2563A (a very old dot matrix printer) > > for software flow control? > > I am assuming you have an HP 26067B RS-232/422 serial interface in the > printer. > > Set the low order bit in configuration byte 20 for xon/xoff flow control. > > Rick Gilligan > Senior Software Specialist > Computer And Software Enterprises, Inc. > E-mail: [log in to unmask] > >