Printer does not print

Last Updated: 5th December, 1994

Symptoms
Spooler reports a printer as off-line or out of paper, or printer accepts data but never prints. Printer works fine under DOS or previous version of OS/2.

Hardware
Various printers, including an Oki OL400 (emulating HP LaserJetII), a real HP LaserJet II, HP PaintJet and PaintJet-XL, a HP Deskjet Plus, Panasonic models KX-P1124i and KX-P1123, an NEC SilentWriter 2/M90 (PS laser printer), and a Fujitsu 7100PS. Not to mention Lantastic printer support.

Problem
Under OS/2 2.x, the low-level printer support was interrupt driven, using IRQ7 for LPT1 and IRQ5 for LPT2. This was good (low overhead, good throughput) and bad (IRQ conflicts with SoundBlasters and other adapters, no choice on IRQ used, printer adapters and cables which worked under DOS might not under OS/2).

Beginning with OS/2 Warp Version 3, the OS/2 Development staff introduced a "stealth" enhancement: the default low-level printer support is now handled by periodically "polling" the printer port to see when it can accept the next character. This is good (allows a lot of printers, cables, and LPTx adapters to work under OS/2 that might not otherwise) and bad (increased overhead).

User feedback seems to be mixed. Some printers seem to work acceptably with OS/2 polled printing, some do not.

Fix
You can re-introduce interrupt-driven printer support by editing your OS/2 CONFIG.SYS file to add a /IRQ to the PRINT01.SYS or PRINT02.SYS statement. For more information, type HELP BASEDEV at a command prompt and then do a Search for PRINT01.