Print Jobs Sent to SFM Printer Hang in Spooler After Printing

Print jobs sent to Services for Macintosh (SFM) AppleTalk-attached printers may be held in the queue for up to ten minutes after they have printed out before the job is deleted and the next job can be printed. After printing, Print Manager displays the job with a size of zero bytes.

When the Services for Macintosh (SFM) print monitor finishes sending data to a printer, it follows with a printer access protocol (PAP) message with the end of file (eof) flag set. Most printers will respond with a PAP eof, but some Apple LaserWriters (e.g. Apple LW 16/xxx) will respond to a PAP EOF with an AppleTalk Transaction Protocol (ATP) release.

This causes the SFM print monitor to wait for the timer to expire. The timer was hard-coded to 10 minutes in 3.51. Thus the print queues were waiting 10 minutes between print jobs.

The timer value has been changed to 30 seconds in Windows NT Service Pack 4, which should help in most instances.

For information on obtaining the Service Pack, query on the following word in the Microsoft Knowledge Base (without the spaces):

PAP eof is passed within an ATP request from machine to machine. The AppleTalk stack then passes the PAP packet on to the SFM Print Monitor. Since some printers do not respond with a PAP eof, but instead an ATP release, the AppleTalk stack processes the packet as an ATP request. Since the packet does not contain additional PAP information the request does not get passed up to the higher protocol.

For additional information on AppleTalk printing, please see the following Microsoft Knowledge Base article: