Multiple LU3 Print Jobs Overwrite Each Other Causing Incorrect Output

An LU3 print job may include data that is sent as part of another LU3 print job. The result is that the LU3 print output includes both incorrect data and incorrect formatting.

The same print jobs print simultaneously when you use SNA Server 4.0.

The print server in Host Integration Server 2000 is designed to release the data buffer that stores the print data when a print job ends. This is not correct behavior for LU3 printing and can cause the problem that is described earlier.

Service pack information

To resolve this problem, obtain the latest service pack for Microsoft Host Integration Server 2000. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

Hotfix information

The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time tool in Control Panel.
Note Because of file dependencies, the most recent fix that contains the preceding files may also contain additional files.

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

This problem was corrected in Microsoft Host Integration Server 2000 Service Pack 2.

This problem occurs if multiple LU3 print jobs are printed simultaneously and if the print jobs do not clear the previous print buffer. A scenario that results in the problem follows:

1. LU3 print job PRINT1 begins with a 3270 Erase/Write (X'F5') command and includes all the correct print data.
2. LU3 print job PRINT2 begins with a 3270 Erase/Write command and includes all the correct print data.
3. LU3 print job PRINT1-A begins with a 3270 Write (X'F1') command and contains 3270 Set Buffer Address (X'11') commands to change some of the print data that was sent in PRINT1.
4. LU3 print job PRINT2-A begins with a 3270 Write (X'F1') command and contains 3270 Set Buffer Address (X'11') commands to change some of the print data that was sent in PRINT2.
5. LU3 print job PRINT1-B begins with a 3270 Write (X'F1') command and contains 3270 Set Buffer Address (X'11') commands to change some of the print data that was sent in PRINT1.
6. LU3 print job PRINT2-B begins with a 3270 Write (X'F1') command and contains 3270 Set Buffer Address (X'11') commands to change some of the print data that was sent in PRINT2.

This sequence may continue and may result in the printing of multiple duplicates of PRINT1 and PRINT2 with only small differences in the PRINT1-x printout and the PRINT2-x printout.

LU3 printing is based on the concept of a screen buffer. The screen buffer is typically 1920 bytes (24 rows by 80 columns) long. If you use the scenario that is described earlier, print job PRINT1 and print job PRINT2 include all the print data for each print job. At this point, the screen buffer for each of these print jobs exists in the memory of the Host Integration Server 2000 Print Server.

The next print jobs contain 3270 Set Buffer Address (SBA) commands that are used to position the cursor at the buffer locations where the data must be changed for the new print output. This method of printing requires that the screen buffer for the initial print jobs is maintained from one print job to the next.

The problem occurs when the Print Server releases the data buffer at the end of each of the unique LU3 print jobs. For example, print data for the PRINT1-B print job ends up being printed on the print session for PRINT2-B.