LU3 Print Sessions Do Not Support Transparent Print Sections (195354)

IMPORTANT: This article contains information about modifying the registry. Before you modify the registry, make sure to back it up and make sure that you understand how to restore the registry if a problem occurs. For information about how to back up, restore, and edit the registry, click the following article number to view the article in the Microsoft Knowledge Base:

256986 Description of the Microsoft Windows Registry

SYMPTOMS

SNA Server's Host Print Server provides a Bypass GDI option for 3270 print sessions that is used to indicate whether the host print data is transparent or not. If this option is selected, all print data received through this 3270 print session will be treated as transparent data, and will be passed directly to the physical printer without modification. The Bypass GDI option has no effect for LU3 print sessions. LU3 print jobs that contain transparent data such as printer control codes (for example, HP PCL commands) or other pre-rendered print data will fail to print, or will print incorrectly even if the Bypass GDI option is enabled.

CAUSE

The Host Print Server was not designed to allow the Bypass GDI option to

function with LU3 print sessions since LU3 print jobs were not intended for

use with transparent print data. IBM originally intended LU3 printing to be used for basic 3270 printing. IBM developed LU1 (SCS) printing to allow for more complex print jobs including transparent print data.

RESOLUTION

SNA Server 3.0

To resolve this problem, obtain the latest service pack for SNA Server version 3.0. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

184307 How to Obtain the Latest SNA Server Version 3.0 Service Pack

SNA Server 4.0

This problem was corrected in the latest SNA Server version 4.0 U.S. Service Pack. For information on obtaining this Service Pack, query on the following word in the Microsoft Knowledge Base (without the spaces):

   S E R V P A C K

MORE INFORMATION

WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.

After applying the update, Bypass GDI is supported for LU3 print sessions if the print session is also configured to use a PDT (Printer Definition Table) file. In addition to applying the update, the following registry entry needs to be added:

Start Registry Editor (Regedt32.exe).
Locate the following key in the registry: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services \SnaPrint\Parameters NOTE: The above registry key is one path; it has been wrapped for readability.

On the Edit menu, click Add Value, and then add the following registry value:

      Value Name: BypassGDIForLU3
      Data Type:  REG_SZ
      Value:      Yes

      NOTE: Value can be set to anything (for example, Yes, On, and so on).
      As long as this parameter exists, the Bypass GDI option will be
      enabled for LU3 print sessions.

Quit Registry Editor.

The following Knowledge Base article discusses an update that is included in SNA Server 3.0 SP3 and SNA Server 4.0 SP1 that allows the Host Print Server to pass EBCDIC X'27' characters for LU3 print sessions.

180150 LU3 Print Job Fails If Data Includes X'27' Control Codes

This capability was added to provide limited transparent section printing for LU3 sessions. The update for this issue required setting a registry parameter called LetHex27Pass to allow EBCDIC X'27' characters to pass through to the printer. However, the update described in this article removes support for the LetHex27Pass registry entry since the print server has been updated to support Bypass GDI for LU3 sessions. Enabling the BypassGDIForLU3 registry entry and applying this update will allow EBCDIC X'27' characters to pass through print server for LU3 sessions.