General Information About Print Manager and Windows 3.1

• Microsoft Windows operating system versions 3.1, 3.11

SUMMARY

This article contains information about printing from the Microsoft Windows version 3.1 with Print Manager. This article provides an overview of the flow of data through Windows during printing and instructions for using the Print Manager, the Fast Printing Direct to Port option, and the Print Network Jobs Directly option.

MORE INFORMATION

Print Manager Disabled

The simplest printing setup in Windows 3.1 is with the Print Manager disabled. In this situation, only one application can print at a time. Print Manager is not running, so there is little memory overhead (Print Manager can take up to 50K of memory). Disabling Print Manager should improve performance if you frequently run out of memory. Printing without the Print Manager also requires less disk space for temporary files.

The general order of printing is as follows:

1. The application makes a Windows function call to create the output.

2. Windows translates those calls into printer driver function calls.

3. The device driver converts the drawing function calls into printer specific draw commands. In the case of dot-matrix printers and non-PostScript laser printers, a bitmap containing the graphics is generated.

4. GDI.EXE outputs the printer commands to the port or network server.

Print Manager Enabled

With Print Manager enabled, the conditions are similar; however, there are a few significant differences.

1. Instead of writing the printer commands (the output of the printer driver) to the port or network spooler, GDI writes the output to temporary files. The temporary files are sent to the port by Print Manager.

2. Print Manager does not try to write the files to the port until the application and the driver have finished producing all the files needed to print the entire job. (This is called "spooling.")

3. Print Manager allows more than one application to spool and therefore print at one time. This is possible because several applications can create temporary files (that is, "spool") simultaneously. Print Manager then prints them in order.

4. Print Manager provides informative error messages when things go unexpectedly.

The negative effect of spooling is that disk space is required for each spooled file.(These files are stored in the temporary directory.) Therefore, you may run out of disk space while printing. If this problem occurs, spooling stops temporarily and Print Manager attempts to free disk space by writing the first few pages of the document to the printer. The application is suspended until enough disk space has been freed to allow spooling to finish.

Windows 3.0 handles printing differently than Windows 3.1; Windows 3.0 tries to both spool files and print them at the same time. The result is that the application is suspended for a longer period of time. The Windows 3.1 approach takes exactly the same time to print the document as Windows 3.0, but the application allows you to continue working on other tasks sooner.

Sending Printer Commands to Ports

Whether Print Manager is enabled or disabled, Windows has several methods for sending printer commands to a printer port. GDI or Print Manager determines how to print the file by examining the configuration of the port. If the port is connected to a network printer, the network driver creates a print job on the network spooler. GDI or Print Manager then uses MS-DOS to write data to the network spooler.

If the port is recognized by the Windows COMM (communications) driver and the Fast Printing Direct To Port option is turned on, GDI or Print Manager uses the COMM driver to send the printer data to the printer. The COMM driver supports COM and LPT ports whose addresses are found in the ROM BIOS data area (the eight words starting at 40:0).

If the port is not accepted by the network driver or the COMM driver (for example, when printing to a file or to a character device driver that is not a COM or LPT port), GDI and Print Manager uses MS-DOS to open and write functions to output the print data.

Fast Printing Direct to Port

Enabling this option (accessed by choosing "Printer Setup" and then "Connections") causes Windows to print using the Windows COMM driver whenever appropriate. The COMM driver supports faster printing than MS- DOS by writing directly to the COM or LPT port hardware but bypassing the normal MS-DOS output code path. If special print terminate-and- stay-resident programs (TSRs) are being used or you are experiencing problems printing over a network, disabling this option may correct these problems.

Note: This is exactly the same as printing to LPT1.OS2 in Windows 3.0, but this setting is for ALL ports. This option is active by default.

Print Network Files Direct

Enabling this option under Network Settings stops Print Manager from spooling network jobs on the local hard drive and allows local jobs to be spooled as normal. If the server supports spooling of print jobs (almost all do) then enabling this option saves disk space when printing to a network printer without affecting the print speed or the time the application is suspended. This option is active by default.

Disable this option, if any of the following conditions exist:

   It is known that the server doesn't support spooling.
   Printing slows down with this option enabled.
   You get network errors with this enabled.

Handshaking and Error Checking

The Windows COMM driver supports both hardware and software handshaking on serial ports and all standard control signals on parallel ports. When using the COMM driver (printing Direct to Port is active) with a parallel port, Windows also resets the printer between documents. The errors supported by parallel ports are "printer offline," "printer out of paper," "general error," and "printer not ready," which is actually a time-out condition on the printer busy signal. There is no standard for returning printer errors on serial ports; however, "printer not ready" time-outs result if handshaking is used and the printer does not accept data.