Comet98 Printer Configuration Guidelines

Here are some basic guidelines to follow when configuring printers under Comet98. We have included configuration steps, a discussion of the advantages and disadvantages of different configuration modes, and an introduction to the Driver Event Server feature available in Comet98.

Configuration Steps

1. Configure and test your printer using the standard Windows "Add Printer" function found in the "Printers" folder located in the "Settings" menu off of your Windows "Start" menu. This printer should be able to perform all of its advertised functions when used from a Windows program such as a word processor, spreadsheet, or graphics application.

2. Add an entry to the "[Printers]" section of your Comet configuration .INI file as follows:

   Printer = Comet printer,W,Spool Type,Spool Name,Windows printer,DES program,;
   

   where:

   Comet printer is any valid Comet printer name (e.g., LP1, LP2, LPW)

   Spool Type is N (none), E (exception), or A (auto)

   Spool Name is the name of a Comet spool (e.g., SP1, SP2)

   Windows printer is the name of the Windows printer set up in step 1 (as it appears in the folder). For "raw" mode of operation, the control word ":RAW" is appended to the name. See below for more information.

   DES program is the name of a Driver Event Server program (if any) that this printer will use. See below for more information.

   Examples:

   Printer = LP1, W, N, , Epson MX80:RAW,,;        ; Raw mode
   Printer = LP2, W, N, , Epson MX80,,;		; Cooked mode
   Printer = LP3, W, A, SP1, HP LaserJet 4,, ;     ; Cooked mode
   

3. Load Comet (if not already running) and run the SYSGEN utility program. Choose option 1 to generate a new Comet .CFG file. Restart Comet and test your application. It should print as it did under the 504 DOS version of Comet.

"Raw" vs. "Cooked" Mode Printers

The primary difference between a "raw" mode printer and a "cooked" mode printer is the addition of the control word ":RAW" to the Windows printer name for a raw mode printer. A raw mode printer is required for fully 100 percent Comet/DOS compatible printer operation.

The features for each print mode are as follows:

Raw Mode:

• Advantages:
  • Provides 100% compatibility with existing MTB applications.

  • The application may use printer-specific control codes to modify the printer's behavior.

• Disadvantages:
  • Requires direct knowledge of specific printer codes by MTB applications to perform special operations (compressed print, etc.).

  • The application may not use any Windows-oriented printer controls such as font selection, line drawing etc.

Cooked Mode:

• Advantages:
  • Provides an MTB application with access to the Windows Graphical Device Interface (GDI), providing enhanced features allowing custom forms to be printed directly under MTB program control.

  • Provides limited compatibility for those legacy applications that use standard sized printer forms. Different sized forms may be used if the printer itself has knowledge of the form size when performing a form-feed (note that this is usually NOT the case).

  • Printer font type/size may be modified by specifying Windows fonts.

  • Knowledge of the specific kind of printer or its control codes is not required by the MTB application to use enhanced features.

• Disadvantage:
  • Legacy programs that rely on line counting to print non-standard sized forms may not function properly.

Discussion

[Printer Fonts]
printer name Font-n = font, height, chars per inch, weight

where:

printer name is the name of a Windows printer. If omitted, this entry represents the default for all printers not listed.

n is a number to represent the font. The current standard for font usage is:

  0 represents a normal size font
  1 represents a compressed or narrow font
  2 represents a expanded or wide font

font is the name of an existing Windows font

height is the character height specified in points

chars per inch is the desired number of chars per inch

weight is the heaviness of the font (range=0-1000, normal=400)

Examples:

; for printers not listed separately
Font-0 = Courier New, 12, 10, 400
Font-1 = Courier New, 12, 17, 400
Font-2 = Courier New, 12, 6, 400

; for HP LaserJet 4 only
HP LaserJet 4 Font-0 = Courier, 12, 10, 400

1. Configure the Windows printer using the supplied "Generic" printer driver available when setting up your printer. Because generic printers are "text only" printers, Windows will not attempt to load any fonts to the printer, resulting in the printer using whatever font (or other settings) set by the factory or the front panel.

2. Use the raw mode described earlier in this document.

Driver Event Servers (DES)

A Driver Event Server (DES) is nothing more than an MTB subprogram that is "entered" transparently to the user program. Once in control, the DES program can access the printer and perform various operations to prepare a page for printing by the user application.

As is implied by its name, a DES is entered only in response to certain printer events. Currently those events supported are: Initialization (just after the printer has been opened), NewPage (before a form feed), and Shutdown (just before the printer is closed).

The following example shows how a DES can be included in your Comet .INI configuration file:

  Printer = LPW, W, N, , HP LaserJet 4, PWMARK,;

1. PWMARK (source #PWMARK) draws a water mark on each page
2. PFORM (source #PFORM) generates a sample invoice form
3. PFONT N/C/E (source #PTRFNT)

   Each selects one of the system fonts as follows:
   N = System font 0 (normal print)
   C = System font 1 (compressed [narrow] print)
   E = System font 2 (expanded [wide] print)
   

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