Printers and Fonts Kit(3.1) (pfk31qh.hlp) (
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External PostScript Printers
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In addition to supporting a wide variety of PostScript printers, the
Microsoft Windows PostScript printer driver can also support any new
PostScript printers for which the user installs an external printer
definition.
For the user to be able to do this, the printer manufacturer must supply a
Windows Printer Description (WPD) file that contains information about the
new printer. Printer manufacturers create the WPD files by compiling
Adobe-standard PostScript Printer Description (PPD) files with the MKPRN
utility. This topic describes how font manufacturers can build the WPD files
and distribution disks that will enable users to add a printer to the
Microsoft Windows PostScript printer driver.
Building and Distributing WPD Files
To build Windows Printer Description files, a font manufacturer must first
build PPD files for each printer and PFM files for the each printer's
resident font or soft fonts. The font manufacturer then uses the MKPRN
utility to generate the WPD file.
To distribute WPD files, a font manufacturer copies the WPD file to disk
along with a OEMSETUP.INF file that describes the external printers the WPD
file supports.
Once a WPD file is installed, it defines the following features of the
external printer:
♦ Resident fonts
♦ Paper sizes and input trays
♦ Commands that activate sizes and trays
♦ Imageable area of each supported page size (that is, the area on which
the printer can actually mark)
The following sections describe the formats of the various files.
PostScript Printer Description Files
The PostScript Printer Description file format, defined by Adobe and
extended by the Microsoft, provides the basis for external printer
descriptions. This ASCII file contains one or more statements, each
consisting of a keyword and associated values.
Each keyword defines a feature of the PostScript printer. The associated
values specify whether the feature is available, or how the feature affects
the operation of the printer. For example, the "*FileSystem" keyword
specifies whether a printer supports fonts loaded on a hard drive. PPD files
must be standard ASCII files with carriage return and line feed pairs
terminating each line.
To ensure the best performance for a printer, the PPD file should be as
complete as possible. Windows 3.1 has defined new PPD keywords that should
be added to existing PPD files to create new WPD files. If these keywords
are not added, the driver can still use the old WPD files, but it will
assign default values to any keywords not explicitly defined.
The following provides descriptions of the PPD keywords.
Keyword Description
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*ColorDevice Indicates whether the printer supports color.
*DefaultFont The name of the default font (that is, the font used
if none is selected). This setting must appear before
any "*Font" settings.
*DefaultInputSlot The default input slot.
*DefaultResolution The default resolution of the printer.
*Duplex PostScript commands to set duplex mode. This feature
is new for Windows 3.1.
*FileSystem Reserved; do not use.
*Font The fonts resident in the printer.
*FreeVM Amount of free memory in standard printer
configuration. This feature is new for Windows 3.1.
*ImageableArea The actual area that can be marked on for every paper
size.
*InputSlot The PostScript code that is necessary to specify each
input slot.
*ManualFeed False The PostScript code that is necessary to turn off
manual feed. If present, it is assumed that manual
feed is supported.
*ManualFeed True The PostScript code that is necessary to specify the
manual feed operation. If present, it is assumed that
manual feed is supported (and therefore PageRegion
settings must be included).
*NickName The name that appears in the printer dialog box. It
should be a unique description of the printer. This is
also the name used for automatic printer recognition.
*PageRegion The PostScript code that is necessary to specify
different page sizes when using manual feed.
*PageSize The PostScript code used to specify the different page
sizes that are supported (when not in manual-feed
mode).
*PaperDimension The size of all the used paper types. A Paper
Dimension setting must be included for every size of
paper supported. The sizes of the standard page types
should be used. Only standard page types are
recognized.
*SetResolution Used to determine the hardware resolution(s)
supported. This feature is new for Windows 3.1.
*Transfer Normalized The normalized transfer function used to generate
linear gray levels. This must be present. If none is
required, include the nul function "{ }."
The following is a list of PPD extensions.
Extension Description
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*AcceptsTrueType: True or false. If true, TrueType fonts will be downloaded
natively using readhexsfnt operator. This is selected
through the download option in the Advanced Options
dialog box. If false, TrueType will not be displayed as a
selection. This feature is new for Windows 3.1.
*EndOfFile Indicates whether ^D is required to indicate the end of
the file. This is true by default, and only needs to be
included if this is false (that is, "*EndOfFile False").
*SetPage True or false. If true, the PostScript driver allows a
custom paper size to be defined. This is implemented
through the use of the setpage operator. If your printer
supports the setpage operator in the same manner as
Linotronic(R) printers, you can use this option.
*TrueImageDevice: True or false. If true, the PostScript driver takes
advantage of some optimizations available in TrueImage.
Currently there is very little difference in the output.
This feature is new for Windows 3.1.
The following are the paper keywords used to show the paper sizes
supported.
Keyword Description
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10x14 10 x 14 inches physical size, oriented in portrait mode.
11x17 11 x 17 inches physical size, oriented in portrait mode. Can
be used interchangeably with the keyword "Tabloid."
A3 297 x 420 millimeters physical size, oriented in portrait
mode. Refers to the International Standards Organization
(ISO)/(JIS) A3 paper size.
A4 210 x 297 millimeters physical size, oriented in portrait
mode.
A4Extra 9.27 x 12.69 inches physical size.
A4Small 210 x 297 millimeters physical size, but with a reduced-size
imageable area of 7.47 x 10.85 inches that is centered on an
A4 page. Supports the Adobe PostScript paper definitions.
A5 148 x 210 millimeters physical size, oriented in portrait
mode.
B4 250 x 354 millimeters physical size, oriented in portrait
mode. Refers to the Japanese Industrial Standard (JIS) B4
paper size.
B5 182 x 257 millimeters physical size, oriented in portrait
mode.
Folio 8.5 x 13 inches physical size, but with a reduced-size
imageable region, oriented in portrait mode and centered on
the folio sheet. Supports the Adobe PostScript paper
definitions.
Ledger 17 x 11 inches physical size, oriented in landscape mode (that
is, the y-axis is on the shorter edge of the paper).
Legal 8.5 x 14 inches physical size, oriented in portrait mode.
LegalExtra 9.5 x 15 inches physical size.
Letter 8.5 x 11 inches physical size. Refers to the standard paper
type.
LetterExtra 9.5 x 12 inches physical size.
LetterSmall 8.5 x 11 inches physical size, but with a reduced-size
imageable region that is centered on the page. Supports the
Adobe PostScript paper definitions.
Note 8.5 x 11 inches physical size, but with a reduced-size
imageable region. This is used to reduce the size of the page
buffer to give print jobs more memory.
Quarto 215 x 275 millimeters physical size, but with a reduced-size
imageable region, oriented in portrait mode and centered on
the quarto sheet.
Statement 5.5 x 8.5 inches physical size, oriented in portrait mode.
Tabloid 11 x 17 inches physical size, oriented in portrait or tabloid
mode (that is, the y-axis is on the longer edge of the
paper).
TabloidExtra 11.69 x 18 inches physical size.
For paper extensions, five standard envelope sizes are recognized. The two
groups of numbers following the word Envelope indicate the size of the
envelope in points (where each point equals 1/72 of an inch).
Extension Description
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Envelope.279.639 #9 Envelope (3.875 x 8.875 inches)
Envelope.297.684 #10 Envelope (4.125 x 9.5 inches)
Envelope.324.747 #11 Envelope (4.5 x 10.375 inches)
Envelope.342.792 #12 Envelope (4.75 x 11 inches)
Envelope.360.828 #14 Envelope (5 x 11.5 inches)
The following are the paper tray and bin keywords used to show and specify
the input slots supported.
Keyword Description
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LargeCapacity This one can hold more than a standard amount of paper.
Lower If there is more than one tray, this one is on the bottom.
Middle This one is in the middle.
OnlyOne There is only one tray.
Upper If there is more than one tray, this one is on top.
The following list describes the paper tray extensions.
Extension Description
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AutoSelect Printer can select automatically which feeder to use. This
is followed by the code (or a nul command if no code is
required) that is used to specify the autofeed mechanism.
Envelope There is an envelope feeder.
EnvelopeManual There is a manual envelope feeder.
None There are no input feeders. This is treated as being the
same as OnlyOne.
The following keywords are required to support duplex printing.
Keyword Definition
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*Duplex DuplexNoTumble: "statusdict begin false settumble true
setduplexmode end"
*Duplex DuplexTumble: "statusdict begin true settumble true setduplexmode
end"
*Duplex None: "statusdict begin false setduplexmode end"
*DefaultDuplex None
If the PPD with correct *Duplex settings is built with the Windows 3.1 MKPRN
utility, the driver expands the Options dialog box to give user control of
duplex settings.
PFM Files for PostScript Printers
Because PostScript fonts are scalable, the PFM files for the PostScript
fonts do not contain width tables. The files have the following form:
PFMHEADER Header; /* font header */
PFMEXTENSION Extensions; /* extensions */
char DeviceName[]; /* printer device name */
char FaceName[]; /* font face name */
EXTTEXTMETRIC ExtTextMetrics; /* extended text metrics */
WORD ExtentTable[]; /* unscaled character widths */
DRIVERINFO DriverInfo; /* driver-specific information */
PAIRKERN KerningPairs[]; /* pair-kerning table (optional)*/
KERNTRACK KerningTracks[]; /* track-kerning table (optional)*/
The PostScript driver for Windows assumes all PostScript fonts are scalable
fonts, so it ignores the dfPoints and dfPixHeight members in the PFM header.
The members dfAvgWidth and dfMaxWidth are in units of 1000 units-per-em.
Although the PostScript naming convention includes the attributes of the
font (that is, bold and italic) in the font name, the attributes should be
stripped from the font name and represented in the dfWeight and dfItalic
members in the PFM header.
The extent table is an array of 16-bit values containing the unscaled widths
of the characters and assuming 1000 units-per-em. The range of the table
should be from dfFirstChar to dfLastChar. The size of the table should be
dfLastChar - dfFirstChar + 1.
Pair-kern values should be in the same 1000 units-per-em measurement as the
extents. As of this writing, we do not know of any application that uses the
track-kern table.
In the EXTTEXTMETRIC structure, the PostScript driver assumes the following
values for each font:
dfVertRes = 300
etmMasterHeight = 300
etmMasterUnits = 1000
In other words, the driver assumes all fonts use Adobe's standard 1000
units-per-em method for describing a font. You must build the extent table
based upon 1000 units-per-em to be consistent with this restriction in the
driver.
The driver also assumes that the font may be scaled to any point size the
application requests. We recommend that the true scaling range of the font
be indicated in the etmMinScale and etmMaxScale members (in device units, at
300 dpi). The driver currently ignores these members.
Because the Windows PostScript driver assumes all PostScript fonts are
scalable fonts, it ignores the etmPointSize member. The etmSize member is
not the point size, but rather the size (that is, the number of bytes) of
the EXTTEXTMETRIC structure.
As of this writing, we do not know of any application that uses the members
in the EXTTEXTMETRIC structure except for etmKernPairs. If your font
contains kern pairs, you must fill in the EXTTEXTMETRIC structure to
indicate the number of kern pairs. Do not leave the other members blank;
fill them in with reasonable values in the event an application does use
them.
The driver-specific data structure pointed to by dfDriverInfo is a
null-terminated string containing the PostScript name for the font. There
are two names for the font:
♦ The Windows name for the font which appears in the font list in the
application's font dialog box.
♦ The PostScript name for the font, which can vary according to printer
manufacturer and which the driver sends to the printer to select the
font.
Both strings must be null-terminated. The Windows name for the font is
pointed to by dfFace and the PostScript name for the font is pointed to by
dfDriverInfo.
To create a PFM file for the internally-supported printers, Microsoft
converts Font Metric (AFM) files to the PFM file format. These files,
provided with the DDK, are ASCII files that define the metrics for each
font. There are 63 AFM files supporting 63 unique fonts. Printers with
resident fonts that are not supported in the current version of the driver
will need to define those files as soft fonts.
If you need to define a font that is not available currently in the
PostScript printer driver, you will need to modify the driver sources to add
additional AFM files. Please refer to the PostScript driver's MAKE file that
is included on the DDK disks for more information on how the driver builds
AFM and PFM files.
Printers Setup File
The printers setup file (OEMSETUP.INF) should reside on the disk distributed
with the WPD file. This file follows the standard format used in the Windows
CONTROL.INF file. It contains a [io.device] section that lists the
PostScript printer names for each set of WPD files included on the disk. The
file has the same form as the following example:
[io.device]
7:pscript.DRV,7:L630_52&.WPD,"Linotronic 630","DEVICESPECIFIC"
If the user tries to install a printer that is already installed, the
printer driver will ask whether the previous WPD file should be updated.
Manufacturers that are already supported internally in the driver should not
provide WPD files with names that conflict with those used internally. If an
update is required, add the PostScript version number to the printer name
(in both the OEMSETUP.INF file and the "*NickName" section of the PPD
file).
Compiling with the MKPRN Utility
The MKPRN utility, an MS-DOS utility, takes a PPD file and all the PFM files
referenced in the PPD file, and produces the WPD file needed for a printer
to be supported by the Windows PostScript printer driver. The utility has
the following command syntax:
mkprn [/v] [/s] ppd-file
Parameter Description
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/v An optional verbose switch. This causes MKPRN to print messages
as it processes various elements in the PPD file. This may be
useful for debugging PPD files.
/s Suppresses combining the PSS, CAP, and DIR files into one WPD
file. This is used only when building the driver sources, and is
not intended for use by external printers.
ppd-file This is the base filename (with no extension) of the PPD file to
be processed. The WPD file shares this base filename.
Error messages are printed for fonts that are not found and for identifiers
that are not recognized. If fonts are not found, they are not built into the
WPD file and have to be added as soft fonts as described in the next
section.
Soft Fonts
A soft font installer is not available yet for the PostScript printer
driver. Therefore, it is up to the printer manufacturer to install
additional fonts as soft fonts by adding the appropriate WIN.INI entries.
The softfontn settings in WIN.INI can be used for several different
purposes. Basically, they inform the driver that a given printer has extra
fonts available and, if necessary, indicate a file that needs to be
downloaded to make that font available. If there is a second file listed in
a softfontn setting, it is assumed that it needs to be downloaded to
activate the given font. Thus, soft fonts can be used to support resident
printer fonts that have been downloaded previously, that reside on a
printer's hard drive, or that are available in some other form.
The softfonts setting indicates how many soft fonts are installed and
listed. The maximum number of soft fonts allowed is based on available
memory and other considerations. The maximum number of soft fonts is at
least 450.
Each softfontn setting references the PFM file associated with a soft font
and, optionally, the soft font that will be downloaded to the printer at
print time. Each filename may be a complete pathname. The two forms of soft
fonts supported are described in the following subsections.
Adobe Soft-Font Format
Adobe soft fonts (files with an .AGB extension) are recognized by the
following string:
%!PS-AdobeFont
The string must be located at offset 6 in the file. The first 6 bytes are
defined by the following data structure:
typedef struct{
unsigned char flag;
char type; /* 1 means data is ASCII, 2 means binary */
/* (convert to ascii) */
long length; /* length of the data that follows */
} HDR;
The members indicate the length of the soft font as well as the type (ASCII
or binary). Binary forms are converted to hexadecimal ASCII by the driver;
ASCII fonts are copied directly.
Non-Adobe Soft-Font Format
Fonts that do not have the above-mentioned signature are copied to the
output stream. Therefore, the whole file must be in PostScript code that
describes the font.
Testing the WPD Files
PostScript printer manufacturers should test their WPD files before
distribution. Do the following:
1 Copy the OEMSETUP.INF and WPD files to a disk.
2 Install the printer by choosing the Add button in the Printers dialog box
in Control Panel. Select the appropriate printer and choose the Install
button.
3 Select the newly installed printer from the Installed Printers list box,
and set it to be the default printer.
4 Test the following features of your printer:
♦ *NickName. Make sure that the model name in the Setup dialog box is
the same as the name in the OEMSETUP.INF file, and the *NickName field
of the PPD.
♦ Paper Sizes. Make sure that all the paper sizes are available and that
the imageable areas are correct.
♦ Paper Sources. Test that all the paper sources can be selected
properly.
♦ Normalized Transfer Function. Use an application (for example,
Micrografx Designer 2.0) that can generate gradiated fills to make
sure that gray levels are represented in a linear fashion.
If you find any problems, make the appropriate changes to the PPD file,
rebuild the WPD file, and install the new WPD over the existing one.
Note: The description string in OEMSETUP.INF needs to match the "*NickName"
keyword from the PPD file.
♦