The PostScript driver can support printers that are not listed in its default list
of the supported printers. Such “external” printers must have accompanying
Windows printer description (WPD) files that provide the information the
PostScript driver needs to access the printer correctly. Typically, printer
vendors create the WPD files for and distribute them with their printers.
In Windows 3.1, the PostScript driver uses the same process to install both internal and external printers. If a printer vendor supplies a WPD file and an OEMSETUP.INF file for the external printer, the user can use the Printers dia- log box in Control Panel to install the printer. In this case, the OEMSETUP.INF file must have a statement having the same form as the following example:
1:PSCRIPT.DRV,1:NEWPRN.WPD,"New PostScript printer","DEVICESPECIFIC"
In this example, 1 represents a logical disk and is previously defined in a [Disks] section. Control Panel automatically installs both the PostScript driver (if necessary) and the WPD file to the SYSTEM directory. The first time the printer is used to print a document, the driver scans all the installed WPD files, and adds the new external printer to the list of installed external printers.
In Windows 3.1, the maximum number of external printers a user can install
depends on the available space in WIN.INI. The theoretical limit is 32,000
printers.