## Presentation Device Driver Reference for OS/2

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### Hardcopy Driver Migration

Hardcopy drivers must be able to work with earlier levels as well as future levels of drivers across a network. Notice that there are several possible driver version numbers:

EA Version Number. Derived from a build number (such as 13.160)

Dialog Version Number. Derived from the build number. Service representatives can use this number to uniquely identify the build of the hardcopy driver and the fix level.

INI File Data Version Number. Identifies to the driver the version number of the data stored in the OS2SYS.INI file. The numbering system and format is defined by the hardcopy driver.

lVersion Number. Given in the DrivData structure of job or printer properties. The numbering scheme of this ULONG is defined by the hardcopy driver, but the following format of lVersion is suggested. It is a FIXED type of number.

-High WORD. System level in BCD (such as 0020)
-Low WORD. Build level in BCD (such as 0160).

The numbering scheme for drivers is as follows:

New Driver 20.0000
Minor Update 20.0001
Major Release 21.0000

For drivers reading data from an earlier version of the driver, the data must be interpreted (by using the lVersion number as a guide to its format) and any missing data must set to the device defaults. For drivers reading data from a later version of the driver, as much data as possible should be read and the rest ignored. This implies that later versions of the driver only add new driver data fields at the end of the data.