Printer Plug and Play IDs

http://www.google.com/search?q=cache:www.nondot.org/sabre/os/S7PlugNPlay/PNP-Parellel-v1.0b.pdf+lptenum+device-id+&hl=en&lr=lang_en

A unique Plug & Play ID will be generated for the device using the following algorithm: The MANUFACTURER & MODEL fields will be concatenated, and then a 4 digit checksum will be generated on the resulting string. After the check sum is computed the string will be truncated to 20 characters if its length exceeds 20 characters. The checksum will then be converted to a 4 character string, and appended to the above truncated string, resulting in a string of 24 characters or less.

A code fragment that illustrates how the checksum & device ID values are generated is listed at the end of this document.

For example, the following device ID string will be generated for the HP LaserJet 4P printer:

"Hewlett-PackardHP_La7EE2"

since the MFG field is Hewlett-Packard, and the MDL field is HP LaserJet 4P.

The parallel port enumerator will then prepend "LPTENUM\" (minus quotes) to the string generated above, and the resulting string will be the Plug and Play ID value. The Plug & Play ID will be used to search all known device information files (INF in Windows) available on the host for a driver which will support the device. Note the ordering of device ID values listed in the INF files will be significant in determining the device driver which is the "best match" for a given device. See the section below on "Ordering Device ID values" for a more detailed description.

http://www.osr.com/ddk/gs_sign_8k4n.htm

http://www.google.com/search?hl=en&lr=lang_en&safe=off&q=lptenum+device-id+&btnG=Google+Search

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