Introduction MTB Statements File System Compiler Applications Reference Guide Index

Dynamic Driver Libraries

Comet 504 and higher includes a very convenient programming tool: Dynamic Driver Libraries (DDL). This feature provides a way for Comet developers to include custom mnemonics in their programs, and also provides the means for developing custom "drivers" for printers and other devices. This feature makes the MTB language extensible.

Here are the basic specifications for Dynamic Driver Libraries:

  1. Comet developers can define a library of custom mnemonics. Each mnemonic name may be up to 64 characters long.

    For example: (SINGLEKEYTRANSMIT)

  2. When the driver library is processed, all imbedded blanks are removed from the mnemonic names and all characters in the mnemonic names are converted to upper case. This means that you can code the mnemonic names in a more "readable" format.

    For example: (Single Key Transmit)

  3. Each mnemonic may include up to 32 arguments. The arguments may be string constants or variables or numeric constants or variables.

    For example: (Change Colors="07","20","00","00","30")

    You can also skip one or more arguments by including the appropriate commas:

    For example: (Change Colors="07","20",,,)

  4. Signature Systems will maintain a "master list" of developer- defined mnemonics. This list will include the following items:

    This master list will be distributed in a file named MTB50. Comet developers can request a mnemonic name via the "MTB Mnemonic Registration Form."

  5. The actual definition of the mnemonics is done via a new mechanism called a "driver mnemonic library." Several driver mnemonic libraries have been developed by Signature Systems. These libraries are device independent and configurable. Thus, Comet developers will be able to create mnemonic driver tables for various brands and models of printers, or create mnemonic driver tables for other I/O devices. These tables are created via a new Comet utility named MNEMGEN.

Please refer to the following sections: