At the beginning of each DADiSP session, the system.mac and dadisp.mac files are read into the Worksheet. The system.mac file is shipped with the product, and contains macros that work in conjunction with DADiSP's menu system to provide standard analytics and application control. You should not edit the macros in the system.mac file. The dadisp.mac file is not shipped with the product, so you can create one, and put whatever macros you want loaded at startup into this file. You can either define your macros in the dadisp.mac file directly, or use the #include function to reference other macro files that you want automatically loaded upon startup.