CMS data base

    From the version cms100 on CMSIM uses unix directory/file based data base system. The data base files are kept in the public directory $CMS_DB which has several subdirectories, one for each sub-package cmsi, detc, trak etc... The data base files are accessed by a special package called iodb.   The iodb code resides in util/iodb directory.

There are utility routines for opening and closing the files, defining the units etc. The unit numbers are defined implicitly so that the user need not worry about them. All the standard data files needed in cms simulation are given as default dealt in Fortran so that normally no system code (like link or assign) is needed in the job.

Instead of default files the user can define his own i/o files by using the FFREAD control cards CDIR and/or CFIL.     These cards (see section 1.5 are interpreted by the iodb package. The data base system is described in more detail in the reference manual section ii.10.3.