The new patch procedure has been added so that any internal APRSa4 routine can be changed via the patch mechanism. The adding of patch files is easy. Simply copy the patch file to the APRSa4 directory. At program startup, APRSa4 will look for patch files. If found, the program code contained in the patch will be loaded and used. The only time patch files are applied is at program startup. Simple fixes can then be downloaded in a short amount of time. All patch files will begin with a P and a 4 digit version number. A patch file for v0.6.13 will start with P0613. Other characters may appear in the patch file name. Multiple patch files may be applied at once. This facility is for development and debug purposes.