SPZAP: Modify data in programs and VTOCs

SPZAP is a service aid program that operates in problem state. SPZAP allows you to dynamically update and maintain programs and data sets. SPZAP can be used to apply fixes to modules or programs that need to be at current levels of the operating system. The functions of SPZAP provide many capabilities, including:
  • Using the inspect and modify functions of SPZAP, you can fix programming errors that require only the replacement of instructions in a load module member of a PDS or a program object member of a PDSE without recompiling the program.
  • Using the modify function of SPZAP, you can set traps in a program by inserting incorrect instructions. The incorrect instructions will force abnormal ending; the dump of storage provided as a result of the abnormal ending is a valuable diagnostic tool, because it shows the contents of storage at a predictable point during processing.
  • Using SPZAP to replace data directly on a direct access device, you can reconstruct VTOCs or data records that may have been destroyed as the result of an I/O error or a programming error.
  • On the advice of the IBM® Support Center, start tracing in system components that do not use component trace. The IBM Support Center will tell you how to use the SPZAP service aid to start traces in these components.
  • Update the system status index (SSI) in the directory entry for any load module in a PDS or program object in a PDSE. Update the CSECT identification record (IDR) in any load module in a PDS or program object in a PDSE.