Physical Map

What is a physical map

• The physical map is the assembled, loadable form of a BMS map.
• It holds everything CICS needs to paint the screen: constant text, field positions, field lengths and attribute bytes.
• It is generated by the assembler from the mapset source when DFHMSD specifies TYPE=MAP (or TYPE=&SYSPARM).
• At run time CICS loads it when a program issues SEND MAP naming its mapset.

What the physical map contains

• Constant data: screen titles, captions, instructions and function-key legends - the INITIAL values of unnamed DFHMDF fields.
• One attribute byte per field, carrying protection, intensity, shift and MDT settings.
• The position (line, column) and length of every field on the screen.
• The map name taken from the DFHMDI label, which SEND MAP and RECEIVE MAP refer to.

How a physical map is created and used

• Code the mapset with DFHMSD, DFHMDI and DFHMDF macros, then assemble it with the DFHMAPS cataloged procedure.
• The physical map is stored as a load module in the target load library given by the MAPLIB parameter.
• The mapset name must be defined in the PPT so CICS can find it at run time.
• To change a screen, change the mapset source and reassemble - the program itself usually does not need to change.
• Example:-
  
  INQSET1 DFHMSD TYPE=MAP, X LANG=COBOL, X MODE=INOUT, X TERM=3270-2