<snip> First of my Assembler code is RMODE31 So I anyway have to call something below the line to open to read to close </snip>
It is not true that you have to call something below the line. Code doing OPEN and CLOSE can be RMODE 31, quite possibly needing to specify MODE=31. The DCB itself needs to be below 16M. Even exits via the DCBE can be above 16M. Peter Relson z/OS Core Technology Design
