xcall DSKCOM, opcode, msgnam, var
DSKCOM is identical to COMMON except that it is disk-based, allowing sharing of information between different jobs. Also, the package name (msgnam) may be up to twelve characters instead of the standard six. This allows you plenty of space to prepend the jobname if you want to identify which packets go with which jobs.
The file is opr:common.sys, and will be automatically created on first access if it does not exist. You can erase it to forcefully reset any existing packets.
The number and size of packets is determined in the same way as for COMMON, i.e. via the SBR=MSGNUM:#,MSGSIZ:# system parameters. The default is six packets of 150 bytes.
You may use ALIAS=COMMON:DSKCOM if you want to convert your existing COMMON to disk based.
