The CSCB is comprised of a 36-byte block which is always obtained below 16 megabytes and a 256-byte block whose residence is governed by this parameter. Be careful when specifying CSCBLOC=BELOW to not over-specify the MAXUSER or RSVSTRT values by too great an amount as they are used to determine the number of CSCBs allocated. At a minimum, over 9000 bytes are allocated below the line and additionally over 64000 bytes are allocated based on the CSCBLOC setting. Using large values for MAXUSER or RSVSTRT reduces the amount of CSA storage below 16MB available for other applications. This might result in an ABEND878 when applications are started after IPL or cause a wait state 040 to occur at IPL time. For example, if you specify a combined MAXUSER and RSVSTRT value of 5000, over 22500 bytes are initially allocated below 16 megabytes and additionally over 160000 bytes are initially allocated based on the CSCBLOC setting.
Value Range: Not applicable
Default Value: CSCBLOC=ABOVE
Associated Parmlib Member: None