Specifying disk extents
In most disk functions, you can specify a disk address or a disk address range. You can specify these addresses in the form cylhd, where the last 2 digits represent the head value and the other digits represent the cylinder.
If the CYLHD entry field of the Set Processing Options panel has the value ABSOLUTE, each cylhd value represents an absolute address (counting from the beginning of the physical disk). If the entry field has the value RELATIVE, each cylhd value represents an address relative to the beginning of the data set. (See Set System Processing Options panel (option 0.2) for more information.)
The entry panels for the Disk/VSAM Data Functions tell you whether absolute or relative addresses are in effect.