The IECTRKAD callable service or the TRKADDR macro can be used to perform the following operations on both 16-bit and 28-bit cylinder addresses:

• Calculate the relative track number on the volume
• Compare two track addresses
• Extract the 28-bit cylinder number
• Extract the 4-bit track number
• Increment the track address by one track and increment the cylinder number if necessary.
• Normalize cylinder number to permit comparing one cchh against another
• Convert a relative track number to a 28-bit cylinder address
• Set the cylinder number in a 28-bit track address
• Convert a normalized track address into an absolute 28-bit track address.

See Call for converting and comparing 28-bit cylinder addresses (IECTRKAD) and Perform calculations and conversions with 28-bit cylinder addresses (TRKADDR macro) for more information.