Determine the length of the longest possible record that can be written on a track

To determine the length of the longest possible record that can be written on a track, code FUNCTN=TRKBAL, REMOVE=NO, MAXSIZE=YES. You must specify the number of existing records on the track (using either the R keyword or the RKDD parameter) and a data length of X'FFFF' (using either the DD keyword or the RKDD parameter). The DD value of X'FFFF' is greater than is supported on any disk. Expect a return code 8, which means that the record does not fit and TRKCALC returned the size of the largest possible record.

If you wish to regard the track as being empty, specify an R value of 1.

If the track is not empty, specify an R value that is one greater than the number of existing records on the track and code the BALANCE parameter. In this case, TRKCALC will give return code 8 and the length of the longest possible record that will fit on the rest of the track.

Note: The value returned might be larger than what is supported by any access method other than EXCP.