The net bytes (i.e. longest record you can write to that track) varies by access method as there is overhead (control bytes). TRKCALC is provided to compute the largest record which can fit on a track (using EXCP), see https://www.ibm.com/docs/en/zos/3.2.0?topic=instructions-performing-track-calculations-trkcalc-macro
Unless you are using EXCP the hardware track capacity is irrelevant, the access method used will determine the actual bytes per track (and varies by BLKSIZE). On Tue, Jun 30, 2026 at 10:35 AM Joseph Reichman < [email protected]> wrote: > Would anyone know how to get the net bytes per track for a 3390 > > I have been using devtype ddname,buffer,devtab > > > Where buffer is a 32 byte output field > > But it keeps on coming back with the overhead of 58,864 > > I think the net is 56,664 > > I would like to get that figure programmatically instead of hard coding it > > Thanks > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to [email protected] with the message: INFO IBM-MAIN > ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
