| DSECT Field Name | Field | Control Block Position | Offset | Length (in bytes) | Format |
|---|---|---|---|---|---|
| ABDXLEN | ABD length | 1-2 | 00 | 2 | binary |
| ABDXVER | Version indicator | 3-4 | 02 | 2 | binary |
| ABDXID | Buffer Type ID | 5 | 04 | 1 | alphanumeric |
| ABDXRSV1 | Reserved 1 | 6 | 05 | 1 | binary |
| ABDXLOC | Buffer location flag | 7 | 06 | 1 | alphanumeric/binary |
| ABDXRSV2 | Reserved 2 | 8 | 07 | 1 | binary |
| ABDXRSV3 | Reserved 3 | 9 | 08 | 4 | binary |
| ABDXALET | ALET for buffer (if ABDXLOC=C'D') | 13 | 0C | 4 | binary |
| ABDXSIZE | Buffer size (allocated length) | 17-24 | 10 | 8 | binary |
| ABDXSEND | Data length to send from client to the nucleus | 25-32 | 18 | 8 | binary |
| ABDXRECV | Data length received by the client from the nucleus | 33-40 | 20 | 8 | binary |
| ABDXADRG | 64-bit indirect address pointer (if ABDXLOC=C'I' or C'D') | 41-44 | 28 | 4 | binary |
| ABDXADR | 34-bit indirect address pointer (if ABDXLOC=C'I' or C'D') | 45-48 | 2C | 4 | alphanumeric |
| --- | Buffer (if ABDXLOC=C' ' or X'00') | 49-n | 30 | user-defined | not applicable |
