To read or write one or more DSCBs by specifying the DSCB's location (that is, BFLEARG), specify either ACCESS=READ or ACCESS=WRITE.

Specify the address of the data set name in the DSN keyword and the address of the buffer list in the BUFLIST keyword. Each of these areas and the associated buffers must be in your program's protect key.

The buffer list must have at least one buffer list entry with the skip bit off and a pointer to a 96-byte or 140-byte buffer. You can chain buffer lists together, but at this time CVAF uses only the first buffer list.

If the first buffer is for a 140-byte read or write, CVAF issues a channel program to read or write the DSCB at the location specified in the buffer list entry. CVAF ignores the specified data set name. If you specify VERIFY=YES, CVAF verifies that the designated DSCB is a format-0 DSCB before issuing the write channel program.

For CVAF calls that specify the DSCB location, a CVAFDIR request will fail if the EADSCB=OK indicator is not set and the DSCB associated with this location is a format-8 DSCB. CVAF return code of 4 with a CVAF status code (CVSTAT) of STAT082 will be set.

If you use CVAFDIR MULTIPLEDSCBS=YES ACCESS=READ, all DSCBs associated with the data set whose format-1 or format-8 DSCB is pointed to by the BFLEARG of the first BFLE entry are read and returned in the buffer list buffer (BFLEBUF) for entries without the skip bit on in logical VTOC order. The associated address of each DSCB is put in the corresponding BFLEARG field. The total number of DSCBs associated with this data set is also returned in the BFLHNOEN field of the buffer list header. If there are not enough buffers to house all the DSCBs associated with this data set name, only those DSCBs that have BFLEs are processed. The buffer list header field BFLHNOEN will then have a number greater than the BFLHNOE field.

If you use CVAFDIR MULTIPLEDSCBS=YES ACCESS=WRITE, all BFLEs without the skip bit are used to write all DSCBs with one call. BFLARG must be correct for all entries and BFLEBUF must point to the correct corresponding DSCB to be written.