The RECL=rl clause is required if ACCESS='DIRECT' and ignored otherwise.
rl is an integer expression for the length in characters of each record of a file. rl must be positive.
If the record length is unknown, you can use RECL=1; see "Direct Access I/O" for more information.
If -xl[d] is not set, rl is number of characters, and record length is rl.
If -xl[d] is set, rl is number of words, and record length is rl*4. @
There are more details in the ACCESS='SEQUENTIAL' section, above.
Each WRITE defines one record and each READ reads one record (unread characters are flushed).
The default buffer size for tape is 64K characters. For tapes, we recommend the TOPEN() routines because they are more reliable.