The printer can accept format-F, format-V, and format-U records. The system does not print the first 4 bytes (record descriptor word or segment descriptor word) of format-V records or record segments. For format-V records, at least 1 byte of data must follow the record or segment descriptor word or the carriage control character. The system does not print the carriage control character, if you specify it in the RECFM parameter. The system does not position the printer to channel 1 for the first record unless you use a carriage control character to specify this position.

Because each line of print corresponds to one record, the record length should not exceed the length of one line on the printer. For variable-length spanned records, each line corresponds to one record segment; block size should not exceed the length of one line on the printer.

If you do not specify carriage control characters, you can specify printer spacing (PRTSP) as 0, 1, 2, or 3. If you do not specify PRTSP, the system assumes 1.

For all QSAM RECFM=FB printer data sets, the system adjusts the block size in the DCB to equal the logical record length. The system treats this data set as RECFM=F. If the system builds the buffers for this data set, the BUFL parameter determines the buffer length. If you do not specify the BUFL parameter, the system uses the adjusted block size for the buffer length.

To reuse the DCB with a block size larger than the logical record length, you must reset DCBBLKSI in the DCB and ensure that the buffers are large enough to contain the largest block size. To ensure the buffer size, specify the BUFL parameter before the first open of the data set. Or you can issue the FREEPOOL macro after each CLOSE macro, so that the system builds a new buffer pool of the correct size each time it opens the data set.