Format-F and format-U records are acceptable to both the reader and the punch. Format-V records are acceptable to the punch only. The device control character, if specified in the RECFM parameter, is used to select the stacker; it is not punched. For control character information, see Using Optional Control Characters. The first 4 bytes (record descriptor word or segment descriptor word) of format-V records or record segments are not punched. For format-V records, at least 1 byte of data must follow the record or segment descriptor word or the carriage control character.
A record size of 80 bytes is called EBCDIC mode (E) and a record size of 160 bytes is called column binary mode (C). Each punched card corresponds to one physical record. Therefore, you should restrict the maximum record size to EBCDIC mode (80 bytes) or column binary mode (160 bytes). When column binary mode is used for the card punch, BLKSIZE must be 160 unless you are using PUT. Then you can specify BLKSIZE as 160 or a multiple of 160, and the system handles this as described under PUT—Write a Record. Specify the read/punch mode of operation (MODE) parameter as either card image column binary mode (C) or EBCDIC mode (E). If this information is omitted, E is assumed. The stacker selection parameter (STACK) can be specified as either 1 or 2 to show which bin is to receive the card. If STACK is not specified, 1 is assumed.
For all QSAM RECFM=FB card punch data sets, the block size in the DCB is adjusted by the system to equal the logical record length. This data set is treated as RECFM=F. If the system builds the buffers for this data set, the buffer length is determined by the BUFL parameter. If the BUFL parameter was not specified, the adjusted block size is used for the buffer length.
If the DCB is to be reused 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 expected. You can ensure the buffer size by specifying the BUFL parameter before the first time the data set is opened, or by issuing the FREEPOOL macro after each CLOSE macro so the system will build a new buffer pool of the correct size each time the data set is opened.
Punch error correction on the IBM 2540 Card Read Punch is not performed.
The IBM 3525 Card Punch accepts only format-F records for print and associated data sets. Other record formats are permitted for the read data set, punch data set, and interpret punch data set.