Xerox 721P85530 用户手册
SPECIFYING INPUT PARAMETERS
XEROX DOCUPRINT 180 LPS PDL REFERENCE
4-7
ZERO
This parameter specifies the end of block indicator.
Syntax
BLOCK ZERO =
option(s)
Options
Table 4-12 lists the parameter option(s) and definition(s).
Points to note
Note the following when using the BLOCK command:
•
The LENGTH parameter may be overridden by ANSI, IBM OS/
Standard, or Honeywell 2000 COBOL labels that specify block
length.
Standard, or Honeywell 2000 COBOL labels that specify block
length.
•
The values for LTHFLD, OFFSET, FORMAT, and PREAMBLE
may be overridden if RECORD STRUCTURE is changed as the
result of ANSI, IBM OS/Standard, or Honeywell 2000 COBOL
label processing.
may be overridden if RECORD STRUCTURE is changed as the
result of ANSI, IBM OS/Standard, or Honeywell 2000 COBOL
label processing.
•
The length on a 4-by-3 packed format tape or Honeywell 600 is
the number of 6-bit bytes or characters in the tape block.
the number of 6-bit bytes or characters in the tape block.
•
The length of the block delimiter constant should not be coded
as the BLOCK POSTAMBLE. Both lengths are subtracted from
the end of the block.
as the BLOCK POSTAMBLE. Both lengths are subtracted from
the end of the block.
•
The search for the block delimiter constant starts after the block
preamble and proceeds forward to the first appearance of the
constant.
preamble and proceeds forward to the first appearance of the
constant.
•
The maximum block size that may be processed by the input
task is 24,576 bytes. The input task is able to allocate at least
one input buffer for offline tape jobs when the tapes are written
in maximum size blocks.
task is 24,576 bytes. The input task is able to allocate at least
one input buffer for offline tape jobs when the tapes are written
in maximum size blocks.
•
If a block length is specified which is less than this minimum
block length found on the tape, input processing allocates input
buffers, which are sized to the minimum tape block length. It is
wise to specify the maximum block length in the JSL, so that
input buffers are large enough to handle the largest block.
However, this may slow performance. If the actual tape block
length is smaller than the JSL block length, then no error
message is reported; otherwise, an error is displayed.
block length found on the tape, input processing allocates input
buffers, which are sized to the minimum tape block length. It is
wise to specify the maximum block length in the JSL, so that
input buffers are large enough to handle the largest block.
However, this may slow performance. If the actual tape block
length is smaller than the JSL block length, then no error
message is reported; otherwise, an error is displayed.
•
If a block delimiter constant is positioned and is part of a record
or block, the user should use caution, since the record or block
or block, the user should use caution, since the record or block
Table 4-12.
ZERO parameter option(s) and definition(s)
Option(s)
Definition(s)
YES
Specifies that the end of a tape block is indicated by
a value of 0 in the record length field (before applying
the record length adjustment). Data that follows the
record is ignored up through the end of the block.
a value of 0 in the record length field (before applying
the record length adjustment). Data that follows the
record is ignored up through the end of the block.
NO
Indicates that the end of a tape block is not indicated
by a value of 0 in the record length field.
by a value of 0 in the record length field.
The default is NO.