Field boundaries

Assembler language statements usually occupy one 80-character record, or line. For information about statements that occupy more than 80 characters, see Continuation lines. Each line is divided into three main fields:

If it can be printed, any character coded into any column of a line, or otherwise entered as a position in a source statement, is reproduced in the listing printed by the assembler. Whether it can be printed or not depends on the printer.

Uppercase Printing: Use the FOLD assembler option to instruct the assembler to convert lowercase alphabetic characters to uppercase alphabetic characters before they are printed.

Statement field

The instructions and comment statements must be written in the statement field. The statement field starts in the begin column and ends in the end column. The continuation-indicator field always lies in the column after the end column, unless the end column is column 80, in which case no continuation is possible. The identification-sequence field usually lies in the field after the continuation-indicator field. Any continuation lines needed must start in the continue column and end in the end column.

Blank lines are acceptable. For more information, see Blank lines.

The assembler assumes the following standard values for these columns:

These standard values can be changed by using the Input Format Control (ICTL) assembler instruction. The ICTL instruction can, for example, be used to reverse the order of the statement field and the identification-sequence field by changing the standard begin, end, and continue columns. However, all references to the begin, end, and continue columns in this manual refer to the standard values described above.

Continuation-indicator field

The continuation-indicator field occupies the column after the end column. Therefore, the standard position for this field is column 72. A non-space character in this column indicates that the current statement is continued on the next line. This column must be a space character on the last (or only) line of a statement. If this column is not a space, the assembler treats the statement that follows on the next line as a continuation line of the current statement.

If the DBCS assembler option is specified, then:

Identification-sequence field

The identification-sequence field can contain identification characters or sequence numbers or both. If the ISEQ instruction has been specified to check this field, the assembler verifies whether or not the source statements are in the correct sequence.

The columns checked by the ISEQ function are not restricted to columns 73 through 80, or by the boundaries determined by any ICTL instruction. The columns specified in the ISEQ instruction can be anywhere on the input statement, including columns that are occupied by the statement field.


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