COMTRAN Reconstruction

J28-6169 · January 1962

02.08.03

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[02.08.03]

D. Machine Language Instructions Generated from CRYPT Language

There are several instances where the System develops instructions which do not agree with those specified by the symbolic source language on a one-to-one basis. If DATE is specified in the Environment and Data Description sections as a field of record to be processed in locate mode, the system will generate for CLA DATE the machine language instructions of the form:

LAC     BASE.LOCATOR.OF.DATE,4
TXL     SYS)294,4,0
CLA     DATE.DISP,4

where:

  • BASE.LOCATOR.OF.DATE contains the current origin of the record in which DATE appears.
  • SYS)294 is an error message routine that prints the fact that BASE.LOCATOR.OF.DATE has not been set if such is the case.
  • DATE.DISP is the displacement of the DATE field from the base location of the record in which it appears.

Note that the contents of index register 4 are destroyed, and that instructions have been inserted in the program. Care must be taken to avoid incorrect referencing when relative addressing using * to signify the location counter is used.

E. Return to Commercial Translator Language

Processing of CRYPT instructions is terminated by an ENTER COMMERCIAL TRANSLATOR instruction. ENTER is punched as an operation code and COMMERCIAL TRANSLATOR as a variable field entry beginning in column 16. The Compiler expects to find Commercial Translator source statements after this instruction.