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360 Assembly/Pseudo Instructions

Pseudo Instructions are special commands to the assembler about the positioning of the program, the address the program should presumed to be assembled at, the name of the module, data declarations, the title and printing options for the program, defining and calling macros, macro looping and test, and end of source code. Unless a machine instruction is issued, these do not generate executable code.

The pseudo instructions varied from version to version of the assembler, and higher-level and more powerful assemblers provided for all of the instructions. All pseudo instructions are 2-5 letters in length. The following lists the general pseudo instructions available. Some pseudo instructions are used for conditional assembly or macro processing, and some are only available while processing a macro.

  • *PROCESS - Special processing options
  • ACONTROL - Change assembler options and controls
  • ACTR - Limit AIF/AGO branch counts in macros
  • ADATA - Writes information to the ADATA file
  • AGO - Conditional transfer of assembly
  • AIF - Conditional test at assembly time
  • AINSERT - Insert records into input stream
  • ALIAS - Supply alternate name for external symbol
  • AMODE - Declare addressing mode
  • ANOP - Assembly no-op
  • AREAD - Read from input stream
  • CATTR - Specify a class name and attributes
  • CCW - specify 8-byte, 24-bit address I/O instruction
  • CCW0 - Same as CCW
  • CCW1 - Specify 8-byte, 31-bit address I/O instruction
  • CEJECT - Conditional ejecf
  • CNOP = Conditional no-op
  • COM - Declare common control section
  • COPY - Include code
  • CSECT - Declare a control section
  • CXD - Return total external dummy section size
  • DC - Declare a constant value
  • DROP - Discontinue use of an addressing register
  • DS - Declare name for a storage location
  • DSECT - Declare a dummy section
  • DXD - Define external dummy section
  • EJECT - Skip to next page on listing
  • END - Declare end of an assembly
  • ENTRY - Declare a public entry point
  • EQU - Declare a symbol
  • EXITCTL - Set values to pass to certain user exits
  • EXTRN - Declare a strong (required) external symbol
  • GBLA / GBLB / GBLC - declare a global symbol for a macro
  • ICTL - Declare source code column margins
  • ISEQ - Validate sequence numbers
  • LCLA / LCLB / LCLC - declare a local symbol for a macro
  • LOCTR - Specify multiple location counters
  • LTORG - Generate all literals
  • MACRO - Declare the start of a macro
  • MEND - Declare the end of a macro
  • MEXIT - Declare the termination of processing of a macro
  • MNOTE - Declare error (or warning) in a macro
  • OPSYN - Define or delete an op code
  • ORG - Set current location counter value
  • POP - Restore PRINT settings
  • PRINT - Declare listing conditions
  • PUNCH - Add information to object output
  • PUSH - Save current PRINT settings
  • REPRO - Copy next card to object file without translation
  • RMODE - Declare real addressing mode
  • RSECT - Declare a read=only CSECT
  • SETA / SETB / SETC - declare value of a conditional symbol
  • SPACE - Generate blank lines in listing
  • TITLE - Add a title to a listing
  • START - Declare the start of a control section
  • USING - Declare addressing registers
  • WXTRN - Declare weak (optional) external symbol
  • XATTR - Assign attributes to an external symbol
  • Comments - Programmer remarks about the program
360 Assembly Language
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360 Instruction Set 360 Instructions · Branch Instructions · Data Transfer Instructions · Control Flow Instructions · Arithmetic Instructions · Logic Instructions · Shift and Rotate Instructions · Other Instructions
Syntaxes and Assemblers 360 Assemblers· Pseudo Instructions
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