360 Assembly/Pseudo Instructions

From Wikibooks, open books for an open world
Jump to: navigation, search

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.

  • AGO - Conditional transfer of assembly
  • AIF - Conditional test at assembly time
  • ANOP - Assembly time NO-OP
  • COPY - Include the contents of another source file at this point
  • CCW - Create a Channel Command Word for Input/Output instructions
  • CNOP - Address conditional NO-OP
  • DC - Define a constant value
  • DS - Declare a storage area
  • CSECT - Declare start of a module
  • DROP - Declare register address contents no longer valid
  • DSECT - Declare start of a virtual module
  • EJECT - Eject page on listing
  • EXTRN - Define external module
  • END - End of source with optional start point
  • EQU - Equate a symbol to a value
  • GBLA / GBLB / GBLC - Declare global symbols
  • ICTL - Set source code margins
  • LCLA / LCLB / LCLC - Declare local symbols
  • LTORG - Force all immediate constants to be declared at this point
  • PRINT - Change printing options for the listing or start or stop listing
  • MACRO - Start a macro
  • MEND - End a macro
  • MEXIT - Exit a macro
  • MNOTE - Issue a message, warning or error in a macro
  • ORG - Indicate the current address
  • POP - Restore the previous PRINT option state
  • PRINT - Change the current printing options
  • PUSH - Save the current PRINT option state
  • SETA / SETB / SETC - Conditional assignment
  • SPACE - Insert one or more blank lines in the printout
  • START - Declare start of a module
  • TITLE - Set name to show on listing
  • USING - Declare address contents of a register
  • WXTRN - Define weak reference to external module
360 Assembly Language
360 Family Introduction · Basic FAQ · 360 Family · 360 Architecture · Comments
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
Instruction Extensions Floating Point · High-Level Languages