Table of Contents

Exit (EXT)/OP=32

Format

OP A

OP = 32

A is the return address. The address may be indexed, indirect or extended. When not extended, the final address controller bits specify the most significant digit of the address. This permits branching to any address up to and including 299,998, relative to Base #1, without indexing or extension. When the address is indexed, the final Base Indicant should resolve to a value of 1. The processor will always treat the resolved address as being relative to Base #1. The processor will not check for improper memory assignments. The normal return address is obtained by setting the A address to zero, indexing by IX3 and settting the address controller to indirect. When the address is indexed by IX3, the initial contents of IX3 are used.

Function

The Exit instruction reverses the actions of the Enter instruction, thus accomplishing an exit from the stack.

The instruction restores the settings of the Overflow and Comparison flags as specified by IX3 plus 15 if the digit at IX3 plus 14 is zero. if the digit at IX3 plus 14 contains a one, the flags will not be restored. All other values are reserved.

Copy the least significant six digits contained in IX3 to memory location 000040 relative to Base #0.

Copy the eight digits at the location specified by IX3 plus 6 to IX3.

Comparison Flags

If the digit at IX3 plus 14 is zero, set the Comparison Flags and Overflow Flag to the least significant two bits of the digit at IX3 plus 15. See Enter.

Overlap

There are no overlap restrictions for this instruction.

Examples

Example (1) Exit the stack

OP A Syllable
32 F00000
                    BEFORE         AFTER
       NI           nnnnnn        003034
      IX3         +0001024      +0000010
   000040           001046        001024    Top Of Stack
   001024           003034    Unchanged.
                  +0000010    Unchanged.
                         0    Unchanged.
                         6    Unchanged.
                    203010    Unchanged.
  COMPARISON          nn             LOW
  OVERFLOW            nn              ON