*DECK MODIN 
USETEXT COMCBEG 
USETEXT COMADEF 
USETEXT COMAFET 
    FUNC MODIN (OFFSET) I;
# TITLE MODIN - MODULO INPUT BUFFER POINTER. #
  
      BEGIN  # MODIN #
  
# 
**    MODIN - MODULO INPUT BUFFER POINTER.
* 
*     MODIN IS A FUNCTION WHICH RETURNS A NEW VALUE FOR THE INPUT FET 
*     OUT POINTER GIVEN AN OFFSET (OR INCREMENT) TO THE CURRENT VALUE.
* 
*     FUNC MODIN (OFFSET) I 
* 
*     ENTRY 
* 
*     EXIT
* 
* 
* 
* 
* 
*     PROCESS    MODIN = FIRST
*                  + MOD((OUT-FIRST + OFFSET), (LIMIT-FIRST)) 
* 
* 
# 
  
  
      ITEM OFFSET  I;                # OUT POINTER INCREMENT #
  
CONTROL EJECT;
  
      IF (GFETOUT + OFFSET) GE GFETLIM
      THEN
        BEGIN 
        MODIN = GFETOUT + OFFSET - INBUFSIZE; 
        END 
  
      ELSE
        BEGIN 
        MODIN = GFETOUT + OFFSET; 
        END 
  
      RETURN; 
  
      END  # MODIN #
  
    TERM
