Drawing planets: PL21S

       Name: PL21S                                                   [Show more]
       Type: Subroutine
   Category: Drawing planets
    Summary: Return from a planet/sun-drawing routine with a failure flag
    Context: See this subroutine in context in the source code
 References: This subroutine is called as follows:
             * PLS6 calls PL21S


 This routine is a duplicate of PL21 that is close enough to the PLS6 routine
 for it to be called by a branch instruction.

 Set the C flag and return from the subroutine. This is used to return from a
 planet- or sun-drawing routine with the C flag indicating an overflow in the
 calculation.


.PL21S

 SEC                    \ Set the C flag to indicate an overflow

 RTS                    \ Return from the subroutine