CHKON (Bank 1)PL44 (Bank 1) Name: PL21 [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: * CHKON calls PL21 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. .PL21 SEC ; Set the C flag to indicate an overflow RTS ; Return from the subroutine CHKON (Bank 1)PL44 (Bank 1)