Skip to navigation

Elite on the BBC Micro and NES

Dashboard: COMPAS

[Acorn Electron version]

Name: COMPAS [Show more] Type: Subroutine Category: Dashboard Summary: Update the compass
Context: See this subroutine in context in the source code Variations: See code variations for this subroutine in the different versions References: This subroutine is called as follows: * DIALS (Part 4 of 4) calls COMPAS
.COMPAS JSR DOT \ Call DOT to redraw (i.e. remove) the current compass \ dot LDA SSPR \ If we are inside the space station safe zone, jump to BNE SP1 \ SP1 to draw the space station on the compass JSR SPS1 \ Otherwise we need to draw the planet on the compass, \ so first call SPS1 to calculate the vector to the \ planet and store it in XX15 JMP SP2 \ Jump to SP2 to draw XX15 on the compass, returning \ from the subroutine using a tail call