I've been re-reading some more tutorials and i'm slowly trying them out, and i'm confused on what appears to be a really simple idea, a rout to clear half the screen. from the tutorial:
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move.w #2,-(a7) ; get physbase (the address of screen memory being displayed on the monitor)
move.l d0,a0 ; a0 points to screen
move.w #200-1,d1 ;
clr.w (a0)+ ; all 0 means colour 0 :)
in theory, according to the tutorial, this should load the screen address to a0, then clear 160 pixels, then add 160 to the screen address to jump to the next line, then loop 200 times.
but when I run it, it crashes with two bombs
i'm obviously missing something, the question is, what ?