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trønderen wrote:

Or do you follow the tradition from 50 years ago, with every instruction/statement left justified?

raster_irq: {
	lda flag
	and #popup_on
	bne bottom		// popup is active

	lda $d012
	cmp #raster_irq_bottom_line
	bcc top

bottom:
	lda #charset2	// set secondary charset (for bottom half of the screen)
	sta $d018

	lda #raster_irq_top_line
	sta $d012

	jmp end

top:		
	lda #charset1	// set primary charset (for top half of the screen)
	sta $d018

	lda #raster_irq_bottom_line
	sta $d012

end:
	asl $d019		// clear pending
	jmp $ea31		// finish interrupt
}

Kornfeld Eliyahu Peter wrote:

because the way assembly flow works...

// if
	lda $d012
	cmp #raster_irq_bottom_line
	bcc top

// true branch
bottom:
    	lda #charset2	// set secondary charset (for bottom half of the screen)
    	sta $d018

    	lda #raster_irq_top_line
    	sta $d012

	jmp end

// false branch
top:		
    	lda #charset1	// set primary charset (for top half of the screen)
    	sta $d018

    	lda #raster_irq_bottom_line
    	sta $d012

// end if
end:

OriginalGriff wrote:

column zero starts were a label, column 7 started an opcode, column 15 was a parameter.

jsc42 wrote:

if you (or, more commonly, the computer operator) accidentally dropped the deck of cards and you (always the programmer) had to re-order them back into their original sequence.