// Put the address of the screen current line
	// into the pointer at $D1 (current_screen_line_ptr).
	// It must take into account the screen line link table
	// (Compute's Mapping the 64 p216)
set_pointer_to_current_screen_line:
	//  Get pointer to start of the screen
	lda HIBASE
	sta current_screen_line_ptr+1
	lda #$00
	sta current_screen_line_ptr+0

	// Now advance for the number of lines
	ldx current_screen_y

sptcsl_l2:	
	// XXX - Should we read the columns per line from
	// somewhere?
	ldy #<40
	// Double line length if line is linked
	lda screen_line_link_table,x
	bpl sptcsl_l1
	ldy #<80
sptcsl_l1:
	tya
	clc
	adc current_screen_line_ptr+0
	lda current_screen_line_ptr+1
	adc #>40
	sta current_screen_line_ptr+1

	dex
	bpl sptcsl_l2
	
	rts