reached target granularity in screen code

c64/kernal/screen/screen_set_pointer_to_current_line.s

@@ -0,0 +1,35 @@
+	// Put the address of the screen current line
+	// into the pointer at $D1 (PNT).
+	// It must take into account the screen line link table
+	// (Compute's Mapping the 64 p216)
+
+screen_set_pointer_to_current_line:
+	//  Get pointer to start of the screen
+	lda HIBASE
+	sta PNT+1
+	lda #$00
+	sta PNT+0
+
+	// Now advance for the number of lines
+	ldx TBLX
+
+sptcl_l2:
+	// XXX - Should we read the columns per line from
+	// somewhere?
+	ldy #<40
+	// Double line length if line is linked
+	lda LDTBL,x
+	bpl sptcl_l1
+	ldy #<80
+sptcl_l1:
+	tya
+	clc
+	adc PNT+0
+	lda PNT+1
+	adc #>40
+	sta PNT+1
+
+	dex
+	bpl sptcl_l2
+	
+	rts