further screen code improvements

c64/kernal/screen/chrout_screen_del.s

@@ -13,7 +13,6 @@ chrout_screen_DEL:
 !:
 	// ldx PNTR
 	jsr screen_get_clipped_PNTR
-	cpy #$00
 	bne chrout_screen_del_column_non_0
 
 	// FALLTROUGH
@@ -31,12 +30,10 @@ chrout_screen_del_column_0:
 	// Update PNT and USER pointers
 	jsr screen_calculate_PNT_USER
 
-	// Put space character at the current cursor position
+	// Put space character at the current cursor position (do not clear the color!)
 	ldy #39
 	lda #$20
 	sta (PNT),y
-	
-	// XXX should we clear the color too?
 
 	// Finish with recalculating all the variables
 	jmp chrout_screen_calc_lptr_done

c64/kernal/screen/chrout_screen_ins.s

@@ -4,7 +4,8 @@
 //
 
 
-// YYY does not work properly on growing logical line
+// YYY does not work properly when insertion no longer possible
+// YYY does not work properlyy in second part of logical line
 
 
 chrout_screen_INS:
@@ -25,6 +26,7 @@ chrout_screen_INS:
 chrout_screen_ins_possible:
 
 	// Move chars towards end of the line
+	jsr screen_calculate_PNT_USER
 	jsr screen_get_logical_line_end_ptr
 !:
 	// Note: While the following routine is obvious to any skilled

c64/kernal/screen/screen_get_logical_line_end_ptr.s

@@ -6,11 +6,10 @@ screen_get_logical_line_end_ptr:
 	cpy #24
 	bcs screen_get_logical_line_end_39 // last line of the screen
 	
-	lda LDTBL, y
+	lda LDTBL+0, y
 	bpl screen_get_logical_line_end_39 // current line continues previous one
 	
-	iny
+	lda LDTBL+1, y
-	lda LDTBL, y
 	bmi screen_get_logical_line_end_39 // current line is not continued
 	
 	// FALLTROUGH