fix hiding and showing of cursor bugs. Issue #7

c64/kernal/blink_cursor.s

@@ -6,8 +6,8 @@
 	;; colour_under_cursor
 
 show_cursor_if_enabled:
-	bit cursor_blink_disable
-	bpl show_cursor
+	bit cursor_is_visible
+	bmi show_cursor
 	rts
 	
 show_cursor:
@@ -37,7 +37,7 @@ blink_cursor:
 	bne undraw_cursor
 draw_cursor:
 	jsr calculate_screen_line_pointer
-	
+
 	ldy current_screen_x
 	lda (current_screen_line_ptr),y
 	sta cursor_saved_character	
@@ -51,6 +51,7 @@ draw_cursor:
 	
 	lda #1
 	sta cursor_is_visible
+	
 	jmp reset_blink_timer
 
 undraw_cursor:
@@ -79,7 +80,7 @@ disable_cursor:
 	;; FALL THROUGH
 hide_cursor_if_visible:
 	bit cursor_is_visible
-	bpl undraw_cursor
+	bmi undraw_cursor
 	rts
 
 enable_cursor:

c64/kernal/chrout.s

@@ -604,6 +604,9 @@ line_not_linked_del:
 	rts
 	
 screen_advance_to_next_line:
+
+	jsr hide_cursor_if_visible
+	
 	;;  Go to start of line
 	lda #0
 	sta current_screen_x

c64/kernal/cint.s

@@ -10,7 +10,6 @@ cint:
 	;; Initialise cursor blink flags  (Compute's Mapping the 64 p215)
 	lda #$00
 	sta cursor_blink_disable
-	sta cursor_blink_countdown
 
 	;; Set keyboard decode vector  (Compute's Mapping the 64 p215)