diff --git a/compiler/res/prog8lib/cx16/gfx2.p8 b/compiler/res/prog8lib/cx16/gfx2.p8
index 014166cc0..ed2245e4c 100644
--- a/compiler/res/prog8lib/cx16/gfx2.p8
+++ b/compiler/res/prog8lib/cx16/gfx2.p8
@@ -293,17 +293,67 @@ _done
 
     sub vertical_line(uword x, uword y, uword height, ubyte color) {
         when active_mode {
-            1, 5 -> {
-                ; monochrome, either resolution
+            1 -> {
+                ; monochrome, lo-res
+                cx16.r15L = gfx2.plot.bits[x as ubyte & 7]           ; bitmask
+                if color {
+                    if monochrome_dont_stipple_flag {
+                        ; draw continuous line.
+                        position2(x,y,true)
+                        cx16.VERA_CTRL = 0
+                        cx16.VERA_ADDR_H = cx16.VERA_ADDR_H & %00000111 | (11<<4)       ; 40 increment = 1 line in 320 px monochrome
+                        cx16.VERA_CTRL = 1
+                        cx16.VERA_ADDR_H = cx16.VERA_ADDR_H & %00000111 | (11<<4)       ; 40 increment = 1 line in 320 px monochrome
+                        repeat height {
+                            %asm {{
+                                lda  cx16.VERA_DATA0
+                                ora  cx16.r15L
+                                sta  cx16.VERA_DATA1
+                            }}
+                        }
+                    } else {
+                        ; draw stippled line.
+                        if x&1 {
+                            y++
+                            height--
+                        }
+                        position2(x,y,true)
+                        cx16.VERA_CTRL = 0
+                        cx16.VERA_ADDR_H = cx16.VERA_ADDR_H & %00000111 | (12<<4)       ; 80 increment = 2 line in 320 px monochrome
+                        cx16.VERA_CTRL = 1
+                        cx16.VERA_ADDR_H = cx16.VERA_ADDR_H & %00000111 | (12<<4)       ; 80 increment = 2 line in 320 px monochrome
+                        repeat height/2 {
+                            %asm {{
+                                lda  cx16.VERA_DATA0
+                                ora  cx16.r15L
+                                sta  cx16.VERA_DATA1
+                            }}
+                        }
+                    }
+                } else {
+                    position2(x,y,true)
+                    cx16.r15 = ~cx16.r15    ; erase pixels
+                    cx16.VERA_CTRL = 0
+                    cx16.VERA_ADDR_H = cx16.VERA_ADDR_H & %00000111 | (11<<4)       ; 40 increment = 1 line in 320 px monochrome
+                    cx16.VERA_CTRL = 1
+                    cx16.VERA_ADDR_H = cx16.VERA_ADDR_H & %00000111 | (11<<4)       ; 40 increment = 1 line in 320 px monochrome
+                    repeat height {
+                        %asm {{
+                            lda  cx16.VERA_DATA0
+                            and  cx16.r15L
+                            sta  cx16.VERA_DATA1
+                        }}
+                    }
+                }
+            }
+            5 -> {
+                ; monochrome, highres
                 ; note for the 1 bpp modes we can't use vera's auto increment mode because we have to 'or' the pixel data in place.
                 ; TODO use TWO vera adress pointers simultaneously one for reading, one for writing, so auto-increment IS possible
                 position(x,y)
                 cx16.VERA_ADDR_H &= %00000111   ; no auto advance
                 cx16.r15 = gfx2.plot.bits[x as ubyte & 7]           ; bitmask
-                if active_mode==5
-                    cx16.r14 = 640/8
-                else
-                    cx16.r14 = 320/8
+                cx16.r14 = 640/8
                 if color {
                     if monochrome_dont_stipple_flag {
                         repeat height {
diff --git a/examples/test.p8 b/examples/test.p8
index cf3893d89..a20c3d01c 100644
--- a/examples/test.p8
+++ b/examples/test.p8
@@ -4,30 +4,24 @@
 main {
 
     sub start() {
-        gfx2.screen_mode(6)     ; high res 4 colors
+        gfx2.screen_mode(1)     ; lo res monochrome
         gfx2.text_charset(3)
         gfx2.text(10, 10, 1, @"Hello!")
 
         c64.SETTIM(0,0,0)
 
-        repeat 1 {
+        repeat 4 {
             uword xx
-            ; gfx2.monochrome_stipple(true)
-;            for xx in 0 to 639 {
-;                gfx2.vertical_line(xx, 20, 220, 1)
-;            }
-;            gfx2.monochrome_stipple(false)
-            for xx in 0 to 639 {
-                gfx2.vertical_line(xx, 20, 450, 1)
+            gfx2.monochrome_stipple(true)
+            for xx in 0 to 319 {
+                gfx2.vertical_line(xx, 20, 210, 1)
             }
-            for xx in 0 to 639 {
-                gfx2.vertical_line(xx, 20, 450, 2)
+            gfx2.monochrome_stipple(false)
+            for xx in 0 to 319 {
+                gfx2.vertical_line(xx, 20, 210, 1)
             }
-            for xx in 0 to 639 {
-                gfx2.vertical_line(xx, 20, 450, 3)
-            }
-            for xx in 0 to 639 {
-                gfx2.vertical_line(xx, 20, 450, 0)
+            for xx in 0 to 319 {
+                gfx2.vertical_line(xx, 20, 210, 0)
             }
         }