diff --git a/compiler/res/prog8lib/c64/graphics.p8 b/compiler/res/prog8lib/c64/graphics.p8
index 8fbe03f42..90c22073d 100644
--- a/compiler/res/prog8lib/c64/graphics.p8
+++ b/compiler/res/prog8lib/c64/graphics.p8
@@ -12,11 +12,20 @@ graphics {
 
     sub enable_bitmap_mode() {
         ; enable bitmap screen, erase it and set colors to black/white.
-        c64.SCROLY |= %00100000
+        c64.SCROLY = %00111000
+        c64.SCROLX = %00001000
         c64.VMCSB = (c64.VMCSB & %11110000) | %00001000   ; $2000-$3fff
         clear_screen(1, 0)
     }
 
+    sub disable_bitmap_mode() {
+        ; enables text mode, erase the text screen, color white
+        c64.SCROLY = %00011000
+        c64.SCROLX = %00001000
+        c64.VMCSB = (c64.VMCSB & %11110000) | %00000100   ; $1000-$2fff
+        txt.fill_screen(' ', 1)
+    }
+
     sub clear_screen(ubyte pixelcolor, ubyte bgcolor) {
         memset(BITMAP_ADDRESS, 320*200/8, 0)
         txt.fill_screen(pixelcolor << 4 | bgcolor, 0)
diff --git a/compiler/res/prog8lib/cx16/graphics.p8 b/compiler/res/prog8lib/cx16/graphics.p8
index e2bbc4d51..0b9a74559 100644
--- a/compiler/res/prog8lib/cx16/graphics.p8
+++ b/compiler/res/prog8lib/cx16/graphics.p8
@@ -1,5 +1,6 @@
 %target cx16
 %import syslib
+%import textio
 
 ; bitmap pixel graphics module for the CommanderX16
 ; wraps the graphics functions that are in ROM.
@@ -17,6 +18,13 @@ graphics {
         clear_screen(1, 0)
     }
 
+    sub disable_bitmap_mode() {
+        ; enables text mode, erase the text screen, color white
+        void cx16.screen_set_mode(2)
+        txt.fill_screen(' ', 1)     ; TODO doesn't seem to fully clear the text screen after returning from gfx mode
+    }
+
+
     sub clear_screen(ubyte pixelcolor, ubyte bgcolor) {
         cx16.GRAPH_set_colors(pixelcolor, pixelcolor, bgcolor)
         cx16.GRAPH_clear()
diff --git a/compiler/res/prog8lib/test_stack.p8 b/compiler/res/prog8lib/test_stack.p8
index a079cca48..1c1f51c19 100644
--- a/compiler/res/prog8lib/test_stack.p8
+++ b/compiler/res/prog8lib/test_stack.p8
@@ -1,3 +1,4 @@
+%import textio
 
 test_stack {
 
diff --git a/docs/source/todo.rst b/docs/source/todo.rst
index 755605602..43ea74f75 100644
--- a/docs/source/todo.rst
+++ b/docs/source/todo.rst
@@ -2,7 +2,6 @@
 TODO
 ====
 
-- check cpu stack consistency in all examples
 - make it possible to use cpu opcodes such as 'nop' as variable names by prefixing all asm vars with something such as '_'
 - option to load the built-in library files from a directory instead of the embedded ones (for easier library development/debugging)
 - see if we can group some errors together for instance the (now single) errors about unidentified symbols
diff --git a/examples/balloonflight.p8 b/examples/balloonflight.p8
index 38b466b96..ccc7abcb6 100644
--- a/examples/balloonflight.p8
+++ b/examples/balloonflight.p8
@@ -1,6 +1,7 @@
 %target c64
 %import syslib
 %import textio
+%import test_stack
 %zeropage basicsafe
 
 main {
@@ -23,6 +24,9 @@ main {
         ubyte upwards = true
 
         repeat {
+            ;txt.plot(0,0)
+            ;test_stack.test()
+
             ubyte mountain = 223        ; slope upwards
             if active_height < target_height {
                 active_height++
diff --git a/examples/balls.p8 b/examples/balls.p8
index a149af5c0..0bbcfb4f6 100644
--- a/examples/balls.p8
+++ b/examples/balls.p8
@@ -1,4 +1,6 @@
 %import textio
+%import test_stack
+
 %zeropage basicsafe
 
 ; Note: this program is compatible with C64 and CX16.
@@ -86,12 +88,16 @@ main {
         ; read clock
         uword jiffies
         %asm {{
+            stx  P8ZP_SCRATCH_REG
             jsr  c64.RDTIM
             sta  jiffies
             stx  jiffies+1
+            ldx  P8ZP_SCRATCH_REG
         }}
         txt.print("\nbenchmark: ")
         txt.print_uw(jiffies)
         txt.print(" jiffies for 1000 frames.\n")
+
+        ; test_stack.test()
     }
 }
diff --git a/examples/cube3d-float.p8 b/examples/cube3d-float.p8
index a40cee432..7a704ad48 100644
--- a/examples/cube3d-float.p8
+++ b/examples/cube3d-float.p8
@@ -1,5 +1,6 @@
 %import floats
 %import textio
+%import test_stack
 %zeropage basicsafe
 
 ; Note: this program is compatible with C64 and CX16.
@@ -41,6 +42,8 @@ main {
             txt.print(" jiffies/fr = ")
             txt.print_ub(60/timer_jiffies)
             txt.print(" fps")
+
+            ;test_stack.test()
         }
     }
 
diff --git a/examples/cube3d-gfx.p8 b/examples/cube3d-gfx.p8
index 570f60dce..f6311f24e 100644
--- a/examples/cube3d-gfx.p8
+++ b/examples/cube3d-gfx.p8
@@ -1,5 +1,6 @@
 %import syslib
 %import graphics
+%import test_stack
 
 ; Note: this program is compatible with C64 and CX16.
 
@@ -37,6 +38,8 @@ main {
             anglez+=452
 
             wait_a_little_bit()
+
+            ; test_stack.test()
         }
     }
 
diff --git a/examples/cube3d-sprites.p8 b/examples/cube3d-sprites.p8
index be664bdaa..aa5ef2464 100644
--- a/examples/cube3d-sprites.p8
+++ b/examples/cube3d-sprites.p8
@@ -1,6 +1,7 @@
 %target c64
 %import syslib
 %import textio
+%import test_stack
 
 spritedata $2000 {
     ; this memory block contains the sprite data
@@ -95,6 +96,8 @@ main {
             txt.print(" jiffies/fr = ")
             txt.print_ub(60/c64.TIME_LO)
             txt.print(" fps")
+
+            ; test_stack.test()
         }
     }
 
diff --git a/examples/cube3d.p8 b/examples/cube3d.p8
index dd8abda45..5f825bda5 100644
--- a/examples/cube3d.p8
+++ b/examples/cube3d.p8
@@ -1,5 +1,6 @@
 %target c64
 %import syslib
+%import test_stack
 %import textio
 
 main {
@@ -33,6 +34,8 @@ main {
             txt.print_ub(60/c64.TIME_LO)
             txt.print(" fps")
             c64.TIME_LO=0
+
+            ; test_stack.test()
         }
     }
 
diff --git a/examples/cx16/cobramk3-gfx.p8 b/examples/cx16/cobramk3-gfx.p8
index 9e4422e5e..c0442ac41 100644
--- a/examples/cx16/cobramk3-gfx.p8
+++ b/examples/cx16/cobramk3-gfx.p8
@@ -1,5 +1,6 @@
 %target cx16
 %import syslib
+%import test_stack
 %import conv
 
 ; TODO add all other Elite's ships, show their name, advance to next ship on keypress
@@ -41,6 +42,8 @@ main {
             anglex += 217
             angley -= 505
             anglez += 452
+
+            ; test_stack.test()
         }
     }
 
diff --git a/examples/line-circle-gfx.p8 b/examples/line-circle-gfx.p8
index 75a2f8698..f8471254b 100644
--- a/examples/line-circle-gfx.p8
+++ b/examples/line-circle-gfx.p8
@@ -1,4 +1,5 @@
 %import graphics
+%import test_stack
 
 ; Note: this program is compatible with C64 and CX16.
 
@@ -6,8 +7,13 @@ main {
 
     sub start() {
         graphics.enable_bitmap_mode()
+
         draw_lines()
         draw_circles()
+
+        ; graphics.disable_bitmap_mode()
+        ; test_stack.test()
+
         repeat {
         }
     }
diff --git a/examples/line-circle-txt.p8 b/examples/line-circle-txt.p8
index 2783562d6..64f3cc8db 100644
--- a/examples/line-circle-txt.p8
+++ b/examples/line-circle-txt.p8
@@ -1,5 +1,6 @@
 %import textio
 %import syslib
+%import test_stack
 %zeropage basicsafe
 
 ; Note: this program is compatible with C64 and CX16.
@@ -40,6 +41,8 @@ main {
         rect(10, 10, 10, 10, false)
         rect(6, 0, 16, 20, true)
 
+        ; test_stack.test()
+
 
         sub rect(ubyte x1, ubyte y1, ubyte x2, ubyte y2, ubyte fill) {
             ubyte x
diff --git a/examples/mandelbrot-gfx.p8 b/examples/mandelbrot-gfx.p8
index 27a88e49a..d0cc253bf 100644
--- a/examples/mandelbrot-gfx.p8
+++ b/examples/mandelbrot-gfx.p8
@@ -1,5 +1,6 @@
 %import graphics
 %import floats
+%import test_stack
 %zeropage floatsafe
 
 ; Draw a mandelbrot in graphics mode (the image will be 256 x 200 pixels).
@@ -44,6 +45,8 @@ main {
             }
         }
 
+        ; test_stack.test()
+
         repeat {
         }
     }
diff --git a/examples/mandelbrot.p8 b/examples/mandelbrot.p8
index 50fd45f95..983be7a50 100644
--- a/examples/mandelbrot.p8
+++ b/examples/mandelbrot.p8
@@ -1,5 +1,6 @@
 %import textio
 %import floats
+%import test_stack
 %zeropage basicsafe
 
 ; Note: this program is compatible with C64 and CX16.
@@ -57,5 +58,7 @@ main {
         txt.print("finished in ")
         floats.print_f(duration)
         txt.print(" seconds!\n")
+
+        ; test_stack.test()
     }
 }
diff --git a/examples/numbergame.p8 b/examples/numbergame.p8
index eee717b11..61e6621df 100644
--- a/examples/numbergame.p8
+++ b/examples/numbergame.p8
@@ -1,5 +1,6 @@
 %import textio
 %import conv
+%import test_stack
 %zeropage basicsafe
 
 ; The classic number guessing game.
@@ -59,6 +60,8 @@ main {
             txt.print("Thanks for playing, ")
             txt.print(name)
             txt.print(".\n")
+
+            ; test_stack.test()
         }
     }
 }
diff --git a/examples/plasma.p8 b/examples/plasma.p8
index 81d9dc0ed..44044db22 100644
--- a/examples/plasma.p8
+++ b/examples/plasma.p8
@@ -1,5 +1,6 @@
 %target c64
 %import syslib
+%import test_stack
 %import textio
 
 ;  converted from plasma test program for cc65.
@@ -26,7 +27,7 @@ main {
         ; ubyte v = c64.VMCSB
         c64.CIA2PRA = (block & $FC) | (lsb(SCREEN1 >> 14) ^ $03)
 
-        repeat {
+        repeat 100 {
             doplasma(SCREEN1)
             c64.VMCSB = PAGE1
             doplasma(SCREEN2)
@@ -37,6 +38,9 @@ main {
         ;c64.VMCSB = v
         ;c64.CIA2PRA = block
         ;txt.print("done!\n")
+        ;test_stack.test()
+        ;repeat {
+        ;}
     }
 
     ; several variables outside of doplasma to make them retain their value
diff --git a/examples/primes.p8 b/examples/primes.p8
index 91a95e0ac..dacad844e 100644
--- a/examples/primes.p8
+++ b/examples/primes.p8
@@ -1,4 +1,5 @@
 %import textio
+%import test_stack
 %zeropage basicsafe
 
 ; Note: this program is compatible with C64 and CX16.
@@ -26,6 +27,8 @@ main {
         txt.print("number of primes (expected 54): ")
         txt.print_ub(amount)
         txt.chrout('\n')
+
+        ; test_stack.test()
     }
 
 
diff --git a/examples/sorting.p8 b/examples/sorting.p8
index ef9d86f0e..c7d67d2e6 100644
--- a/examples/sorting.p8
+++ b/examples/sorting.p8
@@ -1,4 +1,5 @@
 %import textio
+%import test_stack
 %zeropage basicsafe
 
 ; Note: this program is compatible with C64 and CX16.
@@ -31,6 +32,7 @@ main {
         txt.print("reversed\n")
         print_arrays()
 
+        ;test_stack.test()
         return
 
 
diff --git a/examples/tehtriz.p8 b/examples/tehtriz.p8
index 908af1601..8e021aeda 100644
--- a/examples/tehtriz.p8
+++ b/examples/tehtriz.p8
@@ -10,6 +10,7 @@
 %target c64
 %import syslib
 %import textio
+%import test_stack
 
 
 main {
@@ -67,6 +68,9 @@ waitkey:
             }
 
             drawScore()
+
+            ; txt.plot(0,0)
+            ; test_stack.test()
         }
 
         ubyte key=c64.GETIN()
diff --git a/examples/testforloops.p8 b/examples/testforloops.p8
index 0d907a13a..79fb0b48f 100644
--- a/examples/testforloops.p8
+++ b/examples/testforloops.p8
@@ -1,4 +1,5 @@
 %import textio
+%import test_stack
 %zeropage basicsafe
 
 ; Note: this program is compatible with C64 and CX16.
@@ -963,6 +964,9 @@ main {
             txt.print("ok\n")
         else
             txt.print("fail!!!\n")
+
+
+        test_stack.test()
     }
 
     sub wait_input() {
diff --git a/examples/textelite.p8 b/examples/textelite.p8
index 31e48c16e..71a79494b 100644
--- a/examples/textelite.p8
+++ b/examples/textelite.p8
@@ -1,6 +1,7 @@
 %import textio
 %import conv
 %import diskio
+%import test_stack
 %option no_sysinit
 %zeropage basicsafe
 
@@ -26,6 +27,8 @@ main {
         planet.display(false)
 
         repeat {
+            ; test_stack.test()
+
             str input = "????????"
             txt.print("\nCash: ")
             util.print_10s(ship.cash)
diff --git a/examples/turtle-gfx.p8 b/examples/turtle-gfx.p8
index 688eadbed..08a038069 100644
--- a/examples/turtle-gfx.p8
+++ b/examples/turtle-gfx.p8
@@ -1,6 +1,7 @@
 %target c64
 %import floats
 %import graphics
+%import test_stack
 %zeropage floatsafe
 
 main {
@@ -18,6 +19,8 @@ main {
             turtle.rt(94)
         }
 
+        ; test_stack.test()
+
         repeat {
         }
     }