o<surface_test> sub
  ;(MSG, SURFACE_TEST.NGC)
  M64 P0  (turn off compensation)
  ;T1 M6 (Install probe)
  #<x0> = #3050 ;(debug, x0: [#<x0>])
  #<y0> = #3051 ;(debug, y0: [#<y0>])
  #<height> = #3052 ;(debug, height: [#<height>])
  #<width> = #3053 ;(debug, width: [#<width>])
  #<step> = #3054 ;(debug, step: [#<step>])
  #<search_feed> = #3055 ;(debug, search_feed: [#<search_feed>])
  #<latch_feed> = #3056 ;(debug, latch_feed: [#<latch_feed>])
  #<safe_z> = #3057 ;(debug, safe_z: [#<safe_z>])
  #<search_z> = #3058 ;(debug, search_z: [#<search_z>])
           
  ;(PROBEOPEN filename.txt)

  G0 Z#<safe_z>
  #<y> = #<y0>
  o101 while [#<y> LT #<height>+#<y0>]
    #<x> = #<x0>
    o102 while [#<x> LE #<width>+#<x0>]
     G0 X#<x> Y#<y>
      G38.2 Z#<search_z> F#<search_feed>
      G0 Z#<safe_z>
      #<x> = [#<x>+#<step>]
    o102 endwhile
    
    #<y> = [#<y>+#<step>]
    #<x> = [#<x0>+#<width>]
    
    o103 while [#<x> GE #<x0>]
     G0 X#<x> Y#<y>
      G38.2 Z#<search_z> F#<search_feed>
      G0 Z#<safe_z>
      #<x> = [#<x>-#<step>]
    o103 endwhile
    
    #<y> = [#<y>+#<step>]
  o101 endwhile

  ;(PROBECLOSE)
o<surface_test> endsub

M2