diff --git a/desk.acc/a2d.inc b/desk.acc/a2d.inc
index 3d3d566..d9164ec 100644
--- a/desk.acc/a2d.inc
+++ b/desk.acc/a2d.inc
@@ -52,8 +52,8 @@ A2D_QUERY_SCREEN        := $03  ; Get screen state
         ;; .word top
         ;; .addr addr           A2D_SCREEN_ADDR
         ;; .word stride         A2D_SCREEN_STRIDE
-        ;; .word hoffset
-        ;; .word voffset
+        ;; .word hoff
+        ;; .word voff
         ;; .word width          560-1
         ;; .word height         192-1
         ;; .res 8 pattern
@@ -64,7 +64,7 @@ A2D_QUERY_SCREEN        := $03  ; Get screen state
         ;; .byte hthick         horizontal pen thickness
         ;; .byte vthick         vertical pen thickness
         ;; .byte 0              ??? fill mode?
-        ;; .byte tmsk           AND mask for text, default $7F
+        ;; .byte tmask          AND mask for text, default $7F
         ;; .addr font           A2D_DEFAULT_FONT
 
 A2D_SET_STATE   := $04          ; Set full drawing state
@@ -73,8 +73,8 @@ A2D_SET_STATE   := $04          ; Set full drawing state
         ;; .word top
         ;; .addr addr           A2D_SCREEN_ADDR
         ;; .word stride         A2D_SCREEN_STRIDE
-        ;; .word hoffset        pixels scrolled
-        ;; .word voffset
+        ;; .word hoff           pixels scrolled
+        ;; .word voff
         ;; .word width          pixels
         ;; .word height
         ;; .res 8 pattern
@@ -85,7 +85,7 @@ A2D_SET_STATE   := $04          ; Set full drawing state
         ;; .byte hthick         horizontal pen thickness
         ;; .byte vthick         vertical pen thickness
         ;; .byte 0              ??? fill mode?
-        ;; .byte tmsk           AND mask for text, default $7F
+        ;; .byte tmask          AND mask for text, default $7F
         ;; .addr font           A2D_DEFAULT_FONT
 
         ;; $05 used in DeskTop but not DAs - icon click
@@ -97,14 +97,14 @@ A2D_SET_BOX   := $06            ; Set just the drawing box, subset of full state
         ;; .word top
         ;; .addr addr           A2D_SCREEN_ADDR ($2000)
         ;; .word stride         A2D_SCREEN_STRIDE ($80)
-        ;; .word hoffset        pixels scrolled
-        ;; .word voffset
+        ;; .word hoff           pixels scrolled
+        ;; .word voff
         ;; .word width          pixels
         ;; .word height
 
 A2D_SET_FILL_MODE := $07
         ;; (input length 1 byte)
-        ;; .byte mode           0 = normal, 6 = xor     (<4, >=4)
+        ;; .byte mode           (>=4 also sets eor mask to $7f)
 
 A2D_SET_PATTERN := $08
         ;; (input length 8 bytes)
@@ -167,8 +167,8 @@ A2D_DRAW_BITMAP := $14          ; Draw pattern
         ;; .addr bitmap         bitmap is 7 bits per byte, 0 = black, 1 = white
         ;; .byte stride         bitmap width in bytes
         ;; .byte 0              ???
-        ;; .word hoffset        offset within bitmap definition
-        ;; .word voffset
+        ;; .word hoff           offset within bitmap definition
+        ;; .word voff
         ;; .word width          pixels
         ;; .word height         pixels
 
@@ -258,8 +258,8 @@ A2D_CREATE_WINDOW := $38
         ;; .word top
         ;; .word screen_addr
         ;; .word screen_stride
-        ;; .word hoffset        pixels scrolled
-        ;; .word voffset
+        ;; .word hoff          pixels scrolled
+        ;; .word voff
         ;; .word width          pixels
         ;; .word height
         ;; .res 8 pattern
@@ -270,7 +270,7 @@ A2D_CREATE_WINDOW := $38
         ;; .byte hthick
         ;; .byte vthick
         ;; .byte 0              ??? fill mode?
-        ;; .byte tmsk           AND mask for text, default $7F
+        ;; .byte tmask          AND mask for text, default $7F
         ;; .addr font           A2D_DEFAULT_FONT
         ;; .addr next           address of next lower window in stack (filled in by call)
 
@@ -413,7 +413,7 @@ A2D_CZP_OVERWRITE       := 0
 ;;; Used in various state blocks
 A2D_DEFAULT_MSKAND      := $FF
 A2D_DEFAULT_MSKOR       := $00
-A2D_DEFAULT_TMSK        := $7F
+A2D_DEFAULT_TMASK       := $7F
 
 ;;; ==================================================
 
diff --git a/desk.acc/a2d.md b/desk.acc/a2d.md
index 30546ba..f3e219e 100644
--- a/desk.acc/a2d.md
+++ b/desk.acc/a2d.md
@@ -19,8 +19,8 @@ The _box_ block is reused in several places. It has the following structure:
   .word top            pixels from screen top edge
   .addr addr           A2D_SCREEN_ADDR ($2000)
   .word stride         A2D_SCREEN_STRIDE ($80)
-  .word hoffset        pixels scrolled left
-  .word voffset        pixels scrolled up
+  .word hoff           pixels scrolled left
+  .word voff           pixels scrolled up
   .word width          pixels wide
   .word height         pixels tall
 ```
diff --git a/desk.acc/calc_fixed.s b/desk.acc/calc_fixed.s
index 89aef2b..72f75f7 100644
--- a/desk.acc/calc_fixed.s
+++ b/desk.acc/calc_fixed.s
@@ -242,8 +242,8 @@ top:    .word   row1_top - border_lt
 bitmap: .addr   button_bitmap
 stride: .byte   bitmap_stride
         .byte   0               ; ???
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   button_width + border_lt + border_br
 height: .word   button_height + border_lt + border_br
 label:  .byte   'c'
@@ -257,8 +257,8 @@ top:    .word   row1_top - border_lt
 bitmap: .addr   button_bitmap
 stride: .byte   bitmap_stride
         .byte   0               ; ???
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   button_width + border_lt + border_br
 height: .word   button_height + border_lt + border_br
 label:  .byte   'e'
@@ -272,8 +272,8 @@ top:    .word   row1_top - border_lt
 bitmap: .addr   button_bitmap
 stride: .byte   bitmap_stride
         .byte   0               ; ???
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   button_width + border_lt + border_br
 height: .word   button_height + border_lt + border_br
 label:  .byte   '='
@@ -287,8 +287,8 @@ top:    .word   row1_top - border_lt
 bitmap: .addr   button_bitmap
 stride: .byte   bitmap_stride
         .byte   0               ; ???
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   button_width + border_lt + border_br
 height: .word   button_height + border_lt + border_br
 label:  .byte   '*'
@@ -302,8 +302,8 @@ top:    .word   row2_top - border_lt
 bitmap: .addr   button_bitmap
 stride: .byte   bitmap_stride
         .byte   0               ; ???
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   button_width + border_lt + border_br
 height: .word   button_height + border_lt + border_br
 label:  .byte   '7'
@@ -317,8 +317,8 @@ top:    .word   row2_top - border_lt
 bitmap: .addr   button_bitmap
 stride: .byte   bitmap_stride
         .byte   0               ; ???
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   button_width + border_lt + border_br
 height: .word   button_height + border_lt + border_br
 label:  .byte   '8'
@@ -332,8 +332,8 @@ top:    .word   row2_top - border_lt
 bitmap: .addr   button_bitmap
 stride: .byte   bitmap_stride
         .byte   0               ; ???
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   button_width + border_lt + border_br
 height: .word   button_height + border_lt + border_br
 label:  .byte   '9'
@@ -347,8 +347,8 @@ top:    .word   row2_top - border_lt
 bitmap: .addr   button_bitmap
 stride: .byte   bitmap_stride
         .byte   0               ; ???
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   button_width + border_lt + border_br
 height: .word   button_height + border_lt + border_br
 label:  .byte   '/'
@@ -362,8 +362,8 @@ top:    .word   row3_top - border_lt
 bitmap: .addr   button_bitmap
 stride: .byte   bitmap_stride
         .byte   0               ; ???
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   button_width + border_lt + border_br
 height: .word   button_height + border_lt + border_br
 label:  .byte   '4'
@@ -377,8 +377,8 @@ top:    .word   row3_top - border_lt
 bitmap: .addr   button_bitmap
 stride: .byte   bitmap_stride
         .byte   0               ; ???
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   button_width + border_lt + border_br
 height: .word   button_height + border_lt + border_br
 label:  .byte   '5'
@@ -392,8 +392,8 @@ top:    .word   row3_top - border_lt
 bitmap: .addr   button_bitmap
 stride: .byte   bitmap_stride
         .byte   0               ; ???
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   button_width + border_lt + border_br
 height: .word   button_height + border_lt + border_br
 label:  .byte   '6'
@@ -407,8 +407,8 @@ top:    .word   row3_top - border_lt
 bitmap: .addr   button_bitmap
 stride: .byte   bitmap_stride
         .byte   0               ; ???
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   button_width + border_lt + border_br
 height: .word   button_height + border_lt + border_br
 label:  .byte   '-'
@@ -422,8 +422,8 @@ top:    .word   row4_top - border_lt
 bitmap: .addr   button_bitmap
 stride: .byte   bitmap_stride
         .byte   0               ; ???
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   button_width + border_lt + border_br
 height: .word   button_height + border_lt + border_br
 label:  .byte   '1'
@@ -437,8 +437,8 @@ top:    .word   row4_top - border_lt
 bitmap: .addr   button_bitmap
 stride: .byte   bitmap_stride
         .byte   0               ; ???
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   button_width + border_lt + border_br
 height: .word   button_height + border_lt + border_br
 label:  .byte   '2'
@@ -452,8 +452,8 @@ top:    .word   row4_top - border_lt
 bitmap: .addr   button_bitmap
 stride: .byte   bitmap_stride
         .byte   0               ; ???
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   button_width + border_lt + border_br
 height: .word   button_height + border_lt + border_br
 label:  .byte   '3'
@@ -467,8 +467,8 @@ top:    .word   row5_top - border_lt
 bitmap: .addr   wide_button_bitmap
 stride: .byte   8                   ; bitmap_stride (bytes)
         .byte   0               ; ???
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   49                      ; 0 is extra wide
 height: .word   button_height + border_lt + border_br
 label:  .byte   '0'
@@ -482,8 +482,8 @@ top:    .word   row5_top - border_lt
 bitmap: .addr   button_bitmap
 stride: .byte   bitmap_stride
         .byte   0               ; ???
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   button_width + border_lt + border_br
 height: .word   button_height + border_lt + border_br
 label:  .byte   '.'
@@ -497,8 +497,8 @@ top:    .word   row4_top - border_lt
 bitmap: .addr   tall_button_bitmap
 stride: .byte   bitmap_stride
         .byte   0               ; ???
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   button_width + border_lt + border_br
 height: .word   27              ; + is extra tall
 label:  .byte   '+'
@@ -698,8 +698,8 @@ top:    .word   $FFF7           ; overwritten
 bitmap:.addr   pixels
 stride: .byte   1
         .byte   0               ; ???
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   6
 height: .word   5
         ;;  (not part of struct, but not referenced outside)
@@ -711,14 +711,13 @@ pixels: .byte   px(%1000001)
         .byte   px(%1001001)
 .endproc
 
-        ;; param block for a QUERY_SCREEN and SET_STATE calls, and ref'd in QUERY_STATE call
 .proc state_params
 left:   .word   0
 top:    .word   0
-saddr:  .word   0
+addr:   .word   0
 stride: .word   0
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   0
 height: .word   0
 pattern:.res    8, 0
@@ -728,12 +727,13 @@ xpos:   .word   0
 ypos:   .word   0
 hthick: .byte   0
 vthick: .byte   0
-        .byte   0               ; ???
+mode:   .byte   0
 tmask:  .byte   0
 font:   .addr   0
-        .byte   0,0             ; ???
 .endproc
 
+        .byte   0,0             ; ???
+
         menu_bar_height := 13
         screen_width    := 560
         screen_height   := 192
@@ -744,7 +744,7 @@ font:   .addr   0
         .word   menu_bar_height
         .word   A2D_SCREEN_ADDR
         .word   A2D_SCREEN_STRIDE
-        .word   0, 0            ; hoffset/voffset
+        .word   0, 0            ; hoff/voff
         .word   screen_width - 1
         .word   screen_height - menu_bar_height - 2
 .endproc
@@ -781,10 +781,10 @@ w2:     .word   window_width
 h2:     .word   window_height
 left:   .word   default_left
 top:    .word   default_top
-saddr:  .addr   A2D_SCREEN_ADDR
+addr:   .addr   A2D_SCREEN_ADDR
 stride: .word   A2D_SCREEN_STRIDE
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   window_width
 height: .word   window_height
 pattern:.res    8, $FF
@@ -794,7 +794,7 @@ xpos:   .word   0
 ypos:   .word   0
 hthick: .byte   1
 vthick: .byte   1
-        .byte   0               ; ???
+mode:   .byte   0
 tmask:  .byte   0
 font:   .addr   A2D_DEFAULT_FONT
 next:   .addr   0
diff --git a/desk.acc/calculator.s b/desk.acc/calculator.s
index 9915b7d..f1fc5e9 100644
--- a/desk.acc/calculator.s
+++ b/desk.acc/calculator.s
@@ -247,8 +247,8 @@ top:    .word   row1_top - border_lt
 bitmap: .addr   button_bitmap
 stride: .byte   bitmap_stride
         .byte   0               ; ???
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   button_width + border_lt + border_br
 height: .word   button_height + border_lt + border_br
 label:  .byte   'c'
@@ -262,8 +262,8 @@ top:    .word   row1_top - border_lt
 bitmap: .addr   button_bitmap
 stride: .byte   bitmap_stride
         .byte   0               ; ???
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   button_width + border_lt + border_br
 height: .word   button_height + border_lt + border_br
 label:  .byte   'e'
@@ -277,8 +277,8 @@ top:    .word   row1_top - border_lt
 bitmap: .addr   button_bitmap
 stride: .byte   bitmap_stride
         .byte   0               ; ???
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   button_width + border_lt + border_br
 height: .word   button_height + border_lt + border_br
 label:  .byte   '='
@@ -292,8 +292,8 @@ top:    .word   row1_top - border_lt
 bitmap: .addr   button_bitmap
 stride: .byte   bitmap_stride
         .byte   0               ; ???
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   button_width + border_lt + border_br
 height: .word   button_height + border_lt + border_br
 label:  .byte   '*'
@@ -307,8 +307,8 @@ top:    .word   row2_top - border_lt
 bitmap: .addr   button_bitmap
 stride: .byte   bitmap_stride
         .byte   0               ; ???
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   button_width + border_lt + border_br
 height: .word   button_height + border_lt + border_br
 label:  .byte   '7'
@@ -322,8 +322,8 @@ top:    .word   row2_top - border_lt
 bitmap: .addr   button_bitmap
 stride: .byte   bitmap_stride
         .byte   0               ; ???
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   button_width + border_lt + border_br
 height: .word   button_height + border_lt + border_br
 label:  .byte   '8'
@@ -337,8 +337,8 @@ top:    .word   row2_top - border_lt
 bitmap: .addr   button_bitmap
 stride: .byte   bitmap_stride
         .byte   0               ; ???
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   button_width + border_lt + border_br
 height: .word   button_height + border_lt + border_br
 label:  .byte   '9'
@@ -352,8 +352,8 @@ top:    .word   row2_top - border_lt
 bitmap: .addr   button_bitmap
 stride: .byte   bitmap_stride
         .byte   0               ; ???
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   button_width + border_lt + border_br
 height: .word   button_height + border_lt + border_br
 label:  .byte   '/'
@@ -367,8 +367,8 @@ top:    .word   row3_top - border_lt
 bitmap: .addr   button_bitmap
 stride: .byte   bitmap_stride
         .byte   0               ; ???
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   button_width + border_lt + border_br
 height: .word   button_height + border_lt + border_br
 label:  .byte   '4'
@@ -382,8 +382,8 @@ top:    .word   row3_top - border_lt
 bitmap: .addr   button_bitmap
 stride: .byte   bitmap_stride
         .byte   0               ; ???
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   button_width + border_lt + border_br
 height: .word   button_height + border_lt + border_br
 label:  .byte   '5'
@@ -397,8 +397,8 @@ top:    .word   row3_top - border_lt
 bitmap: .addr   button_bitmap
 stride: .byte   bitmap_stride
         .byte   0               ; ???
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   button_width + border_lt + border_br
 height: .word   button_height + border_lt + border_br
 label:  .byte   '6'
@@ -412,8 +412,8 @@ top:    .word   row3_top - border_lt
 bitmap: .addr   button_bitmap
 stride: .byte   bitmap_stride
         .byte   0               ; ???
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   button_width + border_lt + border_br
 height: .word   button_height + border_lt + border_br
 label:  .byte   '-'
@@ -427,8 +427,8 @@ top:    .word   row4_top - border_lt
 bitmap: .addr   button_bitmap
 stride: .byte   bitmap_stride
         .byte   0               ; ???
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   button_width + border_lt + border_br
 height: .word   button_height + border_lt + border_br
 label:  .byte   '1'
@@ -442,8 +442,8 @@ top:    .word   row4_top - border_lt
 bitmap: .addr   button_bitmap
 stride: .byte   bitmap_stride
         .byte   0               ; ???
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   button_width + border_lt + border_br
 height: .word   button_height + border_lt + border_br
 label:  .byte   '2'
@@ -457,8 +457,8 @@ top:    .word   row4_top - border_lt
 bitmap: .addr   button_bitmap
 stride: .byte   bitmap_stride
         .byte   0               ; ???
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   button_width + border_lt + border_br
 height: .word   button_height + border_lt + border_br
 label:  .byte   '3'
@@ -472,8 +472,8 @@ top:    .word   row5_top - border_lt
 bitmap: .addr   wide_button_bitmap
 stride: .byte   8                   ; bitmap_stride (bytes)
         .byte   0               ; ???
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   49                      ; 0 is extra wide
 height: .word   button_height + border_lt + border_br
 label:  .byte   '0'
@@ -487,8 +487,8 @@ top:    .word   row5_top - border_lt
 bitmap: .addr   button_bitmap
 stride: .byte   bitmap_stride
         .byte   0               ; ???
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   button_width + border_lt + border_br
 height: .word   button_height + border_lt + border_br
 label:  .byte   '.'
@@ -502,8 +502,8 @@ top:    .word   row4_top - border_lt
 bitmap: .addr   tall_button_bitmap
 stride: .byte   bitmap_stride
         .byte   0               ; ???
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   button_width + border_lt + border_br
 height: .word   27              ; + is extra tall
 label:  .byte   '+'
@@ -703,8 +703,8 @@ top:    .word   $FFF7           ; overwritten
 bitmap:.addr   pixels
 stride: .byte   1
         .byte   0               ; ???
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   6
 height: .word   5
         ;;  (not part of struct, but not referenced outside)
@@ -720,10 +720,10 @@ pixels: .byte   px(%1000001)
 .proc state_params
 left:   .word   0
 top:    .word   0
-saddr:  .word   0
+addr:   .word   0
 stride: .word   0
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   0
 height: .word   0
 pattern:.res    8, 0
@@ -733,7 +733,7 @@ xpos:   .word   0
 ypos:   .word   0
 hthick: .byte   0
 vthick: .byte   0
-        .byte   0               ; ???
+mode:   .byte   0
 tmask:  .byte   0
 font:   .addr   0
 .endproc
@@ -747,13 +747,14 @@ font:   .addr   0
 
         ;; params for A2D_SET_BOX when decorating title bar
 .proc screen_box
-        .word   0
-        .word   menu_bar_height
-        .word   A2D_SCREEN_ADDR
-        .word   A2D_SCREEN_STRIDE
-        .word   0, 0            ; hoffset/voffset
-        .word   screen_width - 1
-        .word   screen_height - menu_bar_height - 2
+left:   .word   0
+top:    .word   menu_bar_height
+addr:   .word   A2D_SCREEN_ADDR
+stride: .word   A2D_SCREEN_STRIDE
+hoff:   .word   0
+voff:   .word   0
+width:  .word   screen_width - 1
+height: .word   screen_height - menu_bar_height - 2
 .endproc
 
 .proc fill_mode_normal
@@ -788,10 +789,10 @@ w2:     .word   window_width
 h2:     .word   window_height
 left:   .word   default_left
 top:    .word   default_top
-saddr:  .addr   A2D_SCREEN_ADDR
+addr:   .addr   A2D_SCREEN_ADDR
 stride: .word   A2D_SCREEN_STRIDE
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   window_width
 height: .word   window_height
 pattern:.res    8, $FF
@@ -801,7 +802,7 @@ xpos:   .word   0
 ypos:   .word   0
 hthick: .byte   1
 vthick: .byte   1
-        .byte   0               ; ???
+mode:   .byte   0
 tmask:  .byte   $7f
 font:   .addr   A2D_DEFAULT_FONT
 next:   .addr   0
diff --git a/desk.acc/date.s b/desk.acc/date.s
index c99d84b..90def9b 100644
--- a/desk.acc/date.s
+++ b/desk.acc/date.s
@@ -270,10 +270,10 @@ h2:     .word   $1F4
 .proc box
 left:   .word   180
 top:    .word   50
-saddr:  .addr   A2D_SCREEN_ADDR
+addr:   .addr   A2D_SCREEN_ADDR
 stride: .word   A2D_SCREEN_STRIDE
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   $C7
 height: .word   $40
 .endproc
@@ -284,7 +284,7 @@ xpos:   .word   0
 ypos:   .word   0
 hthick: .byte   4
 vthick: .byte   2
-        .byte   0               ; ???
+mode:   .byte   0
 tmask:  .byte   $7F
 font:   .addr   A2D_DEFAULT_FONT
 next:   .addr   0
diff --git a/desk.acc/puzzle.s b/desk.acc/puzzle.s
index deea433..d7c0812 100644
--- a/desk.acc/puzzle.s
+++ b/desk.acc/puzzle.s
@@ -239,8 +239,8 @@ top:    .word   0
 addr:   .addr   0
 stride: .byte   4
         .byte   0               ; ???
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   27
 height: .word   15
 .endproc
@@ -608,10 +608,10 @@ h2:     .word   default_height
 
 left:   .word   default_left
 top:    .word   default_top
-saddr:  .addr   A2D_SCREEN_ADDR
+addr:   .addr   A2D_SCREEN_ADDR
 stride: .word   A2D_SCREEN_STRIDE
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   default_width
 height: .word   default_height
 
@@ -622,7 +622,7 @@ xpos:   .word   0
 ypos:   .word   0
 hthick: .byte   1
 vthick: .byte   1
-        .byte   0               ; ???
+mode:   .byte   0
 tmask:  .byte   $7F
 font:   .addr   A2D_DEFAULT_FONT
 next:   .addr   0
@@ -632,10 +632,10 @@ next:   .addr   0
 .proc box_cruft                 ; Unknown usage
 left:   .word   default_left
 top:    .word   default_top
-saddr:  .addr   A2D_SCREEN_ADDR
+addr:   .addr   A2D_SCREEN_ADDR
 stride: .word   A2D_SCREEN_STRIDE
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   default_width
 height: .word   default_height
 pattern:.res    8, $FF
@@ -645,7 +645,7 @@ xpos:   .word   0
 ypos:   .word   0
 hthick: .byte   1
 vthick: .byte   1
-        .byte   0               ; ???
+mode:   .byte   0
 tmask:  .byte   $7F
 font:   .addr   A2D_DEFAULT_FONT
         .byte   0,0             ; ???
diff --git a/desk.acc/show_image_file.s b/desk.acc/show_image_file.s
index 6f0a464..fcabf4c 100644
--- a/desk.acc/show_image_file.s
+++ b/desk.acc/show_image_file.s
@@ -209,10 +209,10 @@ h2:     .word   default_height
 .proc box
 left:   .word   default_left
 top:    .word   default_top
-saddr:  .addr   A2D_SCREEN_ADDR
+addr:   .addr   A2D_SCREEN_ADDR
 stride: .word   A2D_SCREEN_STRIDE
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   default_width
 height: .word   default_height
 .endproc
@@ -224,7 +224,7 @@ xpos:   .word   0
 ypos:   .word   0
 hthick: .byte   1
 vthick: .byte   1
-        .byte   0               ; ???
+mode:   .byte   0
 tmask:  .byte   $7F
 font:   .addr   A2D_DEFAULT_FONT
 next:   .addr   0
diff --git a/desk.acc/show_text_file.s b/desk.acc/show_text_file.s
index 35d2d12..5150e64 100644
--- a/desk.acc/show_text_file.s
+++ b/desk.acc/show_text_file.s
@@ -318,10 +318,10 @@ h2:     .word   default_height
 .proc box
 left:   .word   default_left
 top:    .word   default_top
-saddr:  .addr   A2D_SCREEN_ADDR
+addr:   .addr   A2D_SCREEN_ADDR
 stride: .word   A2D_SCREEN_STRIDE
-hoffset:.word   0               ; Also used for A2D_FILL_RECT
-voffset:.word   0
+hoff:   .word   0               ; Also used for A2D_FILL_RECT
+voff:   .word   0
 width:  .word   default_width
 height: .word   default_height
 .endproc
@@ -333,7 +333,7 @@ xpos:   .word   0
 ypos:   .word   0
 hthick: .byte   1
 vthick: .byte   1
-        .byte   0               ; ???
+mode:   .byte   0
 tmask:  .byte   $7F
 font:   .addr   A2D_DEFAULT_FONT
 next:   .addr   0
@@ -345,8 +345,8 @@ left:   .word   default_left
 top:    .word   default_top
 addr:   .word   A2D_SCREEN_ADDR
 stride: .word   A2D_SCREEN_STRIDE
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   default_width
 height: .word   default_height
 .endproc
@@ -580,10 +580,10 @@ title:  jsr     on_title_bar_click
         sec
         lda     window_params::box::width
         sbc     window_width
-        sta     window_params::box::hoffset
+        sta     window_params::box::hoff
         lda     window_params::box::width+1
         sbc     window_width+1
-        sta     window_params::box::hoffset+1
+        sta     window_params::box::hoff+1
 wider:  lda     window_params::hscroll
         ldx     window_width
         cpx     #<max_width
@@ -779,14 +779,14 @@ loop:   inx
         lda     thumb_drag_params::pos
         jsr     mul_by_16
         lda     $06
-        sta     window_params::box::hoffset
+        sta     window_params::box::hoff
         lda     $07
-        sta     window_params::box::hoffset+1
+        sta     window_params::box::hoff+1
         clc
-        lda     window_params::box::hoffset
+        lda     window_params::box::hoff
         adc     window_width
         sta     window_params::box::width
-        lda     window_params::box::hoffset+1
+        lda     window_params::box::hoff+1
         adc     window_width+1
         sta     window_params::box::width+1
         jsr     update_hscroll
@@ -875,11 +875,11 @@ store:  sta     window_params::hspos
         jsr     mul_by_16
         clc
         lda     $06
-        sta     window_params::box::hoffset
+        sta     window_params::box::hoff
         adc     window_width
         sta     window_params::box::width
         lda     $07
-        sta     window_params::box::hoffset+1
+        sta     window_params::box::hoff+1
         adc     window_width+1
         sta     window_params::box::width+1
         rts
@@ -887,26 +887,26 @@ store:  sta     window_params::hspos
 
 .proc update_voffset
         lda     #0
-        sta     window_params::box::voffset
-        sta     window_params::box::voffset+1
+        sta     window_params::box::voff
+        sta     window_params::box::voff+1
         ldx     update_scroll_params::pos
 loop:   beq     adjust_box_height
         clc
-        lda     window_params::box::voffset
+        lda     window_params::box::voff
         adc     #50
-        sta     window_params::box::voffset
+        sta     window_params::box::voff
         bcc     :+
-        inc     window_params::box::voffset+1
+        inc     window_params::box::voff+1
 :       dex
         jmp     loop
 .endproc
 
 .proc adjust_box_height
         clc
-        lda     window_params::box::voffset
+        lda     window_params::box::voff
         adc     window_height
         sta     window_params::box::height
-        lda     window_params::box::voffset+1
+        lda     window_params::box::voff+1
         adc     window_height+1
         sta     window_params::box::height+1
         jsr     calc_line_position
@@ -929,9 +929,9 @@ end:    rts
 .proc update_hscroll
         lda     #2
         sta     update_scroll_params::type
-        lda     window_params::box::hoffset
+        lda     window_params::box::hoff
         sta     $06
-        lda     window_params::box::hoffset+1
+        lda     window_params::box::hoff+1
         sta     $07
         jsr     div_by_16
         sta     update_scroll_params::pos
@@ -962,7 +962,7 @@ end:    rts
 
 .proc clear_window
         A2D_CALL A2D_SET_PATTERN, white_pattern
-        A2D_CALL A2D_FILL_RECT, window_params::box::hoffset
+        A2D_CALL A2D_FILL_RECT, window_params::box::hoff
         A2D_CALL A2D_SET_PATTERN, black_pattern
         rts
 .endproc
@@ -1273,15 +1273,15 @@ end:    rts
 .proc calc_window_size
         sec
         lda     window_params::box::width
-        sbc     window_params::box::hoffset
+        sbc     window_params::box::hoff
         sta     window_width
         lda     window_params::box::width+1
-        sbc     window_params::box::hoffset+1
+        sbc     window_params::box::hoff+1
         sta     window_width+1
 
         sec
         lda     window_params::box::height
-        sbc     window_params::box::voffset
+        sbc     window_params::box::voff
         sta     window_height
         ;; fall through
 .endproc
@@ -1432,8 +1432,8 @@ left:   .word   0
 top:    .word   0
 addr:   .word   A2D_SCREEN_ADDR
 stride: .word   A2D_SCREEN_STRIDE
-hoffset:.word   0
-voffset:.word   0
+hoff:   .word   0
+voff:   .word   0
 width:  .word   80
 height: .word   10
 .endproc
diff --git a/desktop/s1_aux1.s b/desktop/s1_aux1.s
index c45bc2a..2edad45 100644
--- a/desktop/s1_aux1.s
+++ b/desktop/s1_aux1.s
@@ -64,6 +64,8 @@ LD2D0           := $D2D0
 
         sizeof_state := 36
 
+        fill_eor_mask   := $F6
+
 ;;; ==================================================
 ;;; A2D
 
@@ -738,88 +740,104 @@ hires_table_hi:
         .byte   $03,$07,$0B,$0F,$13,$17,$1B,$1F
 
 ;;; ==================================================
+;;; Routines called during FILL_RECT etc based on
+;;; state_fill
 
-L4BA1:  lda     ($84),y
+.proc fillmode0
+        lda     ($84),y
         eor     ($8E),y
-        eor     $F6
+        eor     fill_eor_mask
         and     $89
         eor     ($84),y
-        bcc     L4BB1
-L4BAD:  lda     ($8E),y
-        eor     $F6
-L4BB1:  and     state_mskand
+        bcc     :+
+loop:   lda     ($8E),y
+        eor     fill_eor_mask
+:       and     state_mskand
         ora     state_mskor
         sta     ($84),y
         dey
-        bne     L4BAD
+        bne     loop
+.endproc
+.proc fillmode0a
         lda     ($84),y
         eor     ($8E),y
-        eor     $F6
+        eor     fill_eor_mask
         and     $88
         eor     ($84),y
         and     state_mskand
         ora     state_mskor
         sta     ($84),y
         rts
+.endproc
 
-
+.proc fillmode1
         lda     ($8E),y
-        eor     $F6
+        eor     fill_eor_mask
         and     $89
-        bcc     L4BD7
-L4BD3:  lda     ($8E),y
-        eor     $F6
-L4BD7:  ora     ($84),y
+        bcc     :+
+loop:   lda     ($8E),y
+        eor     fill_eor_mask
+:       ora     ($84),y
         and     state_mskand
         ora     state_mskor
         sta     ($84),y
         dey
-        bne     L4BD3
+        bne     loop
+.endproc
+.proc fillmode1a
         lda     ($8E),y
-        eor     $F6
+        eor     fill_eor_mask
         and     $88
         ora     ($84),y
         and     state_mskand
         ora     state_mskor
         sta     ($84),y
         rts
+.endproc
 
+.proc fillmode2
         lda     ($8E),y
-        eor     $F6
+        eor     fill_eor_mask
         and     $89
-        bcc     L4BFD
-L4BF9:  lda     ($8E),y
-        eor     $F6
-L4BFD:  eor     ($84),y
+        bcc     :+
+loop:   lda     ($8E),y
+        eor     fill_eor_mask
+:       eor     ($84),y
         and     state_mskand
         ora     state_mskor
         sta     ($84),y
         dey
-        bne     L4BF9
+        bne     loop
+.endproc
+.proc fillmode2a
         lda     ($8E),y
-        eor     $F6
+        eor     fill_eor_mask
         and     $88
         eor     ($84),y
         and     state_mskand
         ora     state_mskor
         sta     ($84),y
         rts
+.endproc
 
+.proc fillmode3
         lda     ($8E),y
-        eor     $F6
+        eor     fill_eor_mask
         and     $89
-        bcc     L4C23
-L4C1F:  lda     ($8E),y
-        eor     $F6
-L4C23:  eor     #$FF
+        bcc     :+
+loop:   lda     ($8E),y
+        eor     fill_eor_mask
+:       eor     #$FF
         and     ($84),y
         and     state_mskand
         ora     state_mskor
         sta     ($84),y
         dey
-        bne     L4C1F
-L4C30:  lda     ($8E),y
-        eor     $F6
+        bne     loop
+.endproc
+.proc fillmode3a
+        lda     ($8E),y
+        eor     fill_eor_mask
         and     $88
         eor     #$FF
         and     ($84),y
@@ -827,6 +845,7 @@ L4C30:  lda     ($8E),y
         ora     state_mskor
         sta     ($84),y
         rts
+.endproc
 
 L4C41:  cpx     $98
         beq     L4C49
@@ -1002,10 +1021,7 @@ L4D54:  sta     LOWSCR,y
         ora     #$80
         sta     $89
         ldy     $91
-L4D67:
-L4D68           := * + 1
-L4D69           := * + 2
-        jmp     L4BA1
+L4D67:  jmp     fillmode0       ; modified with fillmode routine
 
 L4D6A:  .byte   $FB
 L4D6B:
@@ -1017,12 +1033,15 @@ L4D73:  .byte   $01,$03,$07,$0F,$1F,$3F,$7F
 L4D7A:  .byte   $7F,$7F,$7F,$7F,$7F,$7F,$7F
 L4D81:  .byte   $7F,$7E,$7C,$78,$70,$60,$40,$00
         .byte   $00,$00,$00,$00,$00,$00
-L4D8F:  .byte   $A1
-L4D90:  .byte   $4B,$CB,$4B,$F1,$4B,$17,$4C,$A1
-        .byte   $4B,$CB,$4B,$F1,$4B,$17,$4C
-L4D9F:  .byte   $BA
-L4DA0:  .byte   $4B,$E2,$4B,$08,$4C,$30,$4C,$BA
-        .byte   $4B,$E2,$4B,$08,$4C,$30,$4C
+
+        ;; Tables used for fill modes
+fill_mode_table:
+        .addr   fillmode0,fillmode1,fillmode2,fillmode3
+        .addr   fillmode0,fillmode1,fillmode2,fillmode3
+
+fill_mode_table_a:
+        .addr   fillmode0a,fillmode1a,fillmode2a,fillmode3a
+        .addr   fillmode0a,fillmode1a,fillmode2a,fillmode3a
 
 ;;; ==================================================
 
@@ -1030,12 +1049,15 @@ SET_FILL_MODE_IMPL:
         lda     state_fill
         ldx     #$00
         cmp     #$04
-        bcc     L4DB9
+        bcc     :+
         ldx     #$7F
-L4DB9:  stx     $F6
+:       stx     fill_eor_mask
         rts
 
-L4DBC:  lda     $F7
+        ;; Called from FILL_RECT, DRAW_TEXT, etc to configure
+        ;; fill routines from mode.
+set_up_fill_mode:
+        lda     $F7
         clc
         adc     $96
         sta     $96
@@ -1064,10 +1086,10 @@ L4DBC:  lda     $F7
         adc     $95
         sta     $95
         lsr     $97
-        beq     L4DF7
+        beq     :+
         jmp     L4E79
 
-L4DF7:  lda     $96
+:       lda     $96
         ror     a
         tax
         lda     L4821,x
@@ -1114,16 +1136,16 @@ L4E34:  sta     $91
         and     $96
         sta     $92
         sta     $96
-        lda     L4D9F,x
-        sta     L4D68
-        lda     L4DA0,x
-        sta     L4D69
+        lda     fill_mode_table_a,x
+        sta     L4D67+1
+        lda     fill_mode_table_a+1,x
+        sta     L4D67+2
         rts
 
-L4E5B:  lda     L4D8F,x
-        sta     L4D68
-        lda     L4D90,x
-        sta     L4D69
+L4E5B:  lda     fill_mode_table,x
+        sta     L4D67+1
+        lda     fill_mode_table+1,x
+        sta     L4D67+2
         rts
 
 L4E68:  lda     $92
@@ -1411,7 +1433,7 @@ FILL_RECT_IMPL:
         jsr     L514C
 L5043:  jsr     L50A9
         bcc     L5015
-        jsr     L4DBC
+        jsr     set_up_fill_mode
         jsr     L4EA9
         jmp     L4CED
 
@@ -1669,7 +1691,7 @@ L51B3:  lda     #$00
         bcs     L51C5
         rts
 
-L51C5:  jsr     L4DBC
+L51C5:  jsr     set_up_fill_mode
         lda     $91
         asl     a
         ldx     $93
@@ -2544,32 +2566,39 @@ L5852:  .byte   $00,$00,$00,$00,$00,$00,$00,$00
 
 ;;; $0B IMPL
 
+;;; SET_FONT ???
+
 L586A:
-        lda     params_addr
+        lda     params_addr     ; set font to passed address
         sta     state_font
         lda     params_addr+1
         sta     state_font+1
-L5872:  ldy     #$00
-L5874:  lda     (state_font),y
+
+L5872:  ldy     #0              ; copy first 3 bytes of font defn (??, ??, height) to $FD-$FF
+:       lda     (state_font),y
         sta     $FD,y
         iny
-        cpy     #$03
-        bne     L5874
-        cmp     #$11
+        cpy     #3
+        bne     :-
+        cmp     #17             ; if height >= 17, skip this next bit
         bcs     L58B7
+
         lda     state_font
         ldx     state_font+1
         clc
-        adc     #$03
+        adc     #3
         bcc     L588C
         inx
-L588C:  sta     $FB
+L588C:  sta     $FB             ; set $FB/$FC to start of widths
         stx     $FC
+
         sec
         adc     $FE
         bcc     L5896
         inx
-L5896:  ldy     #$00
+
+L5896:  ldy     #0              ; loop 0... height-1
+
 L5898:  sta     L58BC,y
         pha
         txa
@@ -2577,25 +2606,24 @@ L5898:  sta     L58BC,y
         pla
         sec
         adc     $FE
-        bcc     L58A7
+        bcc     :+
         inx
-L58A7:  bit     $FD
-        bpl     L58B1
+:       bit     $FD
+        bpl     :+
         sec
         adc     $FE
-        bcc     L58B1
+        bcc     :+
         inx
-L58B1:  iny
-        cpy     $FF
+:       iny
+        cpy     $FF             ; =height?
         bne     L5898
         rts
 
 L58B7:  lda     #$83
         jmp     a2d_exit_with_a
 
-L58BC:  .byte   0
+L58BC:  .byte   $00,$00,$00,$00,$00,$00,$00,$00
         .byte   $00,$00,$00,$00,$00,$00,$00,$00
-        .byte   $00,$00,$00,$00,$00,$00,$00
 L58CC:  .byte   $00,$00,$00,$00,$00,$00,$00,$00
         .byte   $00,$00,$00,$00,$00,$00,$00,$00
 
@@ -2697,7 +2725,7 @@ L596B:  sta     $9B
         ldy     $9F
         iny
         bne     L595C
-L5972:  jsr     L4DBC
+L5972:  jsr     set_up_fill_mode
         jsr     L4EA9
         lda     $87
         clc
@@ -3260,10 +3288,10 @@ L5E5A:  lda     L5F1E,x
         ldx     L5E79+1
         jsr     L5EA0
         lda     #$7F
-        sta     $F6
+        sta     fill_eor_mask
         jsr     FILL_RECT_IMPL
         lda     #$00
-        sta     $F6
+        sta     fill_eor_mask
         rts
 
 L5E79:  .addr   $5F42
@@ -3416,8 +3444,8 @@ xpos:   .word   0
 ypos:   .word   0
 hthick: .byte   1
 vthick: .byte   1
-        .byte   0               ; ???
-tmsk:   .byte   0
+mode:   .byte   0
+tmask:  .byte   0
 font:   .addr   0
 .endproc
 
@@ -3881,7 +3909,7 @@ L6348:  lda     $82,x
         dex
         bpl     L6348
         lda     #$7F
-        sta     L5F1E::tmsk
+        sta     L5F1E::tmask
         lda     $87
         sta     L5F1E::font
         lda     $88
@@ -7642,7 +7670,7 @@ L7F66:  pha
         lda     #$04
         sta     L7D74
         ldx     #$0A
-L7F7D:  lda     SPKR
+L7F7D:  lda     SPKR            ; Beep?
         ldy     #$00
 L7F82:  dey
         bne     L7F82
@@ -7754,21 +7782,21 @@ L8056:  jsr     L7EE2
 L805C:  pha
         jsr     L8035
         pla
-        cmp     #$1B
+        cmp     #KEY_ESCAPE
         bne     L8073
-        lda     #$00
+        lda     #0
         sta     L7D80
         sta     L7D7F
         lda     #$80
         sta     L7D81
         rts
 
-L8073:  cmp     #$0D
+L8073:  cmp     #KEY_RETURN
         bne     L807D
         jsr     L7E8C
         jmp     L7EAD
 
-L807D:  cmp     #$0B
+L807D:  cmp     #KEY_UP
         bne     L80A3
 L8081:  dec     L7D7B
         bpl     L8091
@@ -7785,7 +7813,7 @@ L8091:  ldx     L7D7B
         bne     L8081
 L80A0:  jmp     L800F
 
-L80A3:  cmp     #$0A
+L80A3:  cmp     #KEY_DOWN
         bne     L80D0
 L80A7:  inc     L7D7B
         ldx     L7D7A
@@ -7794,7 +7822,7 @@ L80A7:  inc     L7D7B
         cmp     $AA
         bcc     L80BE
         beq     L80BE
-        lda     #$00
+        lda     #0
         sta     L7D7B
 L80BE:  ldx     L7D7B
         beq     L80CD
@@ -7805,9 +7833,9 @@ L80BE:  ldx     L7D7B
         bne     L80A7
 L80CD:  jmp     L800F
 
-L80D0:  cmp     #$15
+L80D0:  cmp     #KEY_RIGHT
         bne     L80EB
-        lda     #$00
+        lda     #0
         sta     L7D7B
         inc     L7D7A
         lda     L7D7A
@@ -7817,9 +7845,9 @@ L80D0:  cmp     #$15
         sta     L7D7A
 L80E8:  jmp     L800F
 
-L80EB:  cmp     #$08
+L80EB:  cmp     #KEY_LEFT
         bne     L8105
-        lda     #$00
+        lda     #0
         sta     L7D7B
         dec     L7D7A
         bmi     L80FC
@@ -9129,7 +9157,8 @@ xpos:   .word   0
 ypos:   .word   0
 hthick: .byte   1
 vthick: .byte   1
-        .byte   $96,$00         ; ???
+mode:   .byte   $96             ; ???
+tmask:  .byte   0
 font:   .addr   A2D_DEFAULT_FONT
 .endproc
 
@@ -9154,8 +9183,8 @@ xpos:   .word   0
 ypos:   .word   0
 hthick: .byte   0
 vthick: .byte   0
-        .byte   0               ; ???
-tmsk:   .byte   0
+mode:   .byte   0
+tmask:  .byte   0
 font:   .addr   0
 .endproc
 
diff --git a/desktop/s2_aux2.s b/desktop/s2_aux2.s
index 13ff521..42d350d 100644
--- a/desktop/s2_aux2.s
+++ b/desktop/s2_aux2.s
@@ -374,7 +374,7 @@ w2:     .word   $1F4
 h2:     .word   $8C
 left:   .word   $4B
 top:    .word   $23
-saddr:  .addr   A2D_SCREEN_ADDR
+addr:   .addr   A2D_SCREEN_ADDR
 stride: .word   A2D_SCREEN_STRIDE
 hoff:   .word   0
 voff:   .word   0
@@ -383,11 +383,12 @@ height: .word   $64
 pattern:.res    8, $FF
 mskand: .byte   A2D_DEFAULT_MSKAND
 mskor:  .byte   A2D_DEFAULT_MSKOR
-        .byte   0,0,0,0         ; ???
+xpos:   .word   0
+ypos:   .word   0
 hthick: .byte   1
 vthick: .byte   1
-        .byte   0               ; ???
-tmsk:   .byte   A2D_DEFAULT_TMSK
+fill:   .byte   0
+tmask:  .byte   A2D_DEFAULT_TMASK
 font:   .addr   A2D_DEFAULT_FONT
 next:   .addr   0
 .endproc
@@ -409,7 +410,7 @@ w2:     .word   $1F4
 h2:     .word   $8C
 left:   .word   $19
 top:    .word   $14
-saddr:  .addr   A2D_SCREEN_ADDR
+addr:   .addr   A2D_SCREEN_ADDR
 stride: .word   A2D_SCREEN_STRIDE
 hoff:   .word   0
 voff:   .word   0
@@ -418,11 +419,12 @@ height: .word   $99
 pattern:.res    8, $FF
 mskand: .byte   A2D_DEFAULT_MSKAND
 mskor:  .byte   A2D_DEFAULT_MSKOR
-        .byte   0,0,0,0         ; ???
+xpos:   .word   0
+ypos:   .word   0
 hthick: .byte   1
 vthick: .byte   1
-        .byte   0               ; ???
-tmsk:   .byte   A2D_DEFAULT_TMSK
+mode:   .byte   0
+tmask:  .byte   A2D_DEFAULT_TMASK
 font:   .addr   A2D_DEFAULT_FONT
 next:   .addr   0
 .endproc
@@ -444,7 +446,7 @@ w2:     .word   $64
 h2:     .word   $46
 left:   .word   $35
 top:    .word   $32
-saddr:  .addr   A2D_SCREEN_ADDR
+addr:   .addr   A2D_SCREEN_ADDR
 stride: .word   A2D_SCREEN_STRIDE
 hoff:   .word   0
 voff:   .word   0
@@ -453,11 +455,12 @@ height: .word   $46
 pattern:.res    8, $FF
 mskand: .byte   A2D_DEFAULT_MSKAND
 mskor:  .byte   A2D_DEFAULT_MSKOR
-        .byte   0,0,0,0         ; ???
+xpos:   .word   0
+ypos:   .word   0
 hthick: .byte   1
 vthick: .byte   1
-        .byte   0               ; ???
-tmsk:   .byte   A2D_DEFAULT_TMSK
+mode:   .byte   0
+tmask:  .byte   A2D_DEFAULT_TMASK
 font:   .addr   A2D_DEFAULT_FONT
 next:   .addr   0
 .endproc
@@ -479,7 +482,7 @@ w2:     .word   $1F4
 h2:     .word   $8C
 left:   .word   $50
 top:    .word   $28
-saddr:  .addr   A2D_SCREEN_ADDR
+addr:   .addr   A2D_SCREEN_ADDR
 stride: .word   A2D_SCREEN_STRIDE
 hoff:   .word   0
 voff:   .word   0
@@ -488,11 +491,12 @@ height: .word   $6E
 pattern:.res    8, $FF
 mskand: .byte   A2D_DEFAULT_MSKAND
 mskor:  .byte   A2D_DEFAULT_MSKOR
-        .byte   0,0,0,0         ; ???
+xpos:   .word   0
+ypos:   .word   0
 hthick: .byte   1
 vthick: .byte   1
-        .byte   0               ; ???
-tmsk:   .byte   A2D_DEFAULT_TMSK
+mode:   .byte   0
+tmask:  .byte   A2D_DEFAULT_TMASK
 font:   .addr   A2D_DEFAULT_FONT
 next:   .addr   0
 .endproc
@@ -514,7 +518,7 @@ w2:     .word   $1F4
 h2:     .word   $8C
 left:   .word   $69
 top:    .word   $19
-saddr:  .addr   A2D_SCREEN_ADDR
+addr:   .addr   A2D_SCREEN_ADDR
 stride: .word   A2D_SCREEN_STRIDE
 hoff:   .word   0
 voff:   .word   0
@@ -523,11 +527,12 @@ height: .word   $6E
 pattern:.res    8, $FF
 mskand: .byte   A2D_DEFAULT_MSKAND
 mskor:  .byte   A2D_DEFAULT_MSKOR
-        .byte   0,0,0,0         ; ???
+xpos:   .word   0
+ypos:   .word   0
 hthick: .byte   1
 vthick: .byte   1
-        .byte   0               ; ???
-tmsk:   .byte   A2D_DEFAULT_TMSK
+mode:   .byte   0
+tmask:  .byte   A2D_DEFAULT_TMASK
 font:   .addr   A2D_DEFAULT_FONT
 next:   .addr   0
 .endproc
@@ -868,7 +873,7 @@ w2:     .word   545
 h2:     .word   175
 left:   .word   20
 top:    .word   27
-saddr:  .addr   A2D_SCREEN_ADDR
+addr:   .addr   A2D_SCREEN_ADDR
 stride: .word   A2D_SCREEN_STRIDE
 hoff:   .word   0
 voff:   .word   0
@@ -877,11 +882,12 @@ height: .word   120
 pattern:.res    8, $FF
 mskand: .byte   A2D_DEFAULT_MSKAND
 mskor:  .byte   A2D_DEFAULT_MSKOR
-        .byte   0,0,0,0         ; ???
+xpos:   .word   0
+ypos:   .word   0
 hthick: .byte   1
 vthick: .byte   1
-        .byte   0               ; ???
-tmsk:   .byte   A2D_DEFAULT_TMSK
+mode:   .byte   0
+tmask:  .byte   A2D_DEFAULT_TMASK
 font:   .addr   A2D_DEFAULT_FONT
 next:   .addr   0
 .endproc