diff --git a/src/fx/fx.hgr.1bit.fizzle.a b/src/fx/fx.hgr.1bit.fizzle.a
index 75c40a6ae..c2688621b 100755
--- a/src/fx/fx.hgr.1bit.fizzle.a
+++ b/src/fx/fx.hgr.1bit.fizzle.a
@@ -5,22 +5,22 @@
 !to "build/FX/BIT.FIZZLE",plain
 *=$6000
 
-copymasks = $6100                    ; [256 bytes, page-aligned]
-addrs     = $6200                    ; [256 bytes, page-aligned]
+addrs     = $6100                    ; [256 bytes, page-aligned]
+copymasks = $6200                    ; [256 bytes, page-aligned]
 
          jsr   swapzp                ; copy LFSR code to zero page
 
-         inx
-         lda   #1                    ; create copymask lookup table
+         inx                         ; X=0
+         lda   #%00000001            ; create copymask lookup table
 --       ldy   #$20
-         ora   #$80
+         ora   #%10000000
 -        sta   copymasks, x
          inx
          dey
          bne   -
          asl
          bne   --
-
+                                     ; X=0
          clc
 --       ldy   #$20                  ; create address lookup table
          tya
@@ -31,7 +31,7 @@ addrs     = $6200                    ; [256 bytes, page-aligned]
          bne   -
          txa
          bne   --
-
+                                     ; X,Y=0
          jsr   $0                    ; call LFSR code on zero page
 
          lda   $4000                 ; last lousy byte (because LFSR never hits 0)
@@ -44,7 +44,7 @@ swapzp   ldx   #(end-start-1)
          sty   $0, x
          dex
          bpl   -
-         rts
+         rts                         ; X=#$FF
 
 start
 !pseudopc 0 {
diff --git a/src/fx/fx.hgr.2bit.fizzle.a b/src/fx/fx.hgr.2bit.fizzle.a
index 837474628..1631f8e5c 100644
--- a/src/fx/fx.hgr.2bit.fizzle.a
+++ b/src/fx/fx.hgr.2bit.fizzle.a
@@ -10,7 +10,7 @@ copymasks = $6200                    ; [128 bytes, should not cross page boundar
 
          jsr   swapzp                ; copy LFSR code to zero page
 
-         ldx   #0
+         inx                         ; X=0
          lda   #%00000011            ; create copymask lookup table
 --       ldy   #$20
          ora   #%10000000
@@ -21,8 +21,9 @@ copymasks = $6200                    ; [128 bytes, should not cross page boundar
          asl
          asl
          bne   --
+
+         tax                         ; X=0
          clc
-         ldx   #0
 --       ldy   #$20                  ; create address lookup table
          tya
 -        sta   addrs, x
@@ -32,7 +33,7 @@ copymasks = $6200                    ; [128 bytes, should not cross page boundar
          bne   -
          txa
          bne   --
-
+                                     ; X,Y=0
          jsr   $0                    ; call LFSR code on zero page
 
          lda   $4000                 ; last lousy byte (because LFSR never hits 0)
@@ -45,7 +46,7 @@ swapzp   ldx   #(end-start-1)
          sty   $0, x
          dex
          bpl   -
-         rts
+         rts                         ; X=#$FF
 
 start
 !pseudopc 0 {
diff --git a/src/fx/fx.shr.fizzle.a b/src/fx/fx.shr.fizzle.a
index d49050fb8..9c5a20930 100644
--- a/src/fx/fx.shr.fizzle.a
+++ b/src/fx/fx.shr.fizzle.a
@@ -16,7 +16,7 @@ addrs=$A100                          ; [128 bytes, can be anywhere in main memor
          sbc   #1
          dex
          bpl   -
-         inx
+         inx                         ; X=0
 
          sta   $C005                 ; pre-copy SHR SCB and palette
          ldy   #0
@@ -28,13 +28,13 @@ addrs=$A100                          ; [128 bytes, can be anywhere in main memor
          sta   $9F00, y
          iny
          bne   -
-
+                                     ; X,Y=0
          jsr   $0                    ; call LFSR code on zero page
 
          lda   $2000                 ; last lousy byte (because LFSR never hits 0)
          sta   $2000
-
-         sta   $C004                 ; restore and exit
+         sta   $C004
+                                     ; fall through to restore and exit
 swapzp   ldx   #(end-start-1)
 -        ldy   start, x
          lda   $0, x