diff --git a/Code/v1.97/KeyMouseJoy_mac.asm b/Code/v1.97/KeyMouseJoy_mac.asm
index fb256ea..e1af50e 100644
--- a/Code/v1.97/KeyMouseJoy_mac.asm
+++ b/Code/v1.97/KeyMouseJoy_mac.asm
@@ -365,9 +365,10 @@ oldvalue        sbc #$ff
                 lsr ;remove noise bit
                 beq nomove
 
-                cmp #acc ;Acceleration Speed
-                bcc *+3
+                cmp #acc+1 ;Acceleration Speed
+                bcc *+5
                 asl ;X2
+                sbc #acc
 
                 ldx #0
                 cmp #0
@@ -387,8 +388,9 @@ neg             ora #%10000000
                 ror ;remove noise bit
 
                 cmp #256-acc ;Acceleration Speed
-                bcs *+3
+                bcs *+5
                 asl ;X2
+                adc #acc
 
                 ldx #$ff
 
@@ -685,4 +687,4 @@ djr3            lsr           ; dy=1 (move down screen), dy=0 (no y change).
                               ;
                               ; at rts time the carry flag contains the fire
                               ; button state. if c=1 then button not pressed.
-                              ; if c=0 then pressed.
\ No newline at end of file
+                              ; if c=0 then pressed.
diff --git a/Code/v1.97/KeyMouseJoy_win.asm b/Code/v1.97/KeyMouseJoy_win.asm
index eaf0fbd..4a0606a 100644
--- a/Code/v1.97/KeyMouseJoy_win.asm
+++ b/Code/v1.97/KeyMouseJoy_win.asm
@@ -365,9 +365,10 @@ oldvalue        sbc #$ff
                 lsr ;remove noise bit
                 beq nomove
 
-                cmp #acc ;Acceleration Speed
-                bcc *+3
+                cmp #acc+1 ;Acceleration Speed
+                bcc *+5
                 asl ;X2
+                sbc #acc
 
                 ldx #0
                 cmp #0
@@ -387,8 +388,9 @@ neg             ora #%10000000
                 ror ;remove noise bit
 
                 cmp #256-acc ;Acceleration Speed
-                bcs *+3
+                bcs *+5
                 asl ;X2
+                adc #acc
 
                 ldx #$ff
 
@@ -680,4 +682,4 @@ djr3            lsr           ; dy=1 (move down screen), dy=0 (no y change).
                               ;
                               ; at rts time the carry flag contains the fire
                               ; button state. if c=1 then button not pressed.
-                              ; if c=0 then pressed.
\ No newline at end of file
+                              ; if c=0 then pressed.