diff --git a/utility.h65 b/utility.h65
index 640dce7..0fd8799 100644
--- a/utility.h65
+++ b/utility.h65
@@ -7,6 +7,34 @@ INCLUDE_UTILITY = 1
 .feature string_escapes
 .feature underline_in_numbers
 
+.macro DEBUG_LED_OFF nr
+    pha
+    lda IO1 + IO::RA
+.if nr = 0
+    and #%11111110
+.elseif nr = 1
+    and #%11111101
+.else
+    and #%11111011
+.endif
+    sta IO1 + IO::RA
+    pla
+.endmacro
+
+.macro DEBUG_LED_ON nr
+    pha
+    lda IO1 + IO::RA
+.if nr = 0
+    ora #%00000001
+.elseif nr = 1
+    ora #%00000010
+.else
+    ora #%00000100
+.endif
+    sta IO1 + IO::RA
+    pla
+.endmacro
+
 
 ;;********************************************************************************
 ;; @macro Update a byte in memory using a mask
@@ -17,6 +45,7 @@ INCLUDE_UTILITY = 1
 ;;   xor #value with addr -> only bits that need to flip are 1
 ;;   and result with #mask -> only selected bits that need to flip stay 1
 ;;   xor result with addr -> flips selected bits
+;; @TODO optimize when immediate is used
 ;;********************************************************************************
 .macro MaskedWrite addr,value,mask
     lda value
@@ -123,4 +152,26 @@ _n_genlabel .set 0
     .ident(.sprintf("%s", .string(l1))) = .ident(.sprintf("%s_%s", .string(prefix), .string(l1)))
     ImportZp prefix,l2,l3,l4,l5,l6,l7,l8
 .endmacro
-.endif
+
+
+.import REVERSE_TABLE
+;;********************************************************************************
+;; @macro Reverse a byte
+;; @param reg: The byte to reverse. May be in X, Y or A
+;; @returns A: The reversed byte
+;; @modifies A, X (only when reg = A)
+;;********************************************************************************
+.macro Reverse reg
+    .if .match(reg, A)
+        tax
+        lda REVERSE_TABLE,x
+    .elseif .match(reg, x)
+        lda REVERSE_TABLE,x
+    .elseif .match(reg, y)
+        lda REVERSE_TABLE,y
+    .else
+        .fatal ("Reverse macro got invalid argument. This syntax error is intentional to show the line number")
+    .endif
+.endmacro
+
+.endif  ; guard