Index: tools/smaz.adb
==================================================================
--- tools/smaz.adb
+++ tools/smaz.adb
@@ -49,10 +49,16 @@
         (Nothing,
          Decode,
          Encode,
          Evaluate);
    end Actions;
+
+   package Algorithms is
+      type Enum is
+        (Base_256,
+         Base_256_Retired);
+   end Algorithms;
 
    package Dict_Sources is
       type Enum is
         (S_Expression,
          Text_List,
@@ -59,11 +65,12 @@
          Unoptimized_Text_List);
    end Dict_Sources;
 
    package Options is
       type Id is
-        (Output_Ada_Dict,
+        (Base_256,
+         Output_Ada_Dict,
          Dictionary_Input,
          Decode,
          Encode,
          Evaluate,
          Filter_Threshold,
@@ -73,10 +80,11 @@
          Sx_Dict_Output,
          Min_Sub_Size,
          Max_Sub_Size,
          Dict_Size,
          Max_Pending,
+         Base_256_Retired,
          Stat_Output,
          No_Stat_Output,
          Text_List_Input,
          Fast_Text_Input,
          Max_Word_Size,
@@ -88,10 +96,11 @@
    end Options;
 
    package Getopt is new Natools.Getopt_Long (Options.Id);
 
    type Callback is new Getopt.Handlers.Callback with record
+      Algorithm : Algorithms.Enum := Algorithms.Base_256;
       Display_Help : Boolean := False;
       Need_Dictionary : Boolean := False;
       Stat_Output : Boolean := False;
       Sx_Output : Boolean := False;
       Sx_Dict_Output : Boolean := False;
@@ -1029,19 +1038,26 @@
          when Options.Vlen_Verbatim =>
             Handler.Vlen_Verbatim := True;
 
          when Options.No_Vlen_Verbatim =>
             Handler.Vlen_Verbatim := False;
+
+         when Options.Base_256 =>
+            Handler.Algorithm := Algorithms.Base_256;
+
+         when Options.Base_256_Retired =>
+            Handler.Algorithm := Algorithms.Base_256_Retired;
       end case;
    end Option;
 
 
    function Getopt_Config return Getopt.Configuration is
       use Getopt;
       use Options;
       R : Getopt.Configuration;
    begin
+      R.Add_Option ("base-256",      '2', No_Argument,       Base_256);
       R.Add_Option ("ada-dict",      'A', Optional_Argument, Output_Ada_Dict);
       R.Add_Option ("decode",        'd', No_Argument,       Decode);
       R.Add_Option ("dict",          'D', No_Argument,       Dictionary_Input);
       R.Add_Option ("encode",        'e', No_Argument,       Encode);
       R.Add_Option ("evaluate",      'E', No_Argument,       Evaluate);
@@ -1052,10 +1068,11 @@
       R.Add_Option ("sx-dict",       'L', No_Argument,       Sx_Dict_Output);
       R.Add_Option ("min-substring", 'm', Required_Argument, Min_Sub_Size);
       R.Add_Option ("max-substring", 'M', Required_Argument, Max_Sub_Size);
       R.Add_Option ("dict-size",     'n', Required_Argument, Dict_Size);
       R.Add_Option ("max-pending",   'N', Required_Argument, Max_Pending);
+      R.Add_Option ("retired",       'R', No_Argument,       Base_256_Retired);
       R.Add_Option ("stats",         's', No_Argument,       Stat_Output);
       R.Add_Option ("no-stats",      'S', No_Argument,       No_Stat_Output);
       R.Add_Option ("text-list",     't', No_Argument,       Text_List_Input);
       R.Add_Option ("fast-text-list", 'T', No_Argument,       Fast_Text_Input);
       R.Add_Option ("max-word-len",  'W', Required_Argument, Max_Word_Size);
@@ -1234,10 +1251,20 @@
 
             when Options.No_Vlen_Verbatim =>
                New_Line (Output);
                Put_Line (Output, Indent & Indent
                  & "Disable variable-length verbatim in built dictionary");
+
+            when Options.Base_256 =>
+               New_Line (Output);
+               Put_Line (Output, Indent & Indent
+                 & "Use base-256 implementation (default)");
+
+            when Options.Base_256_Retired =>
+               New_Line (Output);
+               Put_Line (Output, Indent & Indent
+                 & "Use retired base-256 implementation");
          end case;
       end loop;
    end Print_Help;
 
 
@@ -1304,8 +1331,14 @@
          Parser.Next;
          Natools.Smaz_Tools.Read_List (Input_Data, Parser);
       end if;
    end Read_Input_List;
 
-   Dict_256.Process (Handler, Input_List, Input_Data, Handler.Score_Method);
+   case Handler.Algorithm is
+      when Algorithms.Base_256 =>
+         Dict_256.Process
+           (Handler, Input_List, Input_Data, Handler.Score_Method);
+      when Algorithms.Base_256_Retired =>
+         raise Program_Error with "Not implented yet";
+   end case;
 
 end Smaz;