diff --git a/modflash/AddItem.c b/modflash/AddItem.c
deleted file mode 100644
index ebdb41d..0000000
--- a/modflash/AddItem.c
+++ /dev/null
@@ -1,68 +0,0 @@
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-
-FILE *fi, *fo;
-int i;
-unsigned char mem[0x4004], core;
-unsigned short j, k;
-
-int main(int argc, char *argv[]) {
-  if( argc==1 )
-    printf("\n"
-    "AddItem v0.02, simulates Machine and ROM addition to the ZX-Uno flash image\n\n"
-    "  AddItem        <type> <input_file> <slot>\n\n"
-    "  <type>         ROM or COREX, when 2<=X<=45, i.e. CORE5\n"
-    "  <input_file>   Input .TAP file generate with GenRom\n"
-    "  <slot>         Number of slot from 0 to 63, only when type is ROM\n\n"
-    "All modifications occur in the file FLASH.ZX1\n\n"),
-    exit(0);
-  fo= fopen("FLASH.ZX1", "rb+");
-  if( strstr(argv[1], "CORE")==argv[1] && strlen(argv[1])<=6 && strlen(argv[1])>=5 && argc==3 ){
-    core= (strlen(argv[1])==5 ? argv[1][4] : (argv[1][4]-'0')*10+argv[1][5])-'2';
-    if( core>43 )
-      printf("\nCore number out of range: %d\n", core+2),
-      exit(-1);
-    fi= fopen(argv[2], "rb");
-    if( !fi )
-      printf("\nInput file not found: %s\n", argv[2]),
-      exit(-1);
-    fread(mem, 1, 0x58, fi);
-    fseek(fo, 0x7100+(core<<5), SEEK_SET);
-    fwrite(mem+0x34, 1, 0x20, fo);
-    j= mem[3];
-    fseek(fo, (core>7?0x160000:0xac000)+core*0x54000, SEEK_SET);
-    for ( i=0; i<j; i++ )
-      fread(mem, 1, 0x4004, fi),
-      fwrite(mem, 1, 0x4000, fo);
-  }
-  else if( !strcmp(argv[1], "ROM") && argc==4 ){
-    fi= fopen(argv[3], "rb");
-    if( !fi )
-      printf("\nInput file not found: %s\n", argv[3]),
-      exit(-1);
-    fseek(fo, 0x7000, SEEK_SET);
-    fread(mem, 1, 0x40, fo);
-    for ( i= 0; i<0x40; i++ )
-      if( mem[i]==0xff )
-        break;
-    mem[i]= i;
-    fseek(fo, 0x7000, SEEK_SET);
-    fwrite(mem, 1, 0x40, fo);
-    fread(mem, 1, 0x58, fi);
-    fseek(fo, 0x6000|i<<6, SEEK_SET);
-    k= mem[2]= atoi(argv[2]);
-    fwrite(mem+2,    1, 0x20, fo);
-    fwrite(mem+0x34, 1, 0x20, fo);
-    j= mem[3];
-    for ( i=0; i<j; i++ )
-      fseek(fo, (k<19?0xc000:0x300000)+k*0x4000, SEEK_SET),
-      k= (k+1)&0x3f,
-      fread(mem, 1, 0x4004, fi),
-      fwrite(mem, 1, 0x4000, fo);
-  }
-  else
-    printf("\nInvalid parameters\n"),
-    exit(-1);
-  printf("\nDone\n");
-}
diff --git a/modflash/AddItem.exe b/modflash/AddItem.exe
deleted file mode 100644
index 9fe8fbb..0000000
Binary files a/modflash/AddItem.exe and /dev/null differ
diff --git a/sdk/Makefile b/sdk/Makefile
index c9c1c08..2a3de07 100644
--- a/sdk/Makefile
+++ b/sdk/Makefile
@@ -49,6 +49,7 @@ FCUT		:= fcut$(EXECEXT)
 FPAD		:= fpad$(EXECEXT)
 FPOKE		:= fpoke$(EXECEXT)
 GENROM		:= GenRom$(EXECEXT)
+ADDITEM		:= AddItem$(EXECEXT)
 
 TOOLS:=\
  bin/$(SJASMPLUS) \
@@ -56,7 +57,8 @@ TOOLS:=\
  bin/$(FCUT) \
  bin/$(FPAD) \
  bin/$(FPOKE) \
- bin/$(GENROM)
+ bin/$(GENROM) \
+ bin/$(ADDITEM)
 
 .PHONY: all
 all: $(TOOLS)
diff --git a/sdk/README.md b/sdk/README.md
index b843685..24ed6b5 100644
--- a/sdk/README.md
+++ b/sdk/README.md
@@ -33,6 +33,7 @@ Command | Target
 `make bin/fpad` | **fpad**
 `make bin/fpoke` | **fpoke**
 `make bin/GenRom` | **GenRom**
+`make bin/AddItem` | **AddItem**
 
 To build using MinGW add this parameter for `make` tool:
 
@@ -114,6 +115,7 @@ This has the same behavior as the inclusion of `common.mk` file in a Makefile.
 * fpad
 * fpoke
 * GenRom
+* AddItem
 
 on Windows platform is disabled right now because of presence of precompiled binaries of them in repository.
 *By default* they are not deleted when cleaning.
diff --git a/sdk/bin/.gitignore b/sdk/bin/.gitignore
index b946794..bc459a0 100644
--- a/sdk/bin/.gitignore
+++ b/sdk/bin/.gitignore
@@ -8,3 +8,4 @@ fcut
 fpad
 fpoke
 GenRom
+AddItem
diff --git a/sdk/bin/AddItem.exe b/sdk/bin/AddItem.exe
new file mode 100644
index 0000000..1e0954c
Binary files /dev/null and b/sdk/bin/AddItem.exe differ
diff --git a/sdk/bin/AddItem.exe.license b/sdk/bin/AddItem.exe.license
new file mode 100644
index 0000000..e45abdf
--- /dev/null
+++ b/sdk/bin/AddItem.exe.license
@@ -0,0 +1,11 @@
+SPDX-FileName: AddItem.exe
+
+SPDX-FileType: BINARY
+
+SPDX-FileChecksum: SHA1: 4c0298aa44631d46b241f90471d36775b536d844
+
+SPDX-FileCopyrightText: Copyright (C) 2019, 2021 Antonio Villena
+
+SPDX-License-Identifier: GPL-3.0-only
+
+SPDX-FileComment: AddItem version 0.02 - simulates Machine and ROM addition to the ZX-Uno flash image.
diff --git a/sdk/src/Makefile b/sdk/src/Makefile
index c23ad81..4aa79d9 100644
--- a/sdk/src/Makefile
+++ b/sdk/src/Makefile
@@ -28,6 +28,7 @@ FCUT		:= fcut$(EXECEXT)
 FPAD		:= fpad$(EXECEXT)
 FPOKE		:= fpoke$(EXECEXT)
 GENROM		:= GenRom$(EXECEXT)
+ADDITEM		:= AddItem$(EXECEXT)
 
 TOOLS:= \
  ../bin/$(SJASMPLUS) \
@@ -35,7 +36,8 @@ TOOLS:= \
  ../bin/$(FCUT) \
  ../bin/$(FPAD) \
  ../bin/$(FPOKE) \
- ../bin/$(GENROM)
+ ../bin/$(GENROM) \
+ ../bin/$(ADDITEM)
 
 .PHONY: all
 all: $(TOOLS)
@@ -94,10 +96,14 @@ zx7b/$(ZX7B): | zx7b
 ../bin/$(GENROM): tools/$(GENROM)
 	cp $< $@
 
+../bin/$(ADDITEM): tools/$(ADDITEM)
+	cp $< $@
+
 tools/$(FCUT) \
 tools/$(FPAD) \
 tools/$(FPOKE) \
-tools/$(GENROM): | tools
+tools/$(GENROM) \
+tools/$(ADDITEM): | tools
 	$(MAKE) -w -C $|
 endif
 
diff --git a/sdk/src/tools/.gitignore b/sdk/src/tools/.gitignore
index a088ac8..0e0a00a 100644
--- a/sdk/src/tools/.gitignore
+++ b/sdk/src/tools/.gitignore
@@ -10,3 +10,5 @@ fpoke
 fpoke.exe
 GenRom
 GenRom.exe
+AddItem
+AddItem.exe
diff --git a/sdk/src/tools/AddItem.c b/sdk/src/tools/AddItem.c
new file mode 100644
index 0000000..e0f10e5
--- /dev/null
+++ b/sdk/src/tools/AddItem.c
@@ -0,0 +1,114 @@
+/*
+ * AddItem - simulates Machine and ROM addition to the ZX-Uno flash image.
+ *
+ * Copyright (C) 2019, 2021 Antonio Villena
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 3.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * SPDX-FileCopyrightText: Copyright (C) 2019, 2021 Antonio Villena
+ *
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define PROGRAM "AddItem"
+#define DESCRIPTION "simulates Machine and ROM addition to the ZX-Uno flash image."
+#define VERSION "0.02"
+#define COPYRIGHT "Copyright (C) 2019, 2021 Antonio Villena"
+#define LICENSE \
+"This program is free software: you can redistribute it and/or modify\n" \
+"it under the terms of the GNU General Public License as published by\n" \
+"the Free Software Foundation, version 3."
+#define HOMEPAGE "https://github.com/zxdos/zxuno/"
+
+#define OUTPUT_FILE "FLASH.ZX1"
+
+FILE *fi, *fo;
+int i;
+unsigned char mem[0x4004], core;
+unsigned short j, k;
+
+void show_help() {
+  printf(
+    PROGRAM " version " VERSION " - " DESCRIPTION "\n"
+    COPYRIGHT "\n"
+    LICENSE "\n"
+    "Home page: " HOMEPAGE "\n"
+    "\n"
+    "Usage:\n"
+    "  " PROGRAM "        <type> <input_file> <slot>\n"
+    "\n"
+    "  <type>         ROM or COREX, where 2<=X<=45, i.e. CORE5\n"
+    "  <input_file>   Input .TAP file generated with GenRom\n"
+    "  <slot>         Slot's number from 0 to 63, only when type is ROM\n"
+    "\n"
+    "All modifications occur in the file `" OUTPUT_FILE "'.\n"
+  );
+}
+
+int main(int argc, char *argv[]) {
+  if( argc==1 )
+    show_help(),
+    exit(0);
+  fo= fopen(OUTPUT_FILE, "rb+");
+  if( strstr(argv[1], "CORE")==argv[1] && strlen(argv[1])<=6 && strlen(argv[1])>=5 && argc==3 ){
+    core= (strlen(argv[1])==5 ? argv[1][4] : (argv[1][4]-'0')*10+argv[1][5])-'2';
+    if( core>43 )
+      printf("\nCore number out of range: %d\n", core+2),
+      exit(-1);
+    fi= fopen(argv[2], "rb");
+    if( !fi )
+      printf("\nInput file not found: %s\n", argv[2]),
+      exit(-1);
+    fread(mem, 1, 0x58, fi);
+    fseek(fo, 0x7100+(core<<5), SEEK_SET);
+    fwrite(mem+0x34, 1, 0x20, fo);
+    j= mem[3];
+    fseek(fo, (core>7?0x160000:0xac000)+core*0x54000, SEEK_SET);
+    for ( i=0; i<j; i++ )
+      fread(mem, 1, 0x4004, fi),
+      fwrite(mem, 1, 0x4000, fo);
+  }
+  else if( !strcmp(argv[1], "ROM") && argc==4 ){
+    fi= fopen(argv[3], "rb");
+    if( !fi )
+      printf("\nInput file not found: %s\n", argv[3]),
+      exit(-1);
+    fseek(fo, 0x7000, SEEK_SET);
+    fread(mem, 1, 0x40, fo);
+    for ( i= 0; i<0x40; i++ )
+      if( mem[i]==0xff )
+        break;
+    mem[i]= i;
+    fseek(fo, 0x7000, SEEK_SET);
+    fwrite(mem, 1, 0x40, fo);
+    fread(mem, 1, 0x58, fi);
+    fseek(fo, 0x6000|i<<6, SEEK_SET);
+    k= mem[2]= atoi(argv[2]);
+    fwrite(mem+2,    1, 0x20, fo);
+    fwrite(mem+0x34, 1, 0x20, fo);
+    j= mem[3];
+    for ( i=0; i<j; i++ )
+      fseek(fo, (k<19?0xc000:0x300000)+k*0x4000, SEEK_SET),
+      k= (k+1)&0x3f,
+      fread(mem, 1, 0x4004, fi),
+      fwrite(mem, 1, 0x4000, fo);
+  }
+  else
+    printf("\nInvalid parameters\n"),
+    exit(-1);
+  printf("File `" OUTPUT_FILE "' is successfully updated.\n");
+}
diff --git a/sdk/src/tools/Makefile b/sdk/src/tools/Makefile
index 3f840d1..61fb11b 100644
--- a/sdk/src/tools/Makefile
+++ b/sdk/src/tools/Makefile
@@ -24,12 +24,14 @@ FCUT	:= fcut$(EXECEXT)
 FPAD	:= fpad$(EXECEXT)
 FPOKE	:= fpoke$(EXECEXT)
 GENROM	:= GenRom$(EXECEXT)
+ADDITEM	:= AddItem$(EXECEXT)
 
 TOOLS:=\
  $(FCUT) \
  $(FPAD) \
  $(FPOKE) \
- $(GENROM)
+ $(GENROM) \
+ $(ADDITEM)
 
 .PHONY: all
 all: $(TOOLS)
@@ -46,6 +48,9 @@ $(FPOKE): fpoke.c
 $(GENROM): GenRom.c
 	$(CC) $(CFLAGS) -o $@ $<
 
+$(ADDITEM): AddItem.c
+	$(CC) $(CFLAGS) -o $@ $<
+
 .PHONY: clean
 clean:
 	rm -f $(TOOLS)