diff --git a/utils/Makefile b/utils/Makefile
index a34fb94..7df917f 100644
--- a/utils/Makefile
+++ b/utils/Makefile
@@ -42,6 +42,7 @@ $(BUILD_DIR)/BACK16M: back16m.asm\
  esxdos.def\
  Print.inc\
  rdflsh.inc\
+ rst28.inc\
  | $(BUILD_DIR)
 	$(AS) $(AFLAGS) --raw=$@ $<
 
@@ -50,6 +51,7 @@ $(BUILD_DIR)/BACKZX2: back32m.asm\
  esxdos.def\
  Print.inc\
  rdflsh.inc\
+ rst28.inc\
  | $(BUILD_DIR)
 	echo ' define zxdos 1' >back32m.def
 	$(AS) $(AFLAGS) --raw=$@ $<
@@ -60,6 +62,7 @@ $(BUILD_DIR)/BACKZXD: back32m.asm\
  esxdos.def\
  Print.inc\
  rdflsh.inc\
+ rst28.inc\
  | $(BUILD_DIR)
 	echo ' define zxdos 0' >back32m.def
 	$(AS) $(AFLAGS) --raw=$@ $<
@@ -70,6 +73,7 @@ $(BUILD_DIR)/BACKUP: backup.asm\
  esxdos.def\
  Print.inc\
  rdflsh.inc\
+ rst28.inc\
  | $(BUILD_DIR)
 	$(AS) $(AFLAGS) --raw=$@ $<
 
@@ -78,6 +82,7 @@ $(BUILD_DIR)/CORCLEAN: corclean.asm\
  Print.inc\
  rdflsh.inc\
  wrflsh.inc\
+ rst28.inc\
  | $(BUILD_DIR)
 	$(AS) $(AFLAGS) --raw=$@ $<
 
@@ -87,6 +92,7 @@ $(BUILD_DIR)/COREBIOS: corebios.asm\
  Print.inc\
  rdflsh.inc\
  wrflsh.inc\
+ rst28.inc\
  | $(BUILD_DIR)
 	$(AS) $(AFLAGS) --raw=$@ $<
 
@@ -95,6 +101,7 @@ $(BUILD_DIR)/ROMSBACK: romsback.asm\
  esxdos.def\
  Print.inc\
  rdflsh.inc\
+ rst28.inc\
  | $(BUILD_DIR)
 	$(AS) $(AFLAGS) --raw=$@ $<
 
@@ -104,6 +111,7 @@ $(BUILD_DIR)/ROMSUPGR: romsupgr.asm\
  Print.inc\
  rdflsh.inc\
  wrflsh.inc\
+ rst28.inc\
  | $(BUILD_DIR)
 	$(AS) $(AFLAGS) --raw=$@ $<
 
@@ -112,6 +120,7 @@ $(BUILD_DIR)/UPGR16M: upgr16m.asm\
  esxdos.def\
  Print.inc\
  wrflsh.inc\
+ rst28.inc\
  | $(BUILD_DIR)
 	$(AS) $(AFLAGS) --raw=$@ $<
 
@@ -120,6 +129,7 @@ $(BUILD_DIR)/UPGRZX2: upgr32m.asm\
  esxdos.def\
  Print.inc\
  wrflsh.inc\
+ rst28.inc\
  | $(BUILD_DIR)
 	echo ' define zxdos 1' >upgr32m.def
 	$(AS) $(AFLAGS) --raw=$@ $<
@@ -130,6 +140,7 @@ $(BUILD_DIR)/UPGRZXD: upgr32m.asm\
  esxdos.def\
  Print.inc\
  wrflsh.inc\
+ rst28.inc\
  | $(BUILD_DIR)
 	echo ' define zxdos 0' >upgr32m.def
 	$(AS) $(AFLAGS) --raw=$@ $<
@@ -140,6 +151,7 @@ $(BUILD_DIR)/UPGRADE: upgrade.asm\
  esxdos.def\
  Print.inc\
  wrflsh.inc\
+ rst28.inc\
  | $(BUILD_DIR)
 	$(AS) $(AFLAGS) --raw=$@ $<
 
diff --git a/utils/back16m.asm b/utils/back16m.asm
index 0bb5114..931235f 100644
--- a/utils/back16m.asm
+++ b/utils/back16m.asm
@@ -120,12 +120,6 @@ WriteOK         ld      de, $0040
 
                 include Print.inc
                 include rdflsh.inc
-
-rst28           ld      bc, zxuno_port + $100
-                pop     hl
-                outi
-                ld      b, (zxuno_port >> 8)+2
-                outi
-                jp      (hl)
+                include rst28.inc
 
 FileName        dz      FLASH_FILE
diff --git a/utils/back32m.asm b/utils/back32m.asm
index 357b5db..89c9abb 100644
--- a/utils/back32m.asm
+++ b/utils/back32m.asm
@@ -154,12 +154,6 @@ WriteOK         ld      de, $0040
 
                 include Print.inc
                 include rdflsh.inc
-
-rst28           ld      bc, zxuno_port + $100
-                pop     hl
-                outi
-                ld      b, (zxuno_port >> 8)+2
-                outi
-                jp      (hl)
+                include rst28.inc
 
 FileName        dz      FLASH_FILE
diff --git a/utils/backup.asm b/utils/backup.asm
index 57957b4..66fad32 100644
--- a/utils/backup.asm
+++ b/utils/backup.asm
@@ -104,12 +104,6 @@ WriteOK         ld      de, $0040
 
                 include Print.inc
                 include rdflsh.inc
-
-rst28           ld      bc, zxuno_port + $100
-                pop     hl
-                outi
-                ld      b, (zxuno_port >> 8)+2
-                outi
-                jp      (hl)
+                include rst28.inc
 
 FileName        dz      FLASH_FILE
diff --git a/utils/corclean.asm b/utils/corclean.asm
index 27986e7..bea1553 100644
--- a/utils/corclean.asm
+++ b/utils/corclean.asm
@@ -75,12 +75,6 @@ normal          ld      a, 0
                 include Print.inc
                 include rdflsh.inc
                 include wrflsh.inc
-
-rst28           ld      bc, zxuno_port + $100
-                pop     hl
-                outi
-                ld      b, (zxuno_port >> 8)+2
-                outi
-                jp      (hl)
+                include rst28.inc
 
 ;FileName        dz      ROMS_FILE
diff --git a/utils/corebios.asm b/utils/corebios.asm
index 1a4f287..7279d3f 100644
--- a/utils/corebios.asm
+++ b/utils/corebios.asm
@@ -133,13 +133,7 @@ normal          ld      a, 0
                 include Print.inc
                 include rdflsh.inc
                 include wrflsh.inc
-
-rst28           ld      bc, zxuno_port + $100
-                pop     hl
-                outi
-                ld      b, (zxuno_port >> 8)+2
-                outi
-                jp      (hl)
+                include rst28.inc
 
 FileCore        dz      CORE_FILE
 FileBios        dz      BIOS_FILE
diff --git a/utils/romsback.asm b/utils/romsback.asm
index 948a5e6..96851f9 100644
--- a/utils/romsback.asm
+++ b/utils/romsback.asm
@@ -154,12 +154,6 @@ wrear0          wreg    flash_cs, 0     ; activamos spi, enviando un 0
 
                 include Print.inc
                 include rdflsh.inc
-
-rst28           ld      bc, zxuno_port + $100
-                pop     hl
-                outi
-                ld      b, (zxuno_port >> 8)+2
-                outi
-                jp      (hl)
+                include rst28.inc
 
 FileName        dz      ROMS_FILE
diff --git a/utils/romsupgr.asm b/utils/romsupgr.asm
index adcfc6e..299892b 100644
--- a/utils/romsupgr.asm
+++ b/utils/romsupgr.asm
@@ -182,12 +182,6 @@ wrear0          wreg    flash_cs, 0     ; activamos spi, enviando un 0
                 include Print.inc
                 include rdflsh.inc
                 include wrflsh.inc
-
-rst28           ld      bc, zxuno_port + $100
-                pop     hl
-                outi
-                ld      b, (zxuno_port >> 8)+2
-                outi
-                jp      (hl)
+                include rst28.inc
 
 FileName        dz      ROMS_FILE
diff --git a/utils/upgr16m.asm b/utils/upgr16m.asm
index 7f19de3..2628b42 100644
--- a/utils/upgr16m.asm
+++ b/utils/upgr16m.asm
@@ -126,12 +126,6 @@ ReadOK          ld      a, $40
 
                 include Print.inc
                 include wrflsh.inc
-
-rst28           ld      bc, zxuno_port + $100
-                pop     hl
-                outi
-                ld      b, (zxuno_port >> 8)+2
-                outi
-                jp      (hl)
+                include rst28.inc
 
 FileName        dz      FLASH_FILE
diff --git a/utils/upgr32m.asm b/utils/upgr32m.asm
index 865ae25..53c824f 100644
--- a/utils/upgr32m.asm
+++ b/utils/upgr32m.asm
@@ -159,12 +159,6 @@ ReadOK          ld      a, $40
 
                 include Print.inc
                 include wrflsh.inc
-
-rst28           ld      bc, zxuno_port + $100
-                pop     hl
-                outi
-                ld      b, (zxuno_port >> 8)+2
-                outi
-                jp      (hl)
+                include rst28.inc
 
 FileName        dz      FLASH_FILE
diff --git a/utils/upgrade.asm b/utils/upgrade.asm
index fcdd311..c9f4d4a 100644
--- a/utils/upgrade.asm
+++ b/utils/upgrade.asm
@@ -109,12 +109,6 @@ ReadOK          ld      a, $40
 
                 include Print.inc
                 include wrflsh.inc
-
-rst28           ld      bc, zxuno_port + $100
-                pop     hl
-                outi
-                ld      b, (zxuno_port >> 8)+2
-                outi
-                jp      (hl)
+                include rst28.inc
 
 FileName        dz      FLASH_FILE