diff --git a/cores/Spectrum/bootloader_hex.txt b/cores/Spectrum/bootloader_hex.txt
index fe28cab..11333ae 100644
--- a/cores/Spectrum/bootloader_hex.txt
+++ b/cores/Spectrum/bootloader_hex.txt
@@ -75,7 +75,7 @@ FE
 27
 EF
 0B
-80
+C0
 EF
 03
 01
diff --git a/firmware/firmware.asm b/firmware/firmware.asm
index 911b3ca..07dbccb 100644
--- a/firmware/firmware.asm
+++ b/firmware/firmware.asm
@@ -223,7 +223,8 @@ start   ld      bc, chrend-runbit
         ld      a, (outvid)
         scf
         rra
-        ld      (scnbak), a
+        or      $40
+        ld      (scnbak), a       ; lo pongo a 28Mhz
         out     (c), a
         im      1
         ld      de, fincad-1    ; descomprimo cadenas