diff --git a/main.cpp b/main.cpp
index 671e923..96d3ea3 100644
--- a/main.cpp
+++ b/main.cpp
@@ -28,6 +28,8 @@ int main(int argc, char *argv[])
 
     zx_tape::load("manic.tap");
 
+    if (argc==3) { z80debug::loadngo(argv[1], argv[2]); }
+
     bool should_exit = false;
     SDL_Event e;
 
@@ -86,12 +88,10 @@ int main(int argc, char *argv[])
                 z80debug::stop();
                 zxscreen::redraw();
             } else {
-                //if (z80::getPC()==0x05C8) zx_tape::go_berserk();
+                if (z80::getPC()==0x05C8) zx_tape::go_berserk();
                 uint8_t dt = z80::step();
                 zx_tape::update(dt);
-                //if (!zx_tape::berserk()) {
-                    zx_ula::sound_update(dt);
-                //}
+                zx_ula::sound_update(dt);
                 zxscreen::refresh(dt);
             }
         }
diff --git a/test.asm b/test.asm
new file mode 100644
index 0000000..c4b8160
--- /dev/null
+++ b/test.asm
@@ -0,0 +1,27 @@
+                .org $8000
+
+                ei
+START:
+                ld a, 2
+                out ($fe), a
+                ld b, 255
+                ld de, TILES
+                ld hl, $4000
+LOOP:
+                ld a, (de)
+                ld (hl), a
+                inc e
+                inc h
+                djnz LOOP
+                ld a, (de)
+                ld hl, $5800
+                ld (hl), a
+
+                ld a, 0
+                out ($fe), a
+
+                halt
+                jr START
+
+TILES:          db $81, $42, $24, $18, $18, $24, $42, $81, $4d
+
diff --git a/z80.cpp b/z80.cpp
index f2b59aa..f47b291 100644
--- a/z80.cpp
+++ b/z80.cpp
@@ -684,7 +684,7 @@ namespace z80
         if (exit_from_halt) {
             exit_from_halt = false;
         } else {
-            printf("HALT\n");
+            //printf("HALT\n");
             rPC--;
         }
     }
@@ -2697,4 +2697,5 @@ namespace z80
 
     uint16_t getPC() { return rPC; }
 
+    void setPC(const uint16_t addr) { rPC = addr; }
 }
\ No newline at end of file
diff --git a/z80.h b/z80.h
index d618c1f..8240d2c 100644
--- a/z80.h
+++ b/z80.h
@@ -21,4 +21,6 @@ namespace z80
     uint16_t getIY();
     uint16_t getSP();
     uint16_t getPC();
+
+    void setPC(const uint16_t addr);
 }
\ No newline at end of file
diff --git a/z80debug.cpp b/z80debug.cpp
index e79413c..39955be 100644
--- a/z80debug.cpp
+++ b/z80debug.cpp
@@ -74,7 +74,7 @@ namespace z80debug
 
     void show()
     {
-        is_debugging = true;
+        is_debugging = false;
         if (win) return;
         win = SDL_CreateWindow("Z80 Debugger", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, 71*CHR_W, 34*CHR_H, SDL_WINDOW_RESIZABLE);
         ren = SDL_CreateRenderer(win, -1, 0);
@@ -421,6 +421,14 @@ namespace z80debug
             int address = getnum(cmd);
             if (address<0 || address>65536) { strcpy(console_error, "Illegal memory address"); return; }
             mem_viewer_pos = address;
+        } else if (strcmp(cmd, "l")==0 || strcmp(cmd, "load")==0) {
+            getcmd();
+            char filename[256];
+            strcpy(filename, cmd);
+            getcmd();
+            char address[256];
+            strcpy(address, cmd);
+            loadngo(filename, address);
         }  
     }
 
@@ -441,4 +449,20 @@ namespace z80debug
     {
         mem_modified[addr] = true;
     }
+
+    void loadngo(const char* filename, const char* addr)
+    {
+        int address = getnum(addr);
+        if (address<0 || address>65536) { strcpy(console_error, "Illegal offset"); return; }
+
+        FILE *f = fopen(filename, "rb");
+        fseek(f, 0, SEEK_END);
+        int size = ftell(f);
+        fseek(f, 0, SEEK_SET);
+        uint8_t *memory = z80::getMem();
+        fread(memory+address, size, 1, f);
+        fclose(f);
+        z80::setPC(address);
+        is_debugging = false;
+    }
 }
\ No newline at end of file
diff --git a/z80debug.h b/z80debug.h
index 32210be..15eeec9 100644
--- a/z80debug.h
+++ b/z80debug.h
@@ -17,4 +17,6 @@ namespace z80debug
 
     const bool isbreak(const uint16_t address, const uint8_t type=1);
     uint32_t next();
+
+    void loadngo(const char* filename, const char* addr);
 }
\ No newline at end of file
diff --git a/zx_screen.cpp b/zx_screen.cpp
index a0e5cfb..168de53 100644
--- a/zx_screen.cpp
+++ b/zx_screen.cpp
@@ -2,6 +2,7 @@
 #include "z80.h"
 #include "zx_ula.h"
 #include <SDL2/SDL.h>
+#include "zx_tape.h"
 
 namespace zxscreen
 {
@@ -143,6 +144,8 @@ namespace zxscreen
 
     void redraw()
     {
+        if (zx_tape::berserk()) return;
+
         Uint32* pixels;
         int pitch;
         SDL_LockTexture(tex, NULL, (void**)&pixels, &pitch);