diff --git a/source/genesis.c b/source/genesis.c
index 8fd6e9a..7621dfb 100644
--- a/source/genesis.c
+++ b/source/genesis.c
@@ -138,8 +138,8 @@ void gen_hardreset(void)
     m68k_memory_map[0].base = bios_rom;
   }
 
-  /* Reset CPU cycles */
-  mcycles_68k = mcycles_z80 = 0;
+  /* 68k & Z80 could restart anywhere in VDP frame (Bonkers, Eternal Champions, X-Men 2) */
+  mcycles_68k = mcycles_z80 = (uint32)((MCYCLES_PER_LINE * lines_per_frame) * ((double)rand() / (double)RAND_MAX));
 
   /* Z80 bus is released & Z80 is stopped */
   m68k_memory_map[0xa0].read8   = m68k_read_bus_8;
@@ -172,7 +172,7 @@ void gen_softreset(int state)
     if (config.lock_on == TYPE_AR)
       datel_reset(0);
 
-    /* 68k & Z80 could restart anywhere in VDP frame (fixes Eternal Champions, X-Men 2) */
+    /* 68k & Z80 could restart anywhere in VDP frame (Bonkers, Eternal Champions, X-Men 2) */
     mcycles_68k = mcycles_z80 = (uint32)((MCYCLES_PER_LINE * lines_per_frame) * ((double)rand() / (double)RAND_MAX));
 
     /* Reset 68k, Z80 & YM2612 */
diff --git a/source/mem68k.c b/source/mem68k.c
index fa3dab9..720883f 100644
--- a/source/mem68k.c
+++ b/source/mem68k.c
@@ -483,8 +483,13 @@ void ctrl_io_write_word(unsigned int address, unsigned int data)
 
     case 0x40:  /* TMSS */
     {
-      gen_tmss_w(address & 3, data);
-      break;
+      if (config.tmss & 1)
+      {
+        gen_tmss_w(address & 3, data);
+        return;
+      }
+      m68k_unused_16_w(address, data);
+      return;
     }
 
     case 0x50:  /* SVP REGISTERS */