fixed cart mapper, code cleanup

source/cart_hw/cart_hw.c

@@ -3,7 +3,7 @@
  *  Genesis Plus 1.2a
  *  Cartridge Hardware support
  *
- *  code by Eke-Eke, GC/Wii port
+ *  Copyright (C) Eke-Eke, GC/Wii port
  *
  *  Most cartridge protections documented by Haze
  *  (http://haze.mameworld.info/)
@@ -112,7 +112,7 @@ T_CART_ENTRY rom_database[CART_CNT] =
 
 
 /* previous inputs */
-static int old_system[2] = {-1,-1};
+int old_system[2] = {-1,-1};
 
 /* temporary memory chunk */
 uint8 mem_chunk[0x10000];
@@ -341,9 +341,6 @@ void cart_hw_init()
 	***********************************************/
 	memset(&cart_hw, 0, sizeof(cart_hw));
 
-	/* default write handler for !TIME signal */
-	cart_hw.time_w = default_time_w;
-
   /* search for game into database */
 	for (i=0; i < CART_CNT + 1; i++)
 	{
@@ -405,11 +402,15 @@ void cart_hw_init()
     /* assume SSF2 mapper */
     cart_hw.bankshift = 1;
   }
+
+	/* default write handler for !TIME signal */
+	if (!cart_hw.time_w) cart_hw.time_w = default_time_w;
 }
 
 /************************************************************
 					MAPPER handlers 
 *************************************************************/
+
 /* 
 	"official" ROM/RAM switch
 */
@@ -492,7 +493,7 @@ void special_mapper_w(uint32 address, uint32 data)
 	Realtec ROM Bankswitch (Earth Defend, Balloon Boy & Funny World, Whac-A-Critter)
 */
 void realtec_mapper_w(uint32 address, uint32 data)
-	{
+{
   int i;
 	uint32 base;
 
@@ -551,7 +552,7 @@ void seganet_mapper_w(uint32 address, uint32 data)
     else
     {
       /* ROM Write enabled */
-      for (i=0; i<0x40; i++);
+      for (i=0; i<0x40; i++)
       {
         m68k_memory_map[i].write8   = NULL;
         m68k_memory_map[i].write16  = NULL;
@@ -571,7 +572,7 @@ uint32 radica_mapper_r(uint32 address)
   
 	/* 64 x 64k banks */
   for (i = 0; i < 64; i++)
-{
+  {
     m68k_memory_map[i].base = &cart_rom[((address++)& 0x3f)<< 16];
 	}
 	return 0xff;

source/cart_hw/cart_hw.h

@@ -2,7 +2,7 @@
  *  Genesis Plus 1.2a
  *  Cartridge Hardware support
  *
- *  code by Eke-Eke, GC/Wii port
+ *  Copyright (C) Eke-Eke, GC/Wii port
  *
  *  Lots of protection mechanism have been discovered by Haze
  *  (http://haze.mameworld.info/)

source/cart_hw/eeprom.c

@@ -2,7 +2,7 @@
  *  Genesis Plus 1.2a
  *  Serial EEPROM support
  *
- *  code by Eke-Eke, GC/Wii port
+ *  Copyright (C) Eke-Eke, GC/Wii port
  *
  *  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

source/cart_hw/eeprom.h

@@ -2,7 +2,7 @@
  *  Genesis Plus 1.2a
  *  Serial EEPROM support
  *
- *  code by Eke-Eke, GC/Wii port
+ *  Copyright (C) Eke-Eke, GC/Wii port
  *
  *  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

source/mem68k.c

@@ -28,22 +28,6 @@ uint32 m68k_read_bus_8(uint32 address)
 {
 #ifdef LOGERROR
   error("Unused read8 %08X (%08X)\n", address, m68k_get_reg (NULL, M68K_REG_PC));
-		error("D0 = %x \n", m68k_get_reg (NULL, M68K_REG_D0));
-		error("D1 = %x \n", m68k_get_reg (NULL, M68K_REG_D1));
-		error("D2 = %x \n", m68k_get_reg (NULL, M68K_REG_D2));
-		error("D3 = %x \n", m68k_get_reg (NULL, M68K_REG_D3));
-		error("D4 = %x \n", m68k_get_reg (NULL, M68K_REG_D4));
-		error("D5 = %x \n", m68k_get_reg (NULL, M68K_REG_D5));
-		error("D6 = %x \n", m68k_get_reg (NULL, M68K_REG_D6));
-		error("D7 = %x \n", m68k_get_reg (NULL, M68K_REG_D7));
-		error("A0 = %x \n", m68k_get_reg (NULL, M68K_REG_A0));
-		error("A1 = %x \n", m68k_get_reg (NULL, M68K_REG_A1));
-		error("A2 = %x \n", m68k_get_reg (NULL, M68K_REG_A2));
-		error("A3 = %x \n", m68k_get_reg (NULL, M68K_REG_A3));
-		error("A4 = %x \n", m68k_get_reg (NULL, M68K_REG_A4));
-		error("A5 = %x \n", m68k_get_reg (NULL, M68K_REG_A5));
-		error("A6 = %x \n", m68k_get_reg (NULL, M68K_REG_A6));
-		error("A7 = %x \n", m68k_get_reg (NULL, M68K_REG_A7));
 #endif
   return m68k_read_pcrelative_8(REG_PC | (address&1));
 
@@ -53,22 +37,6 @@ uint32 m68k_read_bus_16(uint32 address)
 {
 #ifdef LOGERROR
   error("Unused read16 %08X (%08X)\n", address, m68k_get_reg (NULL, M68K_REG_PC));
-		error("D0 = %x \n", m68k_get_reg (NULL, M68K_REG_D0));
-		error("D1 = %x \n", m68k_get_reg (NULL, M68K_REG_D1));
-		error("D2 = %x \n", m68k_get_reg (NULL, M68K_REG_D2));
-		error("D3 = %x \n", m68k_get_reg (NULL, M68K_REG_D3));
-		error("D4 = %x \n", m68k_get_reg (NULL, M68K_REG_D4));
-		error("D5 = %x \n", m68k_get_reg (NULL, M68K_REG_D5));
-		error("D6 = %x \n", m68k_get_reg (NULL, M68K_REG_D6));
-		error("D7 = %x \n", m68k_get_reg (NULL, M68K_REG_D7));
-		error("A0 = %x \n", m68k_get_reg (NULL, M68K_REG_A0));
-		error("A1 = %x \n", m68k_get_reg (NULL, M68K_REG_A1));
-		error("A2 = %x \n", m68k_get_reg (NULL, M68K_REG_A2));
-		error("A3 = %x \n", m68k_get_reg (NULL, M68K_REG_A3));
-		error("A4 = %x \n", m68k_get_reg (NULL, M68K_REG_A4));
-		error("A5 = %x \n", m68k_get_reg (NULL, M68K_REG_A5));
-		error("A6 = %x \n", m68k_get_reg (NULL, M68K_REG_A6));
-		error("A7 = %x \n", m68k_get_reg (NULL, M68K_REG_A7));
 #endif
   return m68k_read_pcrelative_16(REG_PC);
 }
@@ -143,43 +111,35 @@ static int pico_page[7] = {0x00,0x01,0x03,0x07,0x0F,0x1F,0x3F};
 
 uint32 eeprom_read_byte(uint32 address)
 {
-  if (address == eeprom.type.sda_out_adr)
+  if (address == eeprom.type.sda_out_adr) return eeprom_read(address, 0);
-    return eeprom_read(address, 0);
+  else return READ_BYTE(cart_rom, address);
-  else
-    return READ_BYTE(cart_rom, address);
 }
 
 uint32 eeprom_read_word(uint32 address)
 {
-  if (address == (eeprom.type.sda_out_adr & 0xfffffe))
+  if (address == (eeprom.type.sda_out_adr & 0xfffffe)) return eeprom_read(address, 1);
-    return eeprom_read(address, 1);
+  else return *(uint16 *)(cart_rom + address);
-  else
-    return *(uint16 *)(cart_rom + address);
 }
 
 void eeprom_write_byte(uint32 address, uint32 data)
 {
-  if ((address == eeprom.type.sda_in_adr) ||
+  if ((address == eeprom.type.sda_in_adr) || (address == eeprom.type.scl_adr))
-      (address == eeprom.type.scl_adr))
     eeprom_write(address, data, 0);
-  else
+  else m68k_unused_8_w(address, data);
-    m68k_unused_8_w(address, data);
 }
 
 void eeprom_write_word(uint32 address, uint32 data)
 {
-  if ((address == (eeprom.type.sda_in_adr&0xfffffe)) ||
+  if ((address == (eeprom.type.sda_in_adr&0xfffffe)) || (address == (eeprom.type.scl_adr&0xfffffe)))
-      (address == (eeprom.type.scl_adr&0xfffffe)))
     eeprom_write(address, data, 1);
-  else
+  else m68k_unused_16_w (address, data);
-    m68k_unused_16_w (address, data);
 }
 
 
 /******* Z80  *************************************************/
 
 uint32 z80_read_byte(uint32 address)
-      {
+{
   if (zbusack) return m68k_read_bus_8(address);
           
   switch ((address >> 13) & 3)
@@ -188,15 +148,13 @@ uint32 z80_read_byte(uint32 address)
       return fm_read(0, address & 3);
 
     case 3:   /* MISC */
-      if ((address & 0xff00) == 0x7f00)
+      if ((address & 0xff00) == 0x7f00) return m68k_lockup_r_8(address); /* VDP */
-        return m68k_lockup_r_8(address); /* VDP */
+      else return (m68k_read_bus_8(address) | 0xff);
-      else
-        return (m68k_read_bus_8(address) | 0xff);
 
     default: /* ZRAM */
       return zram[address & 0x1fff];
   }
-			}
+}
             
 uint32 z80_read_word(uint32 address)
 {
@@ -211,10 +169,8 @@ uint32 z80_read_word(uint32 address)
     }
 
     case 3:   /* MISC */
-      if ((address & 0xff00) == 0x7f00)
+      if ((address & 0xff00) == 0x7f00) return m68k_lockup_r_16(address); /* VDP */
-        return m68k_lockup_r_16(address); /* VDP */
+      else return (m68k_read_bus_16(address) | 0xffff);
-      else
-        return (m68k_read_bus_16(address) | 0xffff);
 
     default:  /* ZRAM */
     {
@@ -222,7 +178,7 @@ uint32 z80_read_word(uint32 address)
       return (temp << 8 | temp);
     }
   }
-			}
+}
       
 void z80_write_byte(uint32 address, uint32 data)
 {
@@ -259,10 +215,10 @@ void z80_write_byte(uint32 address, uint32 data)
       count_m68k++; /* Z80 bus latency (Pacman 2: New Adventures) */
       return;
   }
-				}
+}
 
 void z80_write_word(uint32 address, uint32 data)
-    {
+{
   /* Z80 still hold the bus ? */
   if (zbusack)
   {
@@ -302,27 +258,20 @@ void z80_write_word(uint32 address, uint32 data)
 /******* I/O & CTRL ******************************************/
           
 uint32 ctrl_io_read_byte(uint32 address)
-				{
+{
-  /* I/O & CONTROL REGISTERS */
   switch ((address >> 8) & 0xff)
   {
     case 0x00:  /* I/O chip */
-        if (address & 0xe0)
+      if (address & 0xe0) return m68k_read_bus_8(address);
-          return m68k_read_bus_8(address);
+      else return (io_read((address >> 1) & 0x0f));
-        else
-          return (io_read((address >> 1) & 0x0f));
 
     case 0x11:  /* BUSACK */
-        if (address & 1)
+      if (address & 1) return m68k_read_bus_8(address);
-          return m68k_read_bus_8(address);
+      else return ((m68k_read_pcrelative_8(REG_PC) & 0xfe) | zbusack);
-        else
-          return ((m68k_read_pcrelative_8(REG_PC) & 0xfe) | zbusack);
 
     case 0x30:  /* TIME */
-        if (cart_hw.time_r)
+      if (cart_hw.time_r) return cart_hw.time_r(address);
-          return cart_hw.time_r(address);
+      else return m68k_read_bus_8(address);
-        else
-          return m68k_read_bus_8(address);
 
     case 0x10:  /* MEMORY MODE */
     case 0x12:  /* RESET */
@@ -336,16 +285,15 @@ uint32 ctrl_io_read_byte(uint32 address)
     default:  /* Invalid address */
       return m68k_lockup_r_8(address);
   }
-			}
+}
 
 uint32 ctrl_io_read_word(uint32 address)
-			{
+{
   switch ((address >> 8) & 0xff)
   {
     case 0x00:  /* I/O chip */
     {
-      if (address & 0xe0)
+      if (address & 0xe0) return m68k_read_bus_16(address);
-        return m68k_read_bus_16(address);
       int temp = io_read((address >> 1) & 0x0f);
       return (temp << 8 | temp);
     }
@@ -353,33 +301,21 @@ uint32 ctrl_io_read_word(uint32 address)
     case 0x11:  /* BUSACK */
       return ((m68k_read_pcrelative_16(REG_PC) & 0xfeff) | (zbusack << 8));
 
+    case 0x30:  /* TIME */
+      if (cart_hw.time_r) return cart_hw.time_r(address);
+      else return m68k_read_bus_16(address);
+
     case 0x50:  /* SVP */
       if (svp)
       {
-              switch (address & 0xff)
+        if ((address & 0xfd) == 0) return svp->ssp1601.gr[SSP_XST].h;
-              {
+        else if ((address & 0xff) == 4)
-                case 0:
-                case 2:
-                  return svp->ssp1601.gr[SSP_XST].h;
-
-                case 4:
         {
           uint32 temp = svp->ssp1601.gr[SSP_PM0].h;
           svp->ssp1601.gr[SSP_PM0].h &= ~1;
           return temp;
         }
-
-              default:
-                return m68k_read_bus_16(address);
       }
-						}
-      else 
-            return m68k_read_bus_16(address);
-
-					case 0x30:	/* TIME */
-      if (cart_hw.time_r)
-        return cart_hw.time_r(address);
-      else
       return m68k_read_bus_16(address);
 
     case 0x10:  /* MEMORY MODE */
@@ -393,38 +329,29 @@ uint32 ctrl_io_read_word(uint32 address)
     default:  /* Invalid address */
       return m68k_lockup_r_16(address);
   }
-			}
+}
 
 void ctrl_io_write_byte(uint32 address, uint32 data)
-			{  			
+{        
   switch ((address >> 8) & 0xff)
   {
     case 0x00:  /* I/O chip */
-      if ((address & 0xe1) == 0x01)
+      if ((address & 0xe1) == 0x01) io_write((address >> 1) & 0x0f, data); /* get /LWR only */
-        io_write((address >> 1) & 0x0f, data); /* get /LWR only */
+      else m68k_unused_8_w(address, data);
-      else
-        m68k_unused_8_w(address, data);
       return;
 
     case 0x11:  /* BUSREQ */
-      if (address & 1)
+      if (address & 1) m68k_unused_8_w(address, data);
-        m68k_unused_8_w(address, data);
+      else gen_busreq_w(data & 1);
-      else
-        gen_busreq_w(data & 1);
       return;
 
     case 0x12:  /* RESET */
-      if (address & 1)
+      if (address & 1) m68k_unused_8_w(address, data);
-        m68k_unused_8_w(address, data);
+      else gen_reset_w(data & 1);
-      else
-        gen_reset_w(data & 1);
       return;
 
     case 0x30:  /* TIME */
-      if (cart_hw.time_w)
       cart_hw.time_w(address, data);
-      else
-        m68k_unused_8_w(address, data);
       return;
 
     case 0x41:  /* BOOTROM */
@@ -455,17 +382,15 @@ void ctrl_io_write_byte(uint32 address, uint32 data)
       m68k_lockup_w_8(address, data);
       return;
   }
-			}
+}
 
 void ctrl_io_write_word(uint32 address, uint32 data)
-	    {				
+{        
   switch ((address >> 8) & 0xff)
   {
     case 0x00:  /* I/O chip */
-      if (address & 0xe0)
+      if (address & 0xe0) m68k_unused_16_w (address, data);
-        m68k_unused_16_w (address, data);
+      else io_write ((address >> 1) & 0x0f, data & 0xff);
-      else
-        io_write ((address >> 1) & 0x0f, data & 0xff);
       return;
         
     case 0x11:  /* BUSREQ */
@@ -479,8 +404,7 @@ void ctrl_io_write_word(uint32 address, uint32 data)
     case 0x50:  /* SVP REGISTERS */
       if (svp)
       {
-        if (address & 0xfd)
+        if (address & 0xfd) m68k_unused_16_w(address, data);
-          m68k_unused_16_w(address, data);
         else
         {
           /* just guessing here (Notaz) */
@@ -489,18 +413,12 @@ void ctrl_io_write_word(uint32 address, uint32 data)
           svp->ssp1601.emu_status &= ~SSP_WAIT_PM0;
         }
       }
-      else
+      else m68k_unused_16_w (address, data);
-        m68k_unused_16_w (address, data);
       return;
 
     case 0x30:  /* TIME */
-						if (cart_hw.time_w)
-						{
       cart_hw.time_w(address & 0xfe, data >> 8);
       cart_hw.time_w(address, data & 0xff);
-						}
-      else
-        m68k_unused_16_w (address, data);
       return;
           
     case 0x41:  /* BOOTROM */
@@ -527,7 +445,7 @@ void ctrl_io_write_word(uint32 address, uint32 data)
       m68k_lockup_w_16 (address, data);
       return;
   }
-			}
+}
 
 
 /******* VDP *************************************************/
@@ -623,7 +541,7 @@ void vdp_write_byte(uint32 address, uint32 data)
 }
 
 void vdp_write_word(uint32 address, uint32 data)
-    {
+{
   switch (address & 0xfc)
   {
     case 0x00:  /* DATA */
@@ -651,7 +569,7 @@ void vdp_write_word(uint32 address, uint32 data)
       m68k_lockup_w_16 (address, data);
       return;
   }
-    }
+}
 
 
 /******* PICO ************************************************/

source/membnk.c

@@ -60,7 +60,6 @@ void zbank_lockup_w(uint32 address, uint32 data)
 }
 
 /* I/O & Control registers */
-
 uint32 zbank_read_ctrl_io(uint32 address)
 {
   switch ((address >> 8) & 0xff)
@@ -89,10 +88,10 @@ uint32 zbank_read_ctrl_io(uint32 address)
     default:	/* Invalid address */
       return zbank_lockup_r(address);
   }
-      }
+}
 
 void zbank_write_ctrl_io(uint32 address, uint32 data)
-			{  			
+{  			
   switch ((address >> 8) & 0xff)
   {
     case 0x00:	/* I/O chip */
@@ -143,13 +142,12 @@ void zbank_write_ctrl_io(uint32 address, uint32 data)
       zbank_lockup_w(address, data);
       return;
   }
-			}
+}
 
 
-    /* VDP */
+/* VDP */
-			
 uint32 zbank_read_vdp(uint32 address)
-				{
+{
   switch (address & 0xfd)
   {
     case 0x00:		/* DATA */
@@ -181,7 +179,7 @@ uint32 zbank_read_vdp(uint32 address)
     default:		/* Invalid address */
       return zbank_lockup_r(address);
   }
-			  }
+}
 
 void zbank_write_vdp(uint32 address, uint32 data)
 {

source/state.c

@@ -2,7 +2,7 @@
  *  Genesis Plus 1.2a
  *  FreezeState support
  *
- *  coded by Eke-Eke, GC/Wii port
+ *  Copyright (C) Eke-Eke, GC/Wii port
  *
  *  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

source/state.h

@@ -2,7 +2,7 @@
  *  Genesis Plus 1.2a
  *  FreezeState support
  *
- *  coded by Eke-Eke, GC/Wii port
+ *  Copyright (C) Eke-Eke, GC/Wii port
  *
  *  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

source/system.c

@@ -23,8 +23,6 @@
 
 #include "shared.h"
 
-#define CLOCK_NTSC 53693175
-#define CLOCK_PAL  53203424
 #define SND_SIZE (snd.buffer_size * sizeof(int16))
 
 /* Global variables */
@@ -32,7 +30,6 @@ t_bitmap bitmap;
 t_snd snd;
 uint8  vdp_rate;
 uint16 lines_per_frame;
-double Master_Clock;
 uint32 aim_m68k;
 uint32 count_m68k;
 uint32 line_m68k;
@@ -55,7 +52,6 @@ void system_init (void)
 	/* PAL/NTSC timings */
 	vdp_rate        = vdp_pal ? 50 : 60;
 	lines_per_frame = vdp_pal ? 313 : 262;
-	Master_Clock	  = vdp_pal ? (double)CLOCK_PAL : (double)CLOCK_NTSC;
 	
 	gen_init ();
 	vdp_init ();
@@ -139,27 +135,29 @@ int system_frame (int do_skip)
 	}
   odd_frame ^= 1;
 
-  /* update VDP status  */
+  /* clear VBLANK and DMA flags */
-  status &= 0xFFF5;                               // clear VBLANK and DMA flags
+  status &= 0xFFF5;
-  if (odd_frame && interlaced) status |= 0x0010;  // even/odd field flag (interlaced modes only)
+  
+  /* even/odd field flag (interlaced modes only) */
+  if (odd_frame && interlaced) status |= 0x0010;
   else status &= 0xFFEF;
 
-	/* Reload H Counter */
+	/* reload HCounter */
 	int h_counter = reg[10];
 
   /* parse sprites for line 0 (done on last line) */
 	parse_satb (0x80);
 
-	/* Line processing */
+	/* process frame */
 	for (line = 0; line < lines_per_frame; line ++)
 	{
-    /* Update VCounter */
+    /* update VCounter */
 		v_counter = line;
 
-		/* 6-Buttons or Menacer update */
+		/* update 6-Buttons or Menacer */
 		input_update();
 
- 		/* Update CPU cycle counters */
+ 		/* update CPU cycle counters */
     hint_m68k = count_m68k;
     line_m68k = aim_m68k;
 		line_z80  = aim_z80;
@@ -176,9 +174,10 @@ int system_frame (int do_skip)
       gen_reset(0);
     }
 
-    /* Horizontal Interrupt */
+    /* active display */
     if (line <= vdp_height)
 		{
+			/* H Interrupt */
       if(--h_counter < 0)
 			{
 				h_counter = reg[10];
@@ -198,13 +197,13 @@ int system_frame (int do_skip)
       /* update DMA timings */
       if (dma_length) dma_update();
 
-		/* Vertical Retrace */
+		  /* vertical retrace */
       if (line == vdp_height)
 		  {
         /* render overscan */
         if ((line < end_line) && (!do_skip)) render_line(line, 1);
 
-      /* update inputs */
+        /* update inputs (doing this here fix Warriors of Eternal Sun) */
         update_input();
 
         /* set VBLANK flag */
@@ -223,10 +222,12 @@ int system_frame (int do_skip)
         }
         else count_z80 = line_z80 + 39;
 
-			/* Vertical Interrupt */
+			  /* V Interrupt */
         status |= 0x80;
         vint_pending = 1;
-        if (reg[1] & 0x20) irq_status = (irq_status & 0xff) | 0x2416; // 36 cycles latency after VINT occurence flag (Ex-Mutants, Tyrant)
+
+        /* 36 cycles latency after VINT occurence flag (Ex-Mutants, Tyrant) */
+        if (reg[1] & 0x20) irq_status = (irq_status & 0xff) | 0x2416; 
       }
       else if (!do_skip) 
       {
@@ -241,10 +242,7 @@ int system_frame (int do_skip)
       if (dma_length) dma_update();
 
       /* render overscan */
-      if ((line < end_line) || (line >= start_line))
+      if ((!do_skip) && ((line < end_line) || (line >= start_line))) render_line(line, 1);
-    {
-        if (!do_skip) render_line(line, 1);
-      }
 
       /* clear any pending Z80 interrupt */
       if (zirq)
@@ -254,7 +252,7 @@ int system_frame (int do_skip)
       }
     }
 
-		/* Process line */
+		/* process line */
 		m68k_run(aim_m68k);
 		if (zreset == 1 && zbusreq == 0)
     {

source/vdp.c

@@ -76,7 +76,6 @@ uint32 fifo_lastwrite;		        /* last VDP write cycle */
 uint8 fifo_latency;			          /* VDP write cycles latency */
 uint8 vdp_pal	= 0;		            /* 1: PAL , 0: NTSC (default) */
 
-double vdp_timings[4][4];
 
 /* Tables that define the playfield layout */
 static const uint8 shift_table[] = { 6, 7, 0, 8 };
@@ -88,6 +87,7 @@ static uint16 sat_base_mask;	/* Base bits of SAT */
 static uint16 sat_addr_mask;	    /* Index bits of SAT */
 static uint32 dma_endCycles;      /* 68k cycles to DMA end */
 static uint8 dma_type;            /* Type of DMA */
+static double vdp_timings[4][4];  /* DMA timings */
 
 static inline void vdp_reg_w(unsigned int r, unsigned int d);
 
@@ -159,6 +159,7 @@ void vdp_reset(void)
 	pending = 0;
 
 	status = 0x200; /* fifo empty */
+  status |= vdp_pal;
 
 	ntab = 0;
 	ntbb = 0;
@@ -365,9 +366,10 @@ static inline void dma_vbus (void)
 	dma_length = length;
 	dma_update();
 
-  switch (source >> 21)
+  /* DMA source */
+  if ((source >> 17) == 0x50)
   {
-    case 5:
+    /* Z80 & I/O area */
     do
     {
       /* Return $FFFF only when the Z80 isn't hogging the Z-bus.
@@ -391,13 +393,10 @@ static inline void dma_vbus (void)
       data_write (temp);
     }
     while (--length);
-      break;
+  }
-
+  else
-    case 0:
+  {
-    case 1:
+    /* ROM & RAM */
-      if (svp) source = source - 2;
-
-    default:
     do
     {
       temp = *(uint16 *)(m68k_memory_map[source>>16].base + (source & 0xffff));
@@ -406,7 +405,6 @@ static inline void dma_vbus (void)
       data_write (temp);
     }
     while (--length);
-      break;
   }
 
 	/* update length & source address registers */
@@ -442,7 +440,6 @@ static inline void dma_fill(unsigned int data)
 		{
 			/* update internal SAT (fix Battletech) */
 			WRITE_BYTE(sat, (addr & sat_addr_mask)^1, data);
-
 			WRITE_BYTE(vram, addr^1, data);
 			MARK_BG_DIRTY (addr);
 			addr += reg[15];
@@ -618,38 +615,25 @@ static inline void vdp_reg_w(unsigned int r, unsigned int d)
   switch(r)
   {
     case 0x00: /* CTRL #1 */
-			/* Check if HINT has been enabled or disabled */
       if (hint_pending && ((d&0x10) != (reg[0]&0x10)))
       {
+        /* update IRQ status */
         irq_status &= 0x20;
         irq_status |= 0x10;
-        if (vint_pending && (reg[1] & 0x20))
+        if (vint_pending && (reg[1] & 0x20)) irq_status |= 6;
-        {
+        else if (d & 0x10) irq_status |= 4;
-          irq_status |= 6;
-        }
-        else if (d & 0x10)
-        {
-          irq_status |= 4;
-        }
       }
       break;
 
     case 0x01: /* CTRL #2 */
-			/* Check if VINT has been enabled or disabled */
       if (vint_pending && ((d&0x20) != (reg[1]&0x20)))
       {
+        /* update IRQ status */
         irq_status &= 0x20;
         irq_status |= 0x110;
-        if (d & 0x20)
+        if (d & 0x20) irq_status |= 6;
-        {
+        else if (hint_pending && (reg[0] & 0x10)) irq_status |= 4;
-          irq_status |= 6;
       }
-        else if (hint_pending && (reg[0] & 0x10))
-        {
-          irq_status |= 4;
-        }
-      }
-
 
       /* Check if the viewport height has actually been changed */
       if((reg[1] & 8) != (d & 8))
@@ -805,9 +789,11 @@ unsigned int vdp_ctrl_r(void)
 
 	/* update DMA Busy flag */
 	if ((status & 2) && !dma_length && (count_m68k >= dma_endCycles))
+  {
     status &= 0xFFFD;
+  }
 
-	unsigned int temp = status | vdp_pal;
+	unsigned int temp = status;
 
 	/* display OFF: VBLANK flag is set */
 	if (!(reg[1] & 0x40)) temp |= 0x8; 
@@ -917,6 +903,7 @@ void vdp_test_w(unsigned int value)
 int vdp_int_ack_callback(int int_level)
 {
 
+  /* VINT triggered ? */
   if (irq_status&0x20)
 	{
 		vint_pending = 0;
@@ -927,15 +914,10 @@ int vdp_int_ack_callback(int int_level)
     hint_pending = 0;
   }
 
+  /* update IRQ status */
   irq_status = 0x10;
-  if (vint_pending && (reg[1] & 0x20))
+  if (vint_pending && (reg[1] & 0x20)) irq_status |= 6;
-  {
+  else if (hint_pending && (reg[0] & 0x10)) irq_status |= 4;
-    irq_status |= 6;
-  }
-  else if (hint_pending && (reg[0] & 0x10))
-  {
-    irq_status |= 4;
-  }
 
   return M68K_INT_ACK_AUTOVECTOR;
 }

source/vdp.h

@@ -63,7 +63,6 @@ extern int32 fifo_write_cnt;
 extern uint32 fifo_lastwrite;
 extern uint8 fifo_latency;
 extern uint8 vdp_pal;
-extern double vdp_timings[4][4];
 
 extern uint8 *vctab;
 extern uint8 *hctab;