diff --git a/src/mame/drivers/ddragon.c b/src/mame/drivers/ddragon.c
index 575d5b3038f..3e9b62bb6da 100644
--- a/src/mame/drivers/ddragon.c
+++ b/src/mame/drivers/ddragon.c
@@ -81,7 +81,8 @@ Dip locations verified with manual for ddragon & ddragon2
 
 #define MAIN_CLOCK		XTAL_12MHz
 #define SOUND_CLOCK		XTAL_3_579545MHz
-#define MCU_CLOCK		XTAL_4MHz
+#define MCU_CLOCK			MAIN_CLOCK / 3
+#define PIXEL_CLOCK		MAIN_CLOCK / 2
 
 
 /* from video */
@@ -97,8 +98,6 @@ extern UINT8 *ddragon_spriteram;
 extern UINT8 technos_video_hw;
 /* end of extern code & data */
 
-static emu_timer *scanline_timer;
-
 /* private globals */
 static UINT8 dd_sub_cpu_busy;
 static UINT8 sprite_irq, sound_irq, ym_irq;
@@ -141,30 +140,24 @@ INLINE int scanline_to_vcount(int scanline)
 		return (vcount - 0x18) | 0x100;
 }
 
-
-static TIMER_CALLBACK( ddragon_scanline_callback )
+static TIMER_DEVICE_CALLBACK( ddragon_scanline )
 {
 	int scanline = param;
-	int screen_height = video_screen_get_height(machine->primary_screen);
+	int screen_height = video_screen_get_height(timer->machine->primary_screen);
 	int vcount_old = scanline_to_vcount((scanline == 0) ? screen_height - 1 : scanline - 1);
 	int vcount = scanline_to_vcount(scanline);
 
 	/* update to the current point */
 	if (scanline > 0)
-		video_screen_update_partial(machine->primary_screen, scanline - 1);
+		video_screen_update_partial(timer->machine->primary_screen, scanline - 1);
 
 	/* on the rising edge of VBLK (vcount == F8), signal an NMI */
 	if (vcount == 0xf8)
-		cpu_set_input_line(machine->cpu[0], INPUT_LINE_NMI, ASSERT_LINE);
+		cpu_set_input_line(timer->machine->cpu[0], INPUT_LINE_NMI, ASSERT_LINE);
 
 	/* set 1ms signal on rising edge of vcount & 8 */
 	if (!(vcount_old & 8) && (vcount & 8))
-		cpu_set_input_line(machine->cpu[0], M6809_FIRQ_LINE, ASSERT_LINE);
-
-	/* adjust for next scanline */
-	if (++scanline >= screen_height)
-		scanline = 0;
-	timer_adjust_oneshot(scanline_timer, video_screen_get_time_until_pos(machine->primary_screen, scanline, 0), scanline);
+		cpu_set_input_line(timer->machine->cpu[0], M6809_FIRQ_LINE, ASSERT_LINE);
 }
 
 
@@ -180,9 +173,6 @@ static MACHINE_START( ddragon )
 	/* configure banks */
 	memory_configure_bank(machine, 1, 0, 8, memory_region(machine, "main") + 0x10000, 0x4000);
 
-	/* allocate timer for scanlines */
-	scanline_timer = timer_alloc(machine, ddragon_scanline_callback, NULL);
-
 	/* determine the sound CPU index */
 	snd_cpu = cputag_get_cpu(machine, "sound");
 
@@ -201,7 +191,6 @@ static MACHINE_RESET( ddragon )
 	adpcm_end[0] = adpcm_end[1] = 0;
 	adpcm_idle[0] = adpcm_idle[1] = 1;
 	adpcm_data[0] = adpcm_data[1] = -1;
-	timer_adjust_oneshot(scanline_timer, video_screen_get_time_until_pos(machine->primary_screen, 0, 0), 0);
 }
 
 
@@ -978,16 +967,17 @@ static const msm5205_interface msm5205_config =
 static MACHINE_DRIVER_START( ddragon )
 
 	/* basic machine hardware */
- 	MDRV_CPU_ADD("main", HD6309, MAIN_CLOCK)	/* 12MHz / 4 internally */
+ 	MDRV_CPU_ADD("main", HD6309, MAIN_CLOCK)		/* 12 MHz / 4 internally */
 	MDRV_CPU_PROGRAM_MAP(ddragon_map,0)
+	MDRV_TIMER_ADD_SCANLINE("scantimer", ddragon_scanline, "main", 0, 1)
 
-	MDRV_CPU_ADD("sub", HD63701, MAIN_CLOCK/2)	/* 6Mhz / 4 internally */
+	MDRV_CPU_ADD("sub", HD63701, MAIN_CLOCK / 2)	/* 6 MHz / 4 internally */
 	MDRV_CPU_PROGRAM_MAP(sub_map,0)
 
- 	MDRV_CPU_ADD("sound", M6809, MAIN_CLOCK/2)	/* 6MHz / 4 internally */
+ 	MDRV_CPU_ADD("sound", M6809, MAIN_CLOCK / 8)	/* 1.5 MHz */
 	MDRV_CPU_PROGRAM_MAP(sound_map,0)
 
-	MDRV_QUANTUM_TIME(HZ(60000)) /* heavy interleaving to sync up sprite<->main cpu's */
+	MDRV_QUANTUM_TIME(HZ(60000))	/* heavy interleaving to sync up sprite<->main cpu's */
 
 	MDRV_MACHINE_START(ddragon)
 	MDRV_MACHINE_RESET(ddragon)
@@ -998,7 +988,7 @@ static MACHINE_DRIVER_START( ddragon )
 
 	MDRV_SCREEN_ADD("main", RASTER)
 	MDRV_SCREEN_FORMAT(BITMAP_FORMAT_INDEXED16)
-	MDRV_SCREEN_RAW_PARAMS(MAIN_CLOCK/2, 384, 0, 256, 272, 0, 240)
+	MDRV_SCREEN_RAW_PARAMS(PIXEL_CLOCK, 384, 0, 256, 272, 0, 240)
 
 	MDRV_VIDEO_START(ddragon)
 	MDRV_VIDEO_UPDATE(ddragon)
@@ -1025,7 +1015,7 @@ static MACHINE_DRIVER_START( ddragonb )
 	MDRV_IMPORT_FROM(ddragon)
 
 	/* basic machine hardware */
-	MDRV_CPU_REPLACE("sub", M6809, MAIN_CLOCK/2)	/* 6Mhz / 4 internally */
+	MDRV_CPU_REPLACE("sub", M6809, MAIN_CLOCK / 8)	/* 1.5Mhz */
 	MDRV_CPU_PROGRAM_MAP(sub_map,0)
 MACHINE_DRIVER_END
 
@@ -1034,7 +1024,7 @@ static MACHINE_DRIVER_START( ddragnba )
 	MDRV_IMPORT_FROM(ddragon)
 
 	/* basic machine hardware */
- 	MDRV_CPU_REPLACE("sub", M6803, MAIN_CLOCK/2)	/* 6Mhz / 4 internally */
+ 	MDRV_CPU_REPLACE("sub", M6803, MAIN_CLOCK / 2)	/* 6Mhz / 4 internally */
 	MDRV_CPU_PROGRAM_MAP(ddragnba_sub_map,0)
 	MDRV_CPU_IO_MAP(ddragnba_sub_portmap,0)
 MACHINE_DRIVER_END
@@ -1043,13 +1033,14 @@ MACHINE_DRIVER_END
 static MACHINE_DRIVER_START( ddgn6809 )
 
 	/* basic machine hardware */
- 	MDRV_CPU_ADD("main", M6809, MAIN_CLOCK)	/* 12MHz / 4 internally */
+ 	MDRV_CPU_ADD("main", M6809, MAIN_CLOCK / 8)	/* 1.5 MHz */
 	MDRV_CPU_PROGRAM_MAP(ddragon_map,0)
+	MDRV_TIMER_ADD_SCANLINE("scantimer", ddragon_scanline, "main", 0, 1)
 
-	MDRV_CPU_ADD("sub", M6809, MAIN_CLOCK/2)	/* 6Mhz / 4 internally */
+	MDRV_CPU_ADD("sub", M6809, MAIN_CLOCK / 8)	/* 1.5 Mhz */
 	MDRV_CPU_PROGRAM_MAP(sub_map,0)
 
- 	MDRV_CPU_ADD("sound", M6809, MAIN_CLOCK/2)	/* 6MHz / 4 internally */
+ 	MDRV_CPU_ADD("sound", M6809, MAIN_CLOCK / 8)	/* 1.5 MHz */
 	MDRV_CPU_PROGRAM_MAP(sound_map,0)
 
 	MDRV_QUANTUM_TIME(HZ(60000)) /* heavy interleaving to sync up sprite<->main cpu's */
@@ -1063,7 +1054,7 @@ static MACHINE_DRIVER_START( ddgn6809 )
 
 	MDRV_SCREEN_ADD("main", RASTER)
 	MDRV_SCREEN_FORMAT(BITMAP_FORMAT_INDEXED16)
-	MDRV_SCREEN_RAW_PARAMS(MAIN_CLOCK/2, 384, 0, 256, 272, 0, 240)
+	MDRV_SCREEN_RAW_PARAMS(PIXEL_CLOCK, 384, 0, 256, 272, 0, 240)
 
 	MDRV_VIDEO_START(ddragon)
 	MDRV_VIDEO_UPDATE(ddragon)
@@ -1089,10 +1080,11 @@ MACHINE_DRIVER_END
 static MACHINE_DRIVER_START( ddragon2 )
 
 	/* basic machine hardware */
- 	MDRV_CPU_ADD("main", HD6309, MAIN_CLOCK)	/* 12MHz / 4 internally */
+ 	MDRV_CPU_ADD("main", HD6309, MAIN_CLOCK)		/* 12 MHz / 4 internally */
 	MDRV_CPU_PROGRAM_MAP(dd2_map,0)
+	MDRV_TIMER_ADD_SCANLINE("scantimer", ddragon_scanline, "main", 0, 1)
 
-	MDRV_CPU_ADD("sub", Z80, MAIN_CLOCK / 3)	/* 4 MHz */
+	MDRV_CPU_ADD("sub", Z80, MAIN_CLOCK / 3)		/* 4 MHz */
 	MDRV_CPU_PROGRAM_MAP(dd2_sub_map,0)
 
 	MDRV_CPU_ADD("sound", Z80, 3579545)
@@ -1109,7 +1101,7 @@ static MACHINE_DRIVER_START( ddragon2 )
 
 	MDRV_SCREEN_ADD("main", RASTER)
 	MDRV_SCREEN_FORMAT(BITMAP_FORMAT_INDEXED16)
-	MDRV_SCREEN_RAW_PARAMS(MAIN_CLOCK/2, 384, 0, 256, 272, 0, 240)
+	MDRV_SCREEN_RAW_PARAMS(PIXEL_CLOCK, 384, 0, 256, 272, 0, 240)
 
 	MDRV_VIDEO_START(ddragon)
 	MDRV_VIDEO_UPDATE(ddragon)
@@ -2005,9 +1997,6 @@ GAME( 1987, ddragonb, ddragon,  ddragonb, ddragon,  ddragon,  ROT0, "bootleg", "
 GAME( 1987, ddragnba, ddragon,  ddragnba, ddragon,  ddragon,  ROT0, "bootleg", "Double Dragon (bootleg with M6803)", GAME_SUPPORTS_SAVE )
 GAME( 1987, ddgn6809, ddragon,  ddgn6809, ddragon,  ddgn6809, ROT0, "bootleg", "Double Dragon (bootleg with 3xM6809, set 1)", GAME_NOT_WORKING )
 GAME( 1987, dd6809a,  ddragon,  ddgn6809, ddragon,  ddgn6809, ROT0, "bootleg", "Double Dragon (bootleg with 3xM6809, set 2)", GAME_NOT_WORKING )
-
-
-
 GAME( 1988, ddragon2, 0,        ddragon2, ddragon2, ddragon2, ROT0, "Technos", "Double Dragon II - The Revenge (World)", GAME_SUPPORTS_SAVE )
 GAME( 1988, ddragn2u, ddragon2, ddragon2, ddragon2, ddragon2, ROT0, "Technos", "Double Dragon II - The Revenge (US)", GAME_SUPPORTS_SAVE )
 
diff --git a/src/mame/drivers/ddragon3.c b/src/mame/drivers/ddragon3.c
index 480b6eebbad..4a170572319 100644
--- a/src/mame/drivers/ddragon3.c
+++ b/src/mame/drivers/ddragon3.c
@@ -602,12 +602,6 @@ static TIMER_DEVICE_CALLBACK( ddragon3_scanline )
 		video_screen_update_partial(timer->machine->primary_screen, scanline - 1);
 		cpu_set_input_line(timer->machine->cpu[0], 6, ASSERT_LINE);
 	}
-
-	/* Adjust for next scanline */
-	if (++scanline >= video_screen_get_height(timer->machine->primary_screen))
-	{
-		scanline = 0;
-	}
 }
 
 /*************************************
diff --git a/src/mame/drivers/gstream.c b/src/mame/drivers/gstream.c
index 76f06472cd8..4237eac8906 100644
--- a/src/mame/drivers/gstream.c
+++ b/src/mame/drivers/gstream.c
@@ -200,36 +200,71 @@ static READ32_HANDLER( gstream_oki_1_r ) { return okim6295_status_1_r(space, 0);
 static WRITE32_HANDLER( gstream_oki_0_w ) { okim6295_data_0_w(space, 0, data & 0xff); }
 static WRITE32_HANDLER( gstream_oki_1_w ) { okim6295_data_1_w(space, 0, data & 0xff); }
 
-static WRITE32_HANDLER( gstream_oki_4030_w )
+static WRITE32_HANDLER( gstream_oki_banking_w )
 {
-/*
-    // the only nibbles that are written are: 0x6 0x7 0x9 0xa 0xb 0xe 0xd 0xf which should map to the 8 oki banks
+	/* OKI BANKING  (still far from perfect, based on game behaviour)
 
-    static const int bank_lookup[16] = { -1, -1, -1, -1, -1, -1, 0, 1, -1, 2, 3, 4, -1, 5, 6, 7 };
+	The two okis can indifferently play music or samples and are switched on the fly during game
+	This is a preliminary table of the banks:
 
-    static int old_bank_0 = -1;
-    static int old_bank_1 = -1;
+	BANK	MUSIC	SAMPLES
+	 0		   X
+	 1	  X
+	 2	  X 
+	 3	  X
+	 4		   X      
+	 5	  X
+	 6	  X
+	 7	  X
 
-    if(bank_lookup[data & 0xf] != old_bank_0)
-    {
-        old_bank_0 = bank_lookup[data & 0xf];
+	Two nibbles are used in this handler: (data & 0xf) and ((data >> 4) & 0xf)
+	The values for the first nibble are the followings and should map the 8 oki banks:
+	- 0x6, 0x7, 0x9, 0xa, 0xb, 0xd, 0xe, 0xf
+	The values for the second nibble are the followings and should probably be used too:
+	- 0x6, 0x9, 0xa
 
-        if(old_bank_0 != -1)
-            okim6295_set_bank_base(0, old_bank_0 * 0x40000);
-        else
-            logerror("oki_0 banking value = %X\n",data & 0xf);
-    }
+	Same values are redudant, for example:
+	level 2: data = 0x99
+	level 6: data = 0x99 
+	(this means same background music for the two levels - it could be correct, though)
 
-    if(bank_lookup[(data >> 4) & 0xf] != old_bank_1)
-    {
-        old_bank_1 = bank_lookup[(data >> 4) & 0xf];
+	Also with current implementation, using only (data & 0xf), we have to force some values
+	manually, because the correspondent places in the table are already used
 
-        if(old_bank_1 != -1)
-            okim6295_set_bank_base(1, old_bank_1 * 0x40000);
-        else
-            logerror("oki_1 banking value = %X\n",(data >> 4) & 0xf);
-    }
-*/
+	Musics order is completely guessed but close to what the original PCB game should be */
+
+	static const int bank_table_0[16] = { -1, -1, -1, -1, -1, -1, 0, 0, -1, 6, 0, 5, -1, 0, 0, 0 };
+	static const int bank_table_1[16] = { -1, -1, -1, -1, -1, -1, 2, 2, -1, 0, 0, 4, -1, 1, 1, 1 };
+
+	static int bank_0 = 0;
+	static int bank_1 = 0;
+    	
+	//popmessage("oki_0 banking value = %X\noki_1 banking value = %X\n",data & 0xf,(data >> 4) & 0xf);
+        
+	bank_0 = bank_table_0[data & 0xf];
+	bank_1 = bank_table_1[data & 0xf];		// (data >> 4) & 0xf ??
+
+	/* some values are already used in the table, so we force them manually */
+	if ((data == 0x6f) || (data == 0x6e))
+	{
+		bank_0 = 0; 	// level 3b-5a samples
+		bank_1 = 6;		// level 3b-5a music
+	}
+
+	if (data == 0x9b)
+	{
+		bank_0 = 7;		// level 7 music			
+		bank_1 = 0;		// level 7 samples			
+	}
+
+	if (data == 0x9f)
+	{
+		bank_0 = 0;		// end sequence samples			
+		bank_1 = 3;		// end sequence music			
+	}
+
+	okim6295_set_bank_base(0, bank_0 * 0x40000);
+	okim6295_set_bank_base(1, bank_1 * 0x40000);
 }
 
 static WRITE32_HANDLER( gstream_oki_4040_w )
@@ -240,11 +275,11 @@ static WRITE32_HANDLER( gstream_oki_4040_w )
 static ADDRESS_MAP_START( gstream_io, ADDRESS_SPACE_IO, 32 )
 	AM_RANGE(0x4000, 0x4003) AM_READ_PORT("IN0")
 	AM_RANGE(0x4010, 0x4013) AM_READ_PORT("IN1")
-	AM_RANGE(0x4020, 0x4023) AM_READ_PORT("IN2") // extra coin switches etc
-	AM_RANGE(0x4030, 0x4033) AM_WRITE(gstream_oki_4030_w) // ??
-	AM_RANGE(0x4040, 0x4043) AM_WRITE(gstream_oki_4040_w) // ??
-	AM_RANGE(0x4050, 0x4053) AM_READWRITE(gstream_oki_1_r, gstream_oki_1_w) // music
-	AM_RANGE(0x4060, 0x4063) AM_READWRITE(gstream_oki_0_r, gstream_oki_0_w) // samples
+	AM_RANGE(0x4020, 0x4023) AM_READ_PORT("IN2") 	// extra coin switches etc
+	AM_RANGE(0x4030, 0x4033) AM_WRITE(gstream_oki_banking_w) 	// oki banking 
+	AM_RANGE(0x4040, 0x4043) AM_WRITE(gstream_oki_4040_w) 	// ??
+	AM_RANGE(0x4050, 0x4053) AM_READWRITE(gstream_oki_1_r, gstream_oki_1_w) 	// music and samples
+	AM_RANGE(0x4060, 0x4063) AM_READWRITE(gstream_oki_0_r, gstream_oki_0_w) 	// music and samples
 ADDRESS_MAP_END
 
 static INPUT_PORTS_START( gstream )
@@ -434,12 +469,12 @@ static MACHINE_DRIVER_START( gstream )
 	MDRV_SPEAKER_STANDARD_MONO("mono")
 
 	MDRV_SOUND_ADD("oki1", OKIM6295, 1000000) /* 1 Mhz? */
-	MDRV_SOUND_CONFIG(okim6295_interface_pin7low) // pin 7 not verified
-	MDRV_SOUND_ROUTE(ALL_OUTPUTS, "mono", 0.50)
+	MDRV_SOUND_CONFIG(okim6295_interface_pin7high) // pin 7 not verified
+	MDRV_SOUND_ROUTE(ALL_OUTPUTS, "mono", 1.00)
 
 	MDRV_SOUND_ADD("oki2", OKIM6295, 1000000) /* 1 Mhz? */
-	MDRV_SOUND_CONFIG(okim6295_interface_pin7low) // pin 7 not verified
-	MDRV_SOUND_ROUTE(ALL_OUTPUTS, "mono", 0.50)
+	MDRV_SOUND_CONFIG(okim6295_interface_pin7high) // pin 7 not verified
+	MDRV_SOUND_ROUTE(ALL_OUTPUTS, "mono", 1.00)
 MACHINE_DRIVER_END
 
 ROM_START( gstream )
@@ -481,7 +516,7 @@ static READ32_HANDLER( gstream_speedup_r )
 {
 	if (cpu_get_pc(space->cpu)==0xc0001592)
 	{
-		cpu_eat_cycles(space->cpu, 50);
+		cpu_spinuntil_int(space->cpu);
 	}
 
 	return gstream_workram[0xd1ee0/4];
@@ -492,4 +527,5 @@ static DRIVER_INIT( gstream )
 	memory_install_read32_handler(cpu_get_address_space(machine->cpu[0], ADDRESS_SPACE_PROGRAM), 0xd1ee0, 0xd1ee3, 0, 0, gstream_speedup_r );
 
 }
+
 GAME( 2002, gstream, 0, gstream, gstream, gstream, ROT270, "Oriental Soft Japan", "G-Stream G2020", GAME_IMPERFECT_SOUND )
diff --git a/src/mame/drivers/shadfrce.c b/src/mame/drivers/shadfrce.c
index d0a9a36d835..48a8d515582 100644
--- a/src/mame/drivers/shadfrce.c
+++ b/src/mame/drivers/shadfrce.c
@@ -311,12 +311,6 @@ static TIMER_DEVICE_CALLBACK( shadfrce_scanline )
 			cpu_set_input_line(timer->machine->cpu[0], 3, ASSERT_LINE);
 		}
 	}
-
-	/* Adjust for next scanline */
-	if (++scanline >= video_screen_get_height(timer->machine->primary_screen))
-	{
-		scanline = 0;
-	}
 }
 
 
diff --git a/src/mame/drivers/vball.c b/src/mame/drivers/vball.c
index e3d11f9b5dc..ae8e41294db 100644
--- a/src/mame/drivers/vball.c
+++ b/src/mame/drivers/vball.c
@@ -95,6 +95,61 @@ VBlank = 58Hz
 #include "sound/okim6295.h"
 #include "includes/vball.h"
 
+#define MAIN_CLOCK		XTAL_12MHz
+#define CPU_CLOCK			MAIN_CLOCK / 6
+#define PIXEL_CLOCK		MAIN_CLOCK / 2
+
+/* Based on ddragon driver */
+INLINE int scanline_to_vcount(int scanline)
+{
+	int vcount = scanline + 8;
+	if (vcount < 0x100)
+		return vcount;
+	else
+		return (vcount - 0x18) | 0x100;
+}
+
+static TIMER_DEVICE_CALLBACK( vball_scanline )
+{
+	int scanline = param;
+	int screen_height = video_screen_get_height(timer->machine->primary_screen);
+	int vcount_old = scanline_to_vcount((scanline == 0) ? screen_height - 1 : scanline - 1);
+	int vcount = scanline_to_vcount(scanline);
+
+	/* Update to the current point */
+	if (scanline > 0)
+	{
+		video_screen_update_partial(timer->machine->primary_screen, scanline - 1);
+	}
+
+	/* IRQ fires every on every 8th scanline */
+	if (!(vcount_old & 8) && (vcount & 8))
+	{
+		cpu_set_input_line(timer->machine->cpu[0], M6502_IRQ_LINE, ASSERT_LINE);
+	}
+
+	/* NMI fires on scanline 248 (VBL) and is latched */
+	if (vcount == 0xf8)
+	{
+		cpu_set_input_line(timer->machine->cpu[0], INPUT_LINE_NMI, ASSERT_LINE);
+	}
+
+	/* Save the scroll x register value */
+	if (scanline < 256)
+	{ 
+		scrollx[255 - scanline] = (vb_scrollx_hi + vb_scrollx_lo+4);
+	}
+}
+
+static WRITE8_HANDLER( vball_irq_ack_w )
+{
+	if (offset == 0)
+		cpu_set_input_line(space->machine->cpu[0], INPUT_LINE_NMI, CLEAR_LINE);
+
+	else
+		cpu_set_input_line(space->machine->cpu[0], M6502_IRQ_LINE, CLEAR_LINE);
+}
+
 
 /* bit 0 = bank switch
    bit 1 = ?
@@ -118,8 +173,6 @@ static WRITE8_HANDLER( vb_bankswitch_w )
 }
 
 /* The sound system comes all but verbatim from Double Dragon */
-
-
 static WRITE8_HANDLER( cpu_sound_command_w ) {
 	soundlatch_w( space, offset, data );
 	cpu_set_input_line(space->machine->cpu[1], INPUT_LINE_NMI, PULSE_LINE );
@@ -144,6 +197,13 @@ static WRITE8_HANDLER( vb_scrollx_hi_w )
 	//logerror("%04x: vb_scrollx_hi = %d\n",cpu_get_previouspc(space->cpu), vb_scrollx_hi);
 }
 
+static WRITE8_HANDLER(vb_scrollx_lo_w)
+{
+	vb_scrollx_lo = data;
+	//logerror("%04x: vb_scrollx_lo =%d\n",cpu_get_previouspc(space->cpu), vb_scrollx_lo);
+}
+
+
 static ADDRESS_MAP_START( readmem, ADDRESS_SPACE_PROGRAM, 8 )
 	AM_RANGE(0x0000, 0x0fff) AM_READ(SMH_RAM)
 	AM_RANGE(0x1000, 0x1000) AM_READ_PORT("P1")
@@ -170,20 +230,13 @@ static ADDRESS_MAP_START( vball2pj_readmem, ADDRESS_SPACE_PROGRAM, 8 )
 	AM_RANGE(0x8000, 0xffff) AM_READ(SMH_ROM)
 ADDRESS_MAP_END
 
-static WRITE8_HANDLER(vb_scrollx_lo_w)
-{
-	vb_scrollx_lo = data;
-	//logerror("%04x: vb_scrollx_lo =%d\n",cpu_get_previouspc(space->cpu), vb_scrollx_lo);
-}
-
 //Cheaters note: Scores are stored in ram @ 0x57-0x58 (though the space is used for other things between matches)
 static ADDRESS_MAP_START( writemem, ADDRESS_SPACE_PROGRAM, 8 )
 	AM_RANGE(0x0000, 0x07ff) AM_WRITE(SMH_RAM)
 	AM_RANGE(0x0800, 0x08ff) AM_WRITE(SMH_RAM) AM_BASE(&spriteram) AM_SIZE(&spriteram_size)
 	AM_RANGE(0x1008, 0x1008) AM_WRITE(vb_scrollx_hi_w)
 	AM_RANGE(0x1009, 0x1009) AM_WRITE(vb_bankswitch_w)
-	AM_RANGE(0x100a, 0x100a) AM_WRITE(SMH_RAM)
-	AM_RANGE(0x100b, 0x100b) AM_WRITE(SMH_RAM)		//Counts from 0 to 7 continuously
+	AM_RANGE(0x100a, 0x100b) AM_WRITE(vball_irq_ack_w)	/* is there a scanline counter here? */
 	AM_RANGE(0x100c, 0x100c) AM_WRITE(vb_scrollx_lo_w)
 	AM_RANGE(0x100d, 0x100d) AM_WRITE(cpu_sound_command_w)
 	AM_RANGE(0x100e, 0x100e) AM_WRITE(SMH_RAM) AM_BASE(&vb_scrolly_lo)
@@ -369,6 +422,7 @@ static GFXDECODE_START( vb )
 	GFXDECODE_ENTRY( "gfx2", 0, spritelayout, 128, 8 )	/* 16x16 sprites */
 GFXDECODE_END
 
+
 static void vball_irq_handler(running_machine *machine, int irq)
 {
 	cpu_set_input_line(machine->cpu[1], 0 , irq ? ASSERT_LINE : CLEAR_LINE );
@@ -379,23 +433,22 @@ static const ym2151_interface ym2151_config =
 	vball_irq_handler
 };
 
+
 static MACHINE_DRIVER_START( vball )
 
 	/* basic machine hardware */
- 	MDRV_CPU_ADD("main", M6502, 2000000)	/* 2 MHz - measured by guru but it makes the game far far too slow ?! */
+ 	MDRV_CPU_ADD("main", M6502, CPU_CLOCK)	/* 2 MHz - measured by guru but it makes the game far far too slow ?! */
 	MDRV_CPU_PROGRAM_MAP(readmem,writemem)
-	MDRV_CPU_VBLANK_INT_HACK(vball_interrupt,32)	/* ??1 IRQ every 8 visible scanlines, plus NMI for vblank?? */
+	MDRV_TIMER_ADD_SCANLINE("scantimer", vball_scanline, "main", 0, 1)
 
 	MDRV_CPU_ADD("audio", Z80, 3579545)	/* 3.579545 MHz */
 	MDRV_CPU_PROGRAM_MAP(sound_readmem,sound_writemem)
 
 	/* video hardware */
 	MDRV_SCREEN_ADD("main", RASTER)
-	MDRV_SCREEN_REFRESH_RATE(60)
-	MDRV_SCREEN_VBLANK_TIME(ATTOSECONDS_IN_USEC(2500) /* not accurate */)
 	MDRV_SCREEN_FORMAT(BITMAP_FORMAT_INDEXED16)
 	MDRV_SCREEN_SIZE(32*8, 32*8)
-	MDRV_SCREEN_VISIBLE_AREA(1*8, 31*8-1, 1*8, 31*8-1)	/* 240 x 240 */
+	MDRV_SCREEN_RAW_PARAMS(PIXEL_CLOCK, 384, 0, 256, 272, 8, 248)	/* based on ddragon driver */
 
 	MDRV_GFXDECODE(vb)
 	MDRV_PALETTE_LENGTH(256)
@@ -418,41 +471,10 @@ static MACHINE_DRIVER_START( vball )
 MACHINE_DRIVER_END
 
 static MACHINE_DRIVER_START( vball2pj )
+	MDRV_IMPORT_FROM(vball)
 
-	/* basic machine hardware */
- 	MDRV_CPU_ADD("main", M6502, 2000000)	/* 2.0 MHz */
+	MDRV_CPU_MODIFY("main")
 	MDRV_CPU_PROGRAM_MAP(vball2pj_readmem,writemem)
-	MDRV_CPU_VBLANK_INT_HACK(vball_interrupt,32)	/* ??1 IRQ every 8 visible scanlines, plus NMI for vblank?? */
-
-	MDRV_CPU_ADD("audio", Z80, 3579545)	/* 3.579545 MHz */
-	MDRV_CPU_PROGRAM_MAP(sound_readmem,sound_writemem)
-
-	/* video hardware */
-	MDRV_SCREEN_ADD("main", RASTER)
-	MDRV_SCREEN_REFRESH_RATE(60)
-	MDRV_SCREEN_VBLANK_TIME(ATTOSECONDS_IN_USEC(2500) /* not accurate */)
-	MDRV_SCREEN_FORMAT(BITMAP_FORMAT_INDEXED16)
-	MDRV_SCREEN_SIZE(32*8, 32*8)
-	MDRV_SCREEN_VISIBLE_AREA(1*8, 31*8-1, 1*8, 31*8-1)	/* 240 x 240 */
-
-	MDRV_GFXDECODE(vb)
-	MDRV_PALETTE_LENGTH(256)
-
-	MDRV_VIDEO_START(vb)
-	MDRV_VIDEO_UPDATE(vb)
-
-	/* sound hardware */
-	MDRV_SPEAKER_STANDARD_STEREO("left", "right")
-
-	MDRV_SOUND_ADD("ym", YM2151, 3579545)
-	MDRV_SOUND_CONFIG(ym2151_config)
-	MDRV_SOUND_ROUTE(0, "left", 0.60)
-	MDRV_SOUND_ROUTE(1, "right", 0.60)
-
-	MDRV_SOUND_ADD("oki", OKIM6295, 1056000)
-	MDRV_SOUND_CONFIG(okim6295_interface_pin7high)
-	MDRV_SOUND_ROUTE(ALL_OUTPUTS, "left", 1.0)
-	MDRV_SOUND_ROUTE(ALL_OUTPUTS, "right", 1.0)
 MACHINE_DRIVER_END
 
 
diff --git a/src/mame/drivers/wwfsstar.c b/src/mame/drivers/wwfsstar.c
index d09f5b4df3f..3b33260760c 100644
--- a/src/mame/drivers/wwfsstar.c
+++ b/src/mame/drivers/wwfsstar.c
@@ -278,12 +278,6 @@ static TIMER_DEVICE_CALLBACK( wwfsstar_scanline )
 		video_screen_update_partial(timer->machine->primary_screen, scanline - 1);
 		cpu_set_input_line(timer->machine->cpu[0], 6, ASSERT_LINE);
 	}
-
-	/* Adjust for next scanline */
-	if (++scanline >= video_screen_get_height(timer->machine->primary_screen))
-	{
-		scanline = 0;
-	}
 }
 
 static CUSTOM_INPUT( wwfsstar_vblank_r )
diff --git a/src/mame/drivers/wwfwfest.c b/src/mame/drivers/wwfwfest.c
index cb4f90b2020..67d9ee79349 100644
--- a/src/mame/drivers/wwfwfest.c
+++ b/src/mame/drivers/wwfwfest.c
@@ -361,12 +361,6 @@ static TIMER_DEVICE_CALLBACK( wwfwfest_scanline )
 		video_screen_update_partial(timer->machine->primary_screen, scanline - 1);
 		cpu_set_input_line(timer->machine->cpu[0], 3, ASSERT_LINE);
 	}
-
-	/* Adjust for next scanline */
-	if (++scanline >= video_screen_get_height(timer->machine->primary_screen))
-	{
-		scanline = 0;
-	}
 }
 
 /*******************************************************************************
diff --git a/src/mame/drivers/xain.c b/src/mame/drivers/xain.c
index 7996701fc47..acaf517fa3d 100644
--- a/src/mame/drivers/xain.c
+++ b/src/mame/drivers/xain.c
@@ -147,6 +147,11 @@ TODO:
 #include "cpu/m6805/m6805.h"
 #include "sound/2203intf.h"
 
+#define MASTER_CLOCK		XTAL_12MHz
+#define CPU_CLOCK			MASTER_CLOCK / 8
+#define MCU_CLOCK			MASTER_CLOCK / 4
+#define PIXEL_CLOCK		MASTER_CLOCK / 2
+
 static UINT8 *xain_sharedram;
 static int vblank;
 
@@ -164,6 +169,66 @@ WRITE8_HANDLER( xain_flipscreen_w );
 extern UINT8 *xain_charram, *xain_bgram0, *xain_bgram1, xain_pri;
 
 
+/*
+    Based on the Solar Warrior schematics, vertical timing counts as follows:
+
+        08,09,0A,0B,...,FC,FD,FE,FF,E8,E9,EA,EB,...,FC,FD,FE,FF,
+        08,09,....
+
+    Thus, it counts from 08 to FF, then resets to E8 and counts to FF again.
+    This gives (256 - 8) + (256 - 232) = 248 + 24 = 272 total scanlines.
+
+    VBLK is signalled starting when the counter hits F8, and continues through
+    the reset to E8 and through until the next reset to 08 again.
+
+    Since MAME's video timing is 0-based, we need to convert this.
+*/
+
+INLINE int scanline_to_vcount(int scanline)
+{
+	int vcount = scanline + 8;
+	if (vcount < 0x100)
+		return vcount;
+	else
+		return (vcount - 0x18) | 0x100;
+}
+
+static TIMER_DEVICE_CALLBACK( xain_scanline )
+{
+	int scanline = param;
+	int screen_height = video_screen_get_height(timer->machine->primary_screen);
+	int vcount_old = scanline_to_vcount((scanline == 0) ? screen_height - 1 : scanline - 1);
+	int vcount = scanline_to_vcount(scanline);
+
+	/* update to the current point */
+	if (scanline > 0)
+	{
+		video_screen_update_partial(timer->machine->primary_screen, scanline - 1);
+	}
+
+	/* FIRQ (IMS) fires every on every 8th scanline (except 0) */
+	if (!(vcount_old & 8) && (vcount & 8))
+	{
+		cpu_set_input_line(timer->machine->cpu[0], M6809_FIRQ_LINE, ASSERT_LINE);
+	}
+
+	/* NMI fires on scanline 248 (VBL) and is latched */
+	if (vcount == 0xf8)
+	{
+		cpu_set_input_line(timer->machine->cpu[0], INPUT_LINE_NMI, ASSERT_LINE);
+	}
+
+	/* VBLANK input bit is held high from scanlines 248-255 */
+	if (vcount >= 248-1)	// -1 is a hack - see notes above
+	{
+		vblank = 1;
+	}
+	else
+	{
+		vblank = 0;
+	}
+}
+
 static READ8_HANDLER( xain_sharedram_r )
 {
 	return xain_sharedram[offset];
@@ -248,24 +313,6 @@ static CUSTOM_INPUT( xain_vblank_r )
 	return vblank;
 }
 
-static INTERRUPT_GEN( xain_interrupt )
-{
-	int scanline = 255 - cpu_getiloops(device);
-
-	/* FIRQ (IMS) fires every on every 8th scanline (except 0) */
-	if (scanline & 0x08)
-		cpu_set_input_line(device, M6809_FIRQ_LINE, ASSERT_LINE);
-
-	/* NMI fires on scanline 248 (VBL) and is latched */
-	if (scanline == 248)
-		cpu_set_input_line(device, INPUT_LINE_NMI, ASSERT_LINE);
-
-	/* VBLANK input bit is held high from scanlines 248-255 */
-	if (scanline >= 248-1) // -1 is a hack - see notes above
-		vblank = 1;
-	else
-		vblank = 0;
-}
 
 static ADDRESS_MAP_START( main_map, ADDRESS_SPACE_PROGRAM, 8 )
 	AM_RANGE(0x0000, 0x1fff) AM_READWRITE(xain_sharedram_r, xain_sharedram_w) AM_BASE(&xain_sharedram)
@@ -293,7 +340,7 @@ static ADDRESS_MAP_START( main_map, ADDRESS_SPACE_PROGRAM, 8 )
 	AM_RANGE(0x3c00, 0x3dff) AM_WRITE(paletteram_xxxxBBBBGGGGRRRR_split1_w) AM_BASE(&paletteram)
 	AM_RANGE(0x3e00, 0x3fff) AM_WRITE(paletteram_xxxxBBBBGGGGRRRR_split2_w) AM_BASE(&paletteram_2)
 	AM_RANGE(0x4000, 0x7fff) AM_READ(SMH_BANK1)
-	AM_RANGE(0x4000, 0xffff) AM_ROM
+	AM_RANGE(0x8000, 0xffff) AM_ROM
 ADDRESS_MAP_END
 
 static ADDRESS_MAP_START( cpu_map_B, ADDRESS_SPACE_PROGRAM, 8 )
@@ -302,7 +349,7 @@ static ADDRESS_MAP_START( cpu_map_B, ADDRESS_SPACE_PROGRAM, 8 )
 	AM_RANGE(0x2800, 0x2800) AM_WRITE(xain_irqB_clear_w)
 	AM_RANGE(0x3000, 0x3000) AM_WRITE(xainCPUB_bankswitch_w)
 	AM_RANGE(0x4000, 0x7fff) AM_READ(SMH_BANK2)
-	AM_RANGE(0x4000, 0xffff) AM_ROM
+	AM_RANGE(0x8000, 0xffff) AM_ROM
 ADDRESS_MAP_END
 
 #if 0
@@ -322,6 +369,7 @@ static ADDRESS_MAP_START( sound_map, ADDRESS_SPACE_PROGRAM, 8 )
 	AM_RANGE(0x4000, 0xffff) AM_ROM
 ADDRESS_MAP_END
 
+
 static INPUT_PORTS_START( xsleena )
 	PORT_START("P1")
 	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_JOYSTICK_RIGHT ) PORT_8WAY
@@ -399,7 +447,6 @@ static INPUT_PORTS_START( xsleena )
 INPUT_PORTS_END
 
 
-
 static const gfx_layout charlayout =
 {
 	8,8,
@@ -430,7 +477,6 @@ static GFXDECODE_START( xain )
 GFXDECODE_END
 
 
-
 /* handler called by the 2203 emulator when the internal timers cause an IRQ */
 static void irqhandler(running_machine *machine, int irq)
 {
@@ -447,30 +493,29 @@ static const ym2203_interface ym2203_config =
 	irqhandler
 };
 
-
 static MACHINE_START( xsleena )
 {
-	const address_space *space = cpu_get_address_space(machine->cpu[0], ADDRESS_SPACE_PROGRAM);
+	const address_space *space_main = cpu_get_address_space(machine->cpu[0], ADDRESS_SPACE_PROGRAM);
+	const address_space *space_sub = cpu_get_address_space(machine->cpu[1], ADDRESS_SPACE_PROGRAM);
 	/* initialize the bank pointers */
-	xainCPUA_bankswitch_w(space,0,0);
-	xainCPUB_bankswitch_w(space,0,0);
+	xainCPUA_bankswitch_w(space_main,0,0);
+	xainCPUB_bankswitch_w(space_sub,0,0);
 }
 
-
 static MACHINE_DRIVER_START( xsleena )
 
 	/* basic machine hardware */
-	MDRV_CPU_ADD("main", M6809, 1500000)	/* Confirmed 1.5MHz */
+	MDRV_CPU_ADD("main", M6809, CPU_CLOCK)	/* Confirmed 1.5MHz */
 	MDRV_CPU_PROGRAM_MAP(main_map,0)
-	MDRV_CPU_VBLANK_INT_HACK(xain_interrupt,256)
+	MDRV_TIMER_ADD_SCANLINE("scantimer", xain_scanline, "main", 0, 1)
 
-	MDRV_CPU_ADD("sub", M6809, 1500000)	/* Confirmed 1.5MHz */
+	MDRV_CPU_ADD("sub", M6809, CPU_CLOCK)	/* Confirmed 1.5MHz */
 	MDRV_CPU_PROGRAM_MAP(cpu_map_B,0)
 
-	MDRV_CPU_ADD("audio", M6809, 1500000)	/* Confirmed 1.5MHz */
+	MDRV_CPU_ADD("audio", M6809, CPU_CLOCK)	/* Confirmed 1.5MHz */
 	MDRV_CPU_PROGRAM_MAP(sound_map,0)
 
-//  MDRV_CPU_ADD("mcu", M68705, 3000000)    /* Confirmed 3MHz */
+//  MDRV_CPU_ADD("mcu", M68705, MCU_CLOCK)    /* Confirmed 3MHz */
 //  MDRV_CPU_PROGRAM_MAP(mcu_map,0)
 
 	MDRV_MACHINE_START(xsleena)
@@ -479,11 +524,8 @@ static MACHINE_DRIVER_START( xsleena )
 
 	/* video hardware */
 	MDRV_SCREEN_ADD("main", RASTER)
-	MDRV_SCREEN_REFRESH_RATE(57)
-	MDRV_SCREEN_VBLANK_TIME(ATTOSECONDS_IN_USEC(0))
 	MDRV_SCREEN_FORMAT(BITMAP_FORMAT_INDEXED16)
-	MDRV_SCREEN_SIZE(32*8, 32*8)
-	MDRV_SCREEN_VISIBLE_AREA(0*8, 32*8-1, 2*8, 30*8-1)
+	MDRV_SCREEN_RAW_PARAMS(PIXEL_CLOCK, 384, 0, 256, 272, 8, 248)	/* based on ddragon driver */
 
 	MDRV_GFXDECODE(xain)
 	MDRV_PALETTE_LENGTH(512)
@@ -509,7 +551,6 @@ static MACHINE_DRIVER_START( xsleena )
 MACHINE_DRIVER_END
 
 
-
 /***************************************************************************
 
   Game driver(s)
@@ -676,7 +717,6 @@ ROM_START( solarwar )
 ROM_END
 
 
-
 static DRIVER_INIT( xsleena )
 {
 	UINT8 *RAM = memory_region(machine, "main");
@@ -704,7 +744,6 @@ static DRIVER_INIT( solarwar )
 }
 
 
-
 GAME( 1986, xsleena,  0,       xsleena, xsleena, xsleena,  ROT0, "Technos", "Xain'd Sleena", 0 )
 GAME( 1986, xsleenab, xsleena, xsleena, xsleena, 0,        ROT0, "bootleg", "Xain'd Sleena (bootleg)", 0 )
 GAME( 1986, solarwar, xsleena, xsleena, xsleena, solarwar, ROT0, "[Technos] Taito (Memetron license)", "Solar-Warrior", 0 )
diff --git a/src/mame/includes/vball.h b/src/mame/includes/vball.h
index 1e5b8a00a0d..2edc958c08b 100644
--- a/src/mame/includes/vball.h
+++ b/src/mame/includes/vball.h
@@ -7,6 +7,7 @@ extern int vb_scrollx_hi;
 extern int vb_scrolly_hi;
 extern int vb_scrollx_lo;
 extern int vball_gfxset;
+extern int scrollx[256];
 
 VIDEO_START( vb );
 VIDEO_UPDATE( vb );
@@ -15,5 +16,3 @@ void vb_spprombank_w(running_machine *machine, int bank);
 WRITE8_HANDLER( vb_attrib_w );
 WRITE8_HANDLER( vb_videoram_w );
 void vb_mark_all_dirty(void);
-
-INTERRUPT_GEN( vball_interrupt );
diff --git a/src/mame/video/vball.c b/src/mame/video/vball.c
index a076d778ce9..285b6225f7f 100644
--- a/src/mame/video/vball.c
+++ b/src/mame/video/vball.c
@@ -14,6 +14,7 @@
 int vb_scrollx_hi=0;
 int vb_scrollx_lo=0;
 int vb_scrolly_hi=0;
+int scrollx[256];
 
 UINT8 *vb_scrolly_lo;
 UINT8 *vb_videoram;
@@ -23,7 +24,6 @@ static int vb_bgprombank=0xff;
 static int vb_spprombank=0xff;
 
 static tilemap *bg_tilemap;
-static int scrollx[32];
 
 /***************************************************************************
 
@@ -168,7 +168,7 @@ VIDEO_UPDATE( vb )
 	tilemap_set_scrolly(bg_tilemap,0,vb_scrolly_hi + *vb_scrolly_lo);
 
 	/*To get linescrolling to work properly, we must ignore the 1st two scroll values, no idea why! -SJE */
-	for (i = 2;i < 32;i++) {
+	for (i = 2; i < 256; i++) {
 		tilemap_set_scrollx(bg_tilemap,i,scrollx[i-2]);
 		//logerror("scrollx[%d] = %d\n",i,scrollx[i]);
 	}
@@ -176,18 +176,3 @@ VIDEO_UPDATE( vb )
 	draw_sprites(screen->machine,bitmap,cliprect);
 	return 0;
 }
-
-
-/*I don't really understand what the proper timing of this should be,
-  but after TONS of testing, the tilemap individual line scrolling works as long as flip screen is not set -SJE
-*/
-INTERRUPT_GEN( vball_interrupt )
-{
-	int line = 31 - cpu_getiloops(device);
-	if (line < 13)
-		cpu_set_input_line(device, M6502_IRQ_LINE, HOLD_LINE);
-	else if (line == 13)
-		cpu_set_input_line(device, INPUT_LINE_NMI, PULSE_LINE);
-	//save the scroll x register value
-	if(line<32) scrollx[31-line] = (vb_scrollx_hi + vb_scrollx_lo+4);
-}