02918: psychosj psychos: Title screen graphic glitch

src/mame/drivers/snk.c

@@ -247,13 +247,14 @@ TODO:
   snk68.c for another game that needs this). tdfever dots still flicker a lot,
   however I'm not sure if this is an emulation bug or the real game behaviour.
 
-- psychos: in all games using the gwar video, palette colors 0x180-0x1ff are not
+- psychos: the pcb has glitches (colored lines of length up to 16 pixels) during
-  used because bit 3 of the sprite attribute is used for tile bank select instead.
+  scrolling on the left side of the screen. This doesn't happen in the emulation
-  In all games, those colors 0x180-0x1ff are a copy of 0x100-0x17f so even if the
+  so it might be an unemulated  hardware bug.
-  bit was wired to the palette, it would make no difference. In psychos, however,
+
-  the colors are different. Game colors appear to be correct as they are, and
+- worldwar: at the beginning of the game, the bottom 16 pixels of the bg are
-  connecting bit 3 would break them, so it's unknown if colors 0x180-0x1ff should
+  blank. I think that this is related to the psychos glitch above, i.e. the pcb
-  be used and how.
+  wouldn't display that area correctly anyway so operators were supposed to
+  adjust the screen size to make them invisible.
 
 ***************************************************************************/
 
@@ -3549,9 +3550,8 @@ GFXDECODE_END
 static GFXDECODE_START( gwar )
 	GFXDECODE_ENTRY( "tx_tiles",   0, charlayout_4bpp,      0x000, 0x100>>4 )
 	GFXDECODE_ENTRY( "bg_tiles",   0, tilelayout_4bpp,      0x300, 0x100>>4 )
-	GFXDECODE_ENTRY( "sp16_tiles", 0, spritelayout_4bpp,    0x100, 0x080>>4 )
+	GFXDECODE_ENTRY( "sp16_tiles", 0, spritelayout_4bpp,    0x100, 0x100>>4 )
 	GFXDECODE_ENTRY( "sp32_tiles", 0, bigspritelayout_4bpp, 0x200, 0x100>>4 )
-	/* what about colors 0x180-0x1ff? */
 GFXDECODE_END
 
 static GFXDECODE_START( tdfever )
@@ -3880,10 +3880,9 @@ static MACHINE_DRIVER_START( bermudat )
 	MDRV_SCREEN_ADD("main", RASTER)
 	MDRV_SCREEN_REFRESH_RATE(60)
 	MDRV_SCREEN_FORMAT(BITMAP_FORMAT_INDEXED16)
-	// visible area uncertain but this size avoids glitches at the bottom of the screen
+	// this visible area matches the psychos pcb
-	// in worldwar at the beginning of the game
 	MDRV_SCREEN_SIZE(50*8, 28*8)
-	MDRV_SCREEN_VISIBLE_AREA(2*8, 48*8-1, 0*8, 28*8-1)
+	MDRV_SCREEN_VISIBLE_AREA(0*8, 50*8-1, 0*8, 28*8-1)
 
 	MDRV_GFXDECODE(gwar)
 	MDRV_PALETTE_LENGTH(0x400)
@@ -3905,6 +3904,15 @@ static MACHINE_DRIVER_START( bermudat )
 MACHINE_DRIVER_END
 
 
+static MACHINE_DRIVER_START( psychos )
+
+	MDRV_IMPORT_FROM(bermudat)
+
+	/* video hardware */
+	MDRV_VIDEO_START(psychos)
+MACHINE_DRIVER_END
+
+
 static MACHINE_DRIVER_START( gwar )
 
 	MDRV_IMPORT_FROM(bermudat)
@@ -6190,8 +6198,8 @@ GAME( 1987, bermudat, 0,        bermudat, bermudat, 0,        ROT270, "SNK", "Be
 GAME( 1987, bermudaj, bermudat, bermudat, bermudat, 0,        ROT270, "SNK", "Bermuda Triangle (Japan)", 0 )
 GAME( 1987, worldwar, 0,        bermudat, worldwar, 0,        ROT270, "SNK", "World Wars (World?)", 0 )
 GAME( 1987, bermudaa, worldwar, bermudat, bermudaa, 0,        ROT270, "SNK", "Bermuda Triangle (World Wars) (US)", 0 )
-GAME( 1987, psychos,  0,        bermudat, psychos,  0,        ROT0,   "SNK", "Psycho Soldier (US)", 0 )
+GAME( 1987, psychos,  0,        psychos,  psychos,  0,        ROT0,   "SNK", "Psycho Soldier (US)", 0 )
-GAME( 1987, psychosj, psychos,  bermudat, psychos,  0,        ROT0,   "SNK", "Psycho Soldier (Japan)", 0 )
+GAME( 1987, psychosj, psychos,  psychos,  psychos,  0,        ROT0,   "SNK", "Psycho Soldier (Japan)", 0 )
 GAME( 1987, gwar,     0,        gwar,     gwar,     0,        ROT270, "SNK", "Guerrilla War (US)", 0 )
 GAME( 1987, gwarj,    gwar,     gwar,     gwar,     0,        ROT270, "SNK", "Guevara (Japan)", 0 )
 GAME( 1987, gwara,    gwar,     gwara,    gwar,     0,        ROT270, "SNK", "Guerrilla War (Version 1)", 0 )

src/mame/includes/snk.h

@@ -25,6 +25,7 @@ extern VIDEO_START( aso );
 extern VIDEO_START( tnk3 );
 extern VIDEO_START( ikari );
 extern VIDEO_START( gwar );
+extern VIDEO_START( psychos );
 extern VIDEO_START( tdfever );
 
 extern VIDEO_UPDATE( marvins );

src/mame/video/snk.c

@@ -35,6 +35,7 @@ static UINT8 sprite_split_point;
 static int num_sprites, yscroll_mask;
 static UINT32 bg_tile_offset;
 static UINT32 tx_tile_offset;
+static int is_psychos;
 
 static UINT8 empty_tile[16*16];
 static UINT8 drawmode_table[16];
@@ -169,6 +170,10 @@ static TILE_GET_INFO( gwar_get_bg_tile_info )
 	int attr = snk_bg_videoram[2*tile_index+1];
 	int code = snk_bg_videoram[2*tile_index] | ((attr & 0x0f) << 8);
 	int color = (attr & 0xf0) >> 4;
+
+	if (is_psychos)	// psychos has a separate palette bank bit
+		color &= 7;
+
 	SET_TILE_INFO(1,
 			code,
 			color,
@@ -354,6 +359,14 @@ VIDEO_START( gwar )
 	tilemap_set_scrolldy(bg_tilemap,  0, -32);
 
 	tx_tile_offset = 0;
+
+	is_psychos = 0;
+}
+
+VIDEO_START( psychos )
+{
+	VIDEO_START_CALL(gwar);
+	is_psychos = 1;
 }
 
 VIDEO_START( tdfever )
@@ -595,6 +608,9 @@ WRITE8_HANDLER( gwar_tx_bank_w )
 		tx_tile_offset = (data & 0x30) << 4;
 		tilemap_mark_all_tiles_dirty(tx_tilemap);
 	}
+
+	if (is_psychos)
+		tilemap_set_palette_offset(bg_tilemap, (data & 0x80));
 }
 
 WRITE8_HANDLER( gwar_videoattrs_w )
@@ -849,6 +865,8 @@ static void tdfever_draw_sprites(running_machine *machine, bitmap_t *bitmap, con
 			case 16:
 				tile_number |= ((attributes & 0x08) << 5) | ((attributes & 0x60) << 4);
 				color &= 7;	// attribute bit 3 is used for bank select
+				if (from == 0)
+					color |= 8;	// low priority sprites use the other palette bank
 				break;
 
 			case 32: