More NES work: [Robert Bohms]

* Fixes bug in nes_apu that caused errors reading $4015
* Adds length counter status bits to $4015
* Fixes 4-screen mirroring (PPU regression)
* Fixed cham24

Also, I fixed the tab lengths in nes_apu.c

src/emu/sound/nes_defs.h

@@ -50,8 +50,8 @@ typedef UINT8         boolean;
 
 typedef struct queue_s
 {
-  int pos;
+	int pos;
-  unsigned char reg,val;
+	unsigned char reg,val;
 } queue_t;
 
 #endif
@@ -86,88 +86,89 @@ typedef struct queue_s
 /* Square Wave */
 typedef struct square_s
 {
-   uint8 regs[4];
+	uint8 regs[4];
-   int vbl_length;
+	int vbl_length;
-   int freq;
+	int freq;
-   float phaseacc;
+	float phaseacc;
-   float output_vol;
+	float output_vol;
-   float env_phase;
+	float env_phase;
-   float sweep_phase;
+	float sweep_phase;
-   uint8 adder;
+	uint8 adder;
-   uint8 env_vol;
+	uint8 env_vol;
-   boolean enabled;
+	boolean enabled;
 } square_t;
 
 /* Triangle Wave */
 typedef struct triangle_s
 {
-   uint8 regs[4]; /* regs[1] unused */
+	uint8 regs[4]; /* regs[1] unused */
-   int linear_length;
+	int linear_length;
-   int vbl_length;
+	int vbl_length;
-   int write_latency;
+	int write_latency;
-   float phaseacc;
+	float phaseacc;
-   float output_vol;
+	float output_vol;
-   uint8 adder;
+	uint8 adder;
-   boolean counter_started;
+	boolean counter_started;
-   boolean enabled;
+	boolean enabled;
 } triangle_t;
 
 /* Noise Wave */
 typedef struct noise_s
 {
-   uint8 regs[4]; /* regs[1] unused */
+	uint8 regs[4]; /* regs[1] unused */
-   int cur_pos;
+	int cur_pos;
-   int vbl_length;
+	int vbl_length;
-   float phaseacc;
+	float phaseacc;
-   float output_vol;
+	float output_vol;
-   float env_phase;
+	float env_phase;
-   uint8 env_vol;
+	uint8 env_vol;
-   boolean enabled;
+	boolean enabled;
 } noise_t;
 
 /* DPCM Wave */
 typedef struct dpcm_s
 {
-   uint8 regs[4];
+	uint8 regs[4];
-   uint32 address;
+	uint32 address;
-   uint32 length;
+	uint32 length;
-   int bits_left;
+	int bits_left;
-   float phaseacc;
+	float phaseacc;
-   float output_vol;
+	float output_vol;
-   uint8 cur_byte;
+	uint8 cur_byte;
-   boolean enabled;
+	boolean enabled;
-   boolean irq_occurred;
+	boolean irq_occurred;
-   const address_space *memory;
+	const address_space *memory;
-   signed char vol;
+	signed char vol;
 } dpcm_t;
 
 /* APU type */
 typedef struct apu
 {
-   /* Sound channels */
+	/* Sound channels */
-   square_t   squ[2];
+	square_t   squ[2];
-   triangle_t tri;
+	triangle_t tri;
-   noise_t    noi;
+	noise_t    noi;
-   dpcm_t     dpcm;
+	dpcm_t     dpcm;
 
-   /* APU registers */
+	/* APU registers */
-   unsigned char regs[0x17];
+	unsigned char regs[0x17];
 
-   /* Sound pointers */
+	/* Sound pointers */
-   void *buffer;
+	void *buffer;
 
 #ifdef USE_QUEUE
 
-   /* Event queue */
+	/* Event queue */
-   queue_t queue[QUEUE_SIZE];
+	queue_t queue[QUEUE_SIZE];
-   int head,tail;
+	int head, tail;
 
 #else
 
-   int buf_pos;
+	int buf_pos;
 
 #endif
 
+	int step_mode;
 } apu_t;
 
 /* CONSTANTS */

src/mame/drivers/cham24.c

@@ -244,12 +244,6 @@ static const nes_interface cham24_interface_1 =
 
 static MACHINE_RESET( cham24 )
 {
-	/* switch PRG rom */
-	UINT8* dst = memory_region(machine, "maincpu");
-	UINT8* src = memory_region(machine, "user1");
-
-	memcpy(&dst[0x8000], &src[0x0f8000], 0x4000);
-	memcpy(&dst[0xc000], &src[0x0f8000], 0x4000);
 }
 
 static PALETTE_INIT( cham24 )
@@ -282,8 +276,16 @@ static VIDEO_UPDATE( cham24 )
 	return 0;
 }
 
-static DRIVER_INIT( cham24 )
+
+static MACHINE_START( cham24 )
 {
+	/* switch PRG rom */
+	UINT8* dst = memory_region(machine, "maincpu");
+	UINT8* src = memory_region(machine, "user1");
+
+	memcpy(&dst[0x8000], &src[0x0f8000], 0x4000);
+	memcpy(&dst[0xc000], &src[0x0f8000], 0x4000);
+
 	/* uses 8K swapping, all ROM!*/
 	memory_install_readwrite8_handler(cpu_get_address_space(cputag_get_cpu(machine, "ppu"), ADDRESS_SPACE_PROGRAM), 0x0000, 0x1fff, 0, 0, SMH_BANK(1), 0);
 	memory_set_bankptr(machine, 1, memory_region(machine, "gfx1"));
@@ -299,6 +301,10 @@ static DRIVER_INIT( cham24 )
 	memory_install_readwrite8_handler(cpu_get_address_space(cputag_get_cpu(machine, "ppu"), ADDRESS_SPACE_PROGRAM), 0x2000, 0x3eff, 0, 0, nt_r, nt_w);
 }
 
+static DRIVER_INIT( cham24 )
+{
+}
+
 static GFXDECODE_START( cham24 )
 	/* none, the ppu generates one */
 GFXDECODE_END
@@ -309,6 +315,7 @@ static MACHINE_DRIVER_START( cham24 )
 	MDRV_CPU_PROGRAM_MAP(cham24_map)
 
 	MDRV_MACHINE_RESET( cham24 )
+	MDRV_MACHINE_START( cham24 )
 
 	/* video hardware */
 	MDRV_SCREEN_ADD("screen", RASTER)

src/mame/video/ppu2c0x.c

@@ -19,6 +19,7 @@
 
     * Micro Machines has minor rendering glitches (needs better timing).
     * Mach Rider has minor road rendering glitches (needs better timing).
+    * Rad Racer demonstrates road glitches: it changes horizontal scrolling mid-line.
 
 ******************************************************************************/
 
@@ -380,7 +381,6 @@ static void draw_background( const device_config *device, UINT8 *line_priority )
 
 	const pen_t *color_table;
 	const pen_t *paldata;
-	// const UINT8 *sd;
 
 	int tilecount = 0;
 
@@ -447,19 +447,16 @@ static void draw_background( const device_config *device, UINT8 *line_priority )
 
 		if (start_x < VISIBLE_SCREEN_WIDTH)
 		{
-			UINT8 plane1, plane2;	// use extended size so I can shift!
+			UINT8 plane1, plane2;
 			paldata = &color_table[4 * (((color_byte >> color_bits) & 0x03))];
-			// start = scroll_y_fine * line_modulo;
 
 			// need to read 0x0000 or 0x1000 + 16*nametable data
 			address = ((this_ppu->tile_page) ? 0x1000 : 0) + (page2 * 16);
 			// plus something that accounts for y
-			// address -= (scanline % 8);
 			address += scroll_y_fine;
 
 			plane1 = memory_read_byte(device->space[0], (address & 0x1fff));
 			plane2 = memory_read_byte(device->space[0], (address + 8) & 0x1fff);
-			// plane2 = plane2 << 1;
 
 			/* render the pixel */
 			for (i = 0; i < 8; i++)
@@ -618,30 +615,23 @@ static void draw_sprites( const device_config *device, UINT8 *line_priority )
 		plane1 = memory_read_byte(device->space[0], (index1 + sprite_line) & 0x1fff);
 		plane2 = memory_read_byte(device->space[0], (index1 + sprite_line + 8) & 0x1fff);
 
-//      sd = gfx_element_get_data(device->machine->gfx[gfx_bank], index1 % total_elements) + start;
-//      if (size > 8)
-//          gfx_element_get_data(device->machine->gfx[gfx_bank], (index1 + 1) % total_elements);
-
 		if (pri)
 		{
 			/* draw the low-priority sprites */
 			for (pixel = 0; pixel < 8; pixel++)
 			{
-//              UINT8 pixelData = flipx ? sd[7-pixel] : sd[pixel];
 				UINT8 pixelData;
 				if (flipx)
 				{
 					pixelData = (plane1 & 1) + ((plane2 & 1) << 1);
 					plane1 = plane1 >> 1;
 					plane2 = plane2 >> 1;
-					// sd[7 - pixel]
 				}
 				else
 				{
 					pixelData = ((plane1 >> 7) & 1) | (((plane2 >> 7) & 1) << 1);
 					plane1 = plane1 << 1;
 					plane2 = plane2 << 1;
-					// sd[pixel];
 				}
 
 				/* is this pixel non-transparent? */
@@ -1037,11 +1027,11 @@ READ8_HANDLER( ppu2c0x_palette_read )
 {
 	ppu2c0x_chip *this_ppu = get_token(space->cpu);
 	{
-		// it's a palette
-		// ERROR: doesn't currently handle monochrome!
 		if (this_ppu->regs[PPU_CONTROL1] & PPU_CONTROL1_DISPLAY_MONO)
 			return (this_ppu->palette_ram[offset & 0x1f] & 0x30);
-		else return (this_ppu->palette_ram[offset & 0x1f] & 0x3f);
+
+		else 
+			return (this_ppu->palette_ram[offset & 0x1f] & 0x3f);
 	}
 }
 
@@ -1242,9 +1232,6 @@ WRITE8_DEVICE_HANDLER( ppu2c0x_w )
 				{
 					/* store the data */
 					memory_write_byte(device->space[0], tempAddr, data);
-
-					/* mark the char dirty */
-					// gfx_element_mark_dirty(device->machine->gfx[intf->gfx_layout_number], tempAddr >> 4);
 				}
 
 				else
@@ -1273,28 +1260,14 @@ void ppu2c0x_spriteram_dma( const address_space *space, const device_config *dev
 	int i;
 	int address = page << 8;
 
-//  logerror("sprite DMA: %d (scanline: %d)\n", page, this_ppu->scanline);
 	for (i = 0; i < SPRITERAM_SIZE; i++)
 	{
 		UINT8 spriteData = memory_read_byte(space, address + i);
 		memory_write_byte(space, 0x2004, spriteData);
-//      ppu2c0x_w(device, PPU_SPRITE_DATA, spriteData);
 	}
 
 	// should last 513 CPU cycles.
 	cpu_adjust_icount(space->cpu, -513);
-
-	// ????TODO : need to account for PPU rendering - this is roughly 4.5 scanlines eaten up.
-	// Because the DMA is only useful during vblank, this may not be strictly necessary since
-	// the scanline timers should catch us up before drawing actually happens.
-#if 0
-{
-	scanline_callback(device);
-	scanline_callback(device);
-	scanline_callback(device);
-	scanline_callback(device);
-}
-#endif
 }
 
 /*************************************