another megadriv.c update

src/mame/drivers/megadriv.c

@@ -274,6 +274,7 @@ a tilemap-like structure, from which data is copied)
 #ifdef MESS
 #include "devices/chd_cd.h"
 #endif
+#include "sound/rf5c68.h"
 
 #define MEGADRIV_VDP_VRAM(address) megadrive_vdp_vram[(address)&0x7fff]
 
@@ -3936,6 +3937,39 @@ static READ16_HANDLER( scd_a12002_memory_mode_r )
 		   ((segacd_maincpu_has_ram_access) << 0);
 }
 
+
+/* I'm still not 100% clear how this works, the sources I have are a bit vague,
+   it might still be incorrect in both modes
+ */
+
+// DMNA = Decleration Mainram No Access (bit 0)
+// RET = Return access (bit 1)
+
+/* In Mode 0
+
+*/
+
+/* In Mode 1
+
+
+RET
+
+0 = Main CPU Accesses WordRam0 (1st Half of WordRAM)
+    Sub CPU  Accesses WordRam1 (2nd Half of WordRAM)
+	
+1 = Main CPU Accesses WordRam1 (2nd Half of WordRAM)
+    Sub  CPU Accesses WordRam0 (1st Half of WordRAM)
+	
+DMNA
+
+Setting this bis sends a Swap request to the SUB-CPU (Main CPU access only?)
+  1 = Swap Reqested / In Progress
+  0 = Swap Complete
+
+ (personal note, is this just a software flag? in this mode? sub p11/p12)
+
+*/
+
 static WRITE16_HANDLER( scd_a12002_memory_mode_w )
 {
 	//printf("scd_a12002_memory_mode_w %04x %04x\n", data, mem_mask);
@@ -3946,7 +3980,7 @@ static WRITE16_HANDLER( scd_a12002_memory_mode_w )
 		//if (data&0x0001) printf("ret bit set (invalid? can't set from main68k?)\n");
 		if (data&0x0002)
 		{
-			//printf("dmn set (swap requested)\n"); // give ram to sub?
+			//printf("dmna set (swap requested)\n"); // give ram to sub?
 
 			// this should take some time?
 			segacd_maincpu_has_ram_access = 0;
@@ -4001,7 +4035,7 @@ static WRITE16_HANDLER( segacd_sub_memory_mode_w )
 		}
 
 
-		//if (data&0x0002) printf("dmn set (swap requested) (invalid, can't be set from sub68k?\n");
+		//if (data&0x0002) printf("dmna set (swap requested) (invalid, can't be set from sub68k?\n");
 
 		//if (data&0x0004)
 		{
@@ -4281,9 +4315,19 @@ static READ16_HANDLER( segacd_main_dataram_part1_r )
 	}
 	else if (segacd_ram_mode==1)
 	{
-		printf("Unspported: segacd_main_dataram_part1_r in mode 1\n");
+
+		if (offset<0x20000/2)
+		{
+			// wordram accees
+			printf("Unspported: segacd_main_dataram_part1_r (word RAM) in mode 1\n");
 			return 0x0000;
 		}
+		else
+		{
+			printf("Unspported: segacd_main_dataram_part1_r (Cell rearranged RAM) in mode 1\n"); 
+			return 0x0000;
+		}		
+	}
 
 	return 0x0000;
 }
@@ -4305,7 +4349,15 @@ static WRITE16_HANDLER( segacd_main_dataram_part1_w )
 	}
 	else if (segacd_ram_mode==1)
 	{
-		printf("Unspported: segacd_main_dataram_part1_w in mode 1\n");
+		if (offset<0x20000/2)
+		{
+			printf("Unspported: segacd_main_dataram_part1_w (word RAM) in mode 1\n");
+			// wordram accees
+		}
+		else
+		{
+			printf("Unspported: segacd_main_dataram_part1_w (Cell rearranged RAM) in mode 1 (illega?)\n"); // is this legal??
+		}		
 	}
 }
 
@@ -4985,7 +5037,7 @@ static READ16_HANDLER( segacd_sub_dataram_part1_r )
 	}
 	else if (segacd_ram_mode==1)
 	{
-		printf("Unspported: segacd_sub_dataram_part1_r in mode 1\n");
+		printf("Unspported: segacd_sub_dataram_part1_r in mode 1 (Word RAM Expander - 1 Byte Per Pixel)\n");
 		return 0x0000;
 	}
 
@@ -5009,7 +5061,7 @@ static WRITE16_HANDLER( segacd_sub_dataram_part1_w )
 	}
 	else if (segacd_ram_mode==1)
 	{
-		printf("Unspported: segacd_sub_dataram_part1_w in mode 1\n");
+		printf("Unspported: segacd_sub_dataram_part1_w in mode 1 (Word RAM Expander - 1 Byte Per Pixel)\n");
 	}
 }
 
@@ -5017,12 +5069,12 @@ static READ16_HANDLER( segacd_sub_dataram_part2_r )
 {
 	if (segacd_ram_mode==0)
 	{
-		printf("ILLEGAL segacd_sub_dataram_part2_r in mode 1\n");
+		printf("ILLEGAL segacd_sub_dataram_part2_r in mode 0\n"); // not mapepd to anything in mode 0
 		return 0x0000;
 	}
 	else if (segacd_ram_mode==1)
 	{
-		printf("Unspported: segacd_sub_dataram_part2_r in mode 1\n");
+		printf("Unspported: segacd_sub_dataram_part2_r in mode 1 (Word RAM)\n");
 		return 0x0000;
 	}
 
@@ -5033,11 +5085,11 @@ static WRITE16_HANDLER( segacd_sub_dataram_part2_w )
 {
 	if (segacd_ram_mode==0)
 	{
-		printf("ILLEGAL segacd_sub_dataram_part2_w in mode 1\n");
+		printf("ILLEGAL segacd_sub_dataram_part2_w in mode 0\n"); // not mapepd to anything in mode 0
 	}
 	else if (segacd_ram_mode==1)
 	{
-		printf("Unsupported: segacd_sub_dataram_part2_w in mode 1\n");
+		printf("Unsupported: segacd_sub_dataram_part2_w in mode 1 (Word RAM)\n");
 	}
 }
 
@@ -5572,7 +5624,10 @@ static ADDRESS_MAP_START( segacd_map, ADDRESS_SPACE_PROGRAM, 16 )
 
 	AM_RANGE(0xfe0000, 0xfe3fff) AM_RAM // backup RAM, odd bytes only!
 
-	AM_RANGE(0xff0000, 0xff7fff) AM_RAM // PCM, RF5C164
+	AM_RANGE(0xff0000, 0xff001f) AM_DEVWRITE8("rfsnd", rf5c68_w, 0x00ff)  // PCM, RF5C164
+	AM_RANGE(0xff2000, 0xff3fff) AM_DEVREADWRITE8("rfsnd", rf5c68_mem_r, rf5c68_mem_w,0x00ff)  // PCM, RF5C164
+	
+	 
 	AM_RANGE(0xff8000 ,0xff8001) AM_READWRITE(segacd_sub_led_ready_r, segacd_sub_led_ready_w)
 	AM_RANGE(0xff8002 ,0xff8003) AM_READWRITE(segacd_sub_memory_mode_r, segacd_sub_memory_mode_w)
 
@@ -8542,6 +8597,10 @@ MACHINE_CONFIG_DERIVED( genesis_scd, megadriv )
 	MDRV_SOUND_ROUTE( 0, "lspeaker", 1.00 )
 	MDRV_SOUND_ROUTE( 1, "rspeaker", 1.00 )
 
+	MDRV_SOUND_ADD("rfsnd", RF5C68, SEGACD_CLOCK) // RF5C164!
+	MDRV_SOUND_ROUTE( 0, "lspeaker", 0.25 )
+	MDRV_SOUND_ROUTE( 1, "rspeaker", 0.25 )
+
 	#ifdef MESS
 	MDRV_CDROM_ADD( "cdrom" )
 	#endif
@@ -8556,6 +8615,10 @@ MACHINE_CONFIG_DERIVED( genesis_32x_scd, genesis_32x )
 	MDRV_SOUND_ROUTE( 0, "lspeaker", 1.00 )
 	MDRV_SOUND_ROUTE( 1, "rspeaker", 1.00 )
 
+	MDRV_SOUND_ADD("rfsnd", RF5C68, SEGACD_CLOCK) // RF5C164
+	MDRV_SOUND_ROUTE( 0, "lspeaker", 0.25 )
+	MDRV_SOUND_ROUTE( 1, "rspeaker", 0.25 )
+
 	#ifdef MESS
 	MDRV_CDROM_ADD( "cdrom" )
 	#endif