Don't take MD+ capable carts for a real SegaCD

marshw.c

@@ -251,10 +251,9 @@ void Mars_Init(void)
 
 	Mars_UpdateCD();
 
-	if (mars_cd_ok && !(mars_cd_ok & 0x2))
+	if (mars_cd_ok & 0x1)
 	{
-		/* if the CD is present and it's */
-		/* not an MD+, give it seconds to init */
+		/* if the CD is present, give it seconds to init */
 		Mars_WaitTicks(180);
 	}
 }

marssound.c

@@ -116,7 +116,7 @@ void S_Init(void)
 		sfxchannels[i].data = NULL;
 
 	// check if CD is available, reset the driver option if not
-	mcd_avail = S_CDAvailable();
+	mcd_avail = S_CDAvailable() & 0x1;
 	if (!mcd_avail && sfxdriver > 1)
 		sfxdriver = 0;
 

o_main.c

@@ -140,6 +140,8 @@ void O_DrawControl(void)
 
 void O_Init (void)
 {
+	int cd_avail;
+
 /* cache all needed graphics */
 	o_cursor1 = W_CheckNumForName("M_SKULL1");
 	o_cursor2 = W_CheckNumForName("M_SKULL2");
@@ -254,10 +256,13 @@ void O_Init (void)
 	D_memcpy(menuscreen[ms_audio].name, "Audio", 7);
 	menuscreen[ms_audio].firstitem = mi_soundvol;
 	menuscreen[ms_audio].numitems = mi_music - mi_soundvol + 1;
-	if (S_CDAvailable()) /* MD+ */
+
+	cd_avail = S_CDAvailable();
+	if (cd_avail) /* CDA or MD+ */
 	{
 		menuscreen[ms_audio].numitems++;
-		menuscreen[ms_audio].numitems++;
+		if (cd_avail & 0x1) /* CD, not MD+ */
+			menuscreen[ms_audio].numitems++;
 	}
 
 	D_memcpy(menuscreen[ms_video].name, "Video", 7);
@@ -572,7 +577,7 @@ void O_Control (player_t *player)
 					case mi_music:
 						if (++o_musictype > mustype_cd)
 							o_musictype = mustype_cd;
-						if (o_musictype == mustype_cd && !S_CDAvailable())
+						if (o_musictype == mustype_cd)
 							o_musictype = mustype_fm;
 						break;
 					case mi_sfxdriver:

src-md/crt0.s

@@ -913,6 +913,7 @@ read_cdstate:
         move.w  megasd_num_cdtracks,d0
         lsl.l   #2,d0
         or.w    megasd_ok,d0
+        or.w    cd_ok,d0
 
         move.w  d0,0xA15122
         move.w  #0,0xA15120         /* done */

src-md/main.c

@@ -120,7 +120,7 @@ uint16_t InitCD(void)
 
     scd_init_pcm();
 
-    return 1; // CD ready to go!
+    return 0x1; // CD ready to go!
 }
 
 int main(void)

src-md/megasd.c

@@ -61,7 +61,7 @@ static uint16_t ProtectedInitMegaSD(void)
 		MEGASD_CTRL_PORT = MEGASD_CMD_GET_NUMTRKS;
 		MEGASD_WAIT_CMD_RSLT(timeout);
 		megasd_num_cdtracks = MEGASD_RSLT_PORT;
-		return 0x0003; // MD+, CD OK
+		return 0x0002; // MD+, CD OK
 	}
 
 #undef MEGASD_WAIT_CMD_RSLT