clean up dac code a bit

[picodrive.git] / pico / sms.c

diff --git a/pico/sms.c b/pico/sms.c
index e94e731..7dc796e 100644 (file)
--- a/pico/sms.c
+++ b/pico/sms.c
@@ -1,10 +1,16 @@
+/*
+ * SMS emulation
+ * (C) notaz, 2009-2010
+ *
+ * This work is licensed under the terms of MAME license.
+ * See COPYING file in the top-level directory.
+ */
 /*
  * TODO:
  * - start in a state as if BIOS ran
  * - remaining status flags (OVR/COL)
  * - RAM support in mapper
  * - region support
- * - Pause button (NMI)
  * - SN76496 DAC-like usage
  * - H counter
  */
@@ -103,7 +109,7 @@ static unsigned char z80_sms_in(unsigned short a)
       break;
 
     case 0xc1: /* I/O port B and miscellaneous */
-      d = (Pico.sms_io_ctl & 0x80) | ((Pico.sms_io_ctl << 1) & 0x40) | 0x30;
+      d = (Pico.ms.io_ctl & 0x80) | ((Pico.ms.io_ctl << 1) & 0x40) | 0x30;
       d |= ~(PicoPad[1] >> 2) & 0x0f;
       break;
   }
@@ -119,7 +125,7 @@ static void z80_sms_out(unsigned short a, unsigned char d)
   switch (a)
   {
     case 0x01:
-      Pico.sms_io_ctl = d;
+      Pico.ms.io_ctl = d;
       break;
 
     case 0x40:
@@ -167,6 +173,7 @@ static void write_bank(unsigned short a, unsigned char d)
 #endif
       break;
   }
+  Pico.ms.carthw[a & 0x0f] = d;
 }
 
 static void xwrite(unsigned int a, unsigned char d)
@@ -174,7 +181,7 @@ static void xwrite(unsigned int a, unsigned char d)
   elprintf(EL_IO, "z80 write [%04x] %02x", a, d);
   if (a >= 0xc000)
     Pico.zram[a & 0x1fff] = d;
-  if (a >= 0xfff0)
+  if (a >= 0xfff8)
     write_bank(a, d);
 }
 
@@ -203,6 +210,9 @@ void PicoPowerMS(void)
   tmp = 1 << s;
   bank_mask = (tmp - 1) >> 14;
 
+  Pico.ms.carthw[0x0e] = 1;
+  Pico.ms.carthw[0x0f] = 2;
+
   PicoReset();
 }
 
@@ -229,6 +239,12 @@ void PicoMemSetupMS(void)
 #endif
 }
 
+void PicoStateLoadedMS(void)
+{
+  write_bank(0xfffe, Pico.ms.carthw[0x0e]);
+  write_bank(0xffff, Pico.ms.carthw[0x0f]);
+}
+
 void PicoFrameMS(void)
 {
   struct PicoVideo *pv = &Pico.video;
@@ -239,14 +255,24 @@ void PicoFrameMS(void)
   int skip = PicoSkipFrame;
   int lines_vis = 192;
   int hint; // Hint counter
+  int nmi;
   int y;
 
+  PsndStartFrame();
+
+  nmi = (PicoPad[0] >> 7) & 1;
+  if (!Pico.ms.nmi_state && nmi)
+    z80_nmi();
+  Pico.ms.nmi_state = nmi;
+
   PicoFrameStartMode4();
   hint = pv->reg[0x0a];
 
   for (y = 0; y < lines; y++)
   {
     pv->v_counter = Pico.m.scanline = y;
+    if (y > 218)
+      pv->v_counter = y - 6;
 
     if (y < lines_vis && !skip)
       PicoLineMode4(y);