sms: improve irq handling

[picodrive.git] / pico / sms.c

diff --git a/pico/sms.c b/pico/sms.c
index 748c326..286b8bf 100644 (file)
--- a/pico/sms.c
+++ b/pico/sms.c
@@ -8,10 +8,8 @@
 /*
  * TODO:
  * - start in a state as if BIOS ran
- * - remaining status flags (OVR/COL)
  * - RAM support in mapper
  * - region support
- * - SN76496 DAC-like usage
  * - H counter
  */
 #include "pico_int.h"
@@ -34,6 +32,7 @@ static unsigned char vdp_ctl_read(void)
   struct PicoVideo *pv = &Pico.video;
   unsigned char d;
 
+  z80_int_assert(0);
   d = pv->status | (pv->pending_ints << 7);
   pv->pending = pv->pending_ints = 0;
   pv->status = 0;
@@ -57,14 +56,34 @@ static void vdp_data_write(unsigned char d)
   pv->pending = 0;
 }
 
-static void vdp_ctl_write(unsigned char d)
+static NOINLINE void vdp_reg_write(struct PicoVideo *pv, u8 a, u8 d)
+{
+  int l;
+
+  pv->reg[a] = d;
+  switch (a) {
+  case 0:
+    l = pv->pending_ints & (d >> 3) & 2;
+    elprintf(EL_INTS, "hint %d", l);
+    z80_int_assert(l);
+    break;
+  case 1:
+    l = pv->pending_ints & (d >> 5) & 1;
+    elprintf(EL_INTS, "vint %d", l);
+    z80_int_assert(l);
+    break;
+  }
+}
+
+static void vdp_ctl_write(u8 d)
 {
   struct PicoVideo *pv = &Pico.video;
 
   if (pv->pending) {
     if ((d >> 6) == 2) {
-      pv->reg[d & 0x0f] = pv->addr;
       elprintf(EL_IO, "  VDP r%02x=%02x", d & 0x0f, pv->addr & 0xff);
+      if (pv->reg[d & 0x0f] != (u8)pv->addr)
+        vdp_reg_write(pv, d & 0x0f, pv->addr);
     }
     pv->type = d >> 6;
     pv->addr &= 0x00ff;
@@ -133,8 +152,9 @@ static void z80_sms_out(unsigned short a, unsigned char d)
 
     case 0x40:
     case 0x41:
-      if (PicoIn.opt & POPT_EN_PSG)
-        SN76496Write(d);
+      if ((d & 0x90) == 0x90 && Pico.snd.psg_line < Pico.m.scanline)
+        PsndDoPSG(Pico.m.scanline);
+      SN76496Write(d);
       break;
 
     case 0x80:
@@ -288,7 +308,7 @@ void PicoFrameMS(void)
         pv->pending_ints |= 2;
         if (pv->reg[0] & 0x10) {
           elprintf(EL_INTS, "hint");
-          z80_int();
+          z80_int_assert(1);
         }
       }
     }
@@ -296,16 +316,20 @@ void PicoFrameMS(void)
       pv->pending_ints |= 1;
       if (pv->reg[1] & 0x20) {
         elprintf(EL_INTS, "vint");
-        z80_int();
+        z80_int_assert(1);
       }
     }
 
+    // 224 because of how it's done for MD...
+    if (y == 224 && PicoIn.sndOut)
+      PsndGetSamplesMS();
+
     cycles_aim += cycles_line;
     cycles_done += z80_run((cycles_aim - cycles_done) >> 8) << 8;
   }
 
-  if (PsndOut)
-    PsndGetSamplesMS();
+  if (PicoIn.sndOut && Pico.snd.psg_line < lines)
+    PsndDoPSG(lines - 1);
 }
 
 void PicoFrameDrawOnlyMS(void)
@@ -319,3 +343,4 @@ void PicoFrameDrawOnlyMS(void)
     PicoLineMode4(y);
 }
 
+// vim:ts=2:sw=2:expandtab