X-Git-Url: https://notaz.gp2x.de/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=Pico%2Fcd%2FMemory.c;h=71ec377be0ce7ce70b670fe31ed007ed535e1a3e;hb=eff55556cff77fd64cff4be32e449e0a58aed6fe;hp=0b11e98c24ad080e379383e266eebb48903c3c40;hpb=a40308010482ca8674bb6ff8c7cf271098f2aebe;p=picodrive.git

diff --git a/Pico/cd/Memory.c b/Pico/cd/Memory.c
index 0b11e98..71ec377 100644
--- a/Pico/cd/Memory.c
+++ b/Pico/cd/Memory.c
@@ -1,10 +1,6 @@
-// This is part of Pico Library
-
-// (c) Copyright 2004 Dave, All rights reserved.
-// (c) Copyright 2007 notaz, All rights reserved.
-// Free for non-commercial use.
-
-// For commercial use, separate licencing terms must be obtained.
+// Memory I/O handlers for Sega/Mega CD.
+// Loosely based on Gens code.
+// (c) Copyright 2007, Grazvydas "notaz" Ignotas
 
 // A68K no longer supported here
 
@@ -12,27 +8,37 @@
 
 #include "../PicoInt.h"
 
-#include "../sound/sound.h"
 #include "../sound/ym2612.h"
 #include "../sound/sn76496.h"
 
 #include "gfx_cd.h"
 #include "pcm.h"
 
+#ifndef UTYPES_DEFINED
 typedef unsigned char  u8;
 typedef unsigned short u16;
 typedef unsigned int   u32;
+#define UTYPES_DEFINED
+#endif
 
 //#define __debug_io
 //#define __debug_io2
 
-//#define rdprintf dprintf
-#define rdprintf(...)
+#define rdprintf dprintf
+//#define rdprintf(...)
 //#define wrdprintf dprintf
 #define wrdprintf(...)
+#define plprintf dprintf
+//#define plprintf(...)
 
 // -----------------------------------------------------------------
 
+// poller detection
+//#undef USE_POLL_DETECT
+#define POLL_LIMIT 16
+#define POLL_CYCLES 124
+// int m68k_poll_addr, m68k_poll_cnt;
+unsigned int s68k_poll_adclk, s68k_poll_cnt;
 
 #ifndef _ASM_CD_MEMORY_C
 static u32 m68k_reg_read16(u32 a)
@@ -47,7 +53,9 @@ static u32 m68k_reg_read16(u32 a)
       goto end;
     case 2:
       d = (Pico_mcd->s68k_regs[a]<<8) | (Pico_mcd->s68k_regs[a+1]&0xc7);
-      dprintf("m68k_regs r3: %02x @%06x", (u8)d, SekPcS68k);
+      // the DMNA delay must only be visible on s68k side (Lunar2, Silpheed)
+      if (Pico_mcd->m.state_flags&2) { d &= ~1; d |= 2; }
+      //printf("m68k_regs r3: %02x @%06x\n", (u8)d, SekPc);
       goto end;
     case 4:
       d = Pico_mcd->s68k_regs[4]<<8;
@@ -108,11 +116,12 @@ void m68k_reg_write8(u32 a, u32 d)
       Pico_mcd->m.busreq = d;
       return;
     case 2:
+      dprintf("m68k: prg wp=%02x", d);
       Pico_mcd->s68k_regs[2] = d; // really use s68k side register
       return;
     case 3: {
       u32 dold = Pico_mcd->s68k_regs[3]&0x1f;
-      dprintf("m68k_regs w3: %02x @%06x", (u8)d, SekPc);
+      //printf("m68k_regs w3: %02x @%06x\n", (u8)d, SekPc);
       d &= 0xc2;
       if ((dold>>6) != ((d>>6)&3))
         dprintf("m68k: prg bank: %i -> %i", (Pico_mcd->s68k_regs[a]>>6), ((d>>6)&3));
@@ -123,15 +132,22 @@ void m68k_reg_write8(u32 a, u32 d)
         d ^= 2;                // writing 0 to DMNA actually sets it, 1 does nothing
       } else {
         //dold &= ~2; // ??
+#if 1
+	if ((d & 2) && !(dold & 2)) {
+          Pico_mcd->m.state_flags |= 2; // we must delay setting DMNA bit (needed for Silpheed)
+          d &= ~2;
+	}
+#else
         if (d & 2) dold &= ~1; // return word RAM to s68k in 2M mode
+#endif
       }
       Pico_mcd->s68k_regs[3] = d | dold; // really use s68k side register
-
-/*
-     d |= Pico_mcd->s68k_regs[3]&0x1d;
-     if (!(d & 4) && (d & 2)) d &= ~1; // return word RAM to s68k in 2M mode
-     Pico_mcd->s68k_regs[3] = d; // really use s68k side register
-*/
+#ifdef USE_POLL_DETECT
+      if ((s68k_poll_adclk&0xfe) == 2 && s68k_poll_cnt > POLL_LIMIT) {
+        SekSetStopS68k(0); s68k_poll_adclk = 0;
+        plprintf("s68k poll release, a=%02x\n", a);
+      }
+#endif
       return;
     }
     case 6:
@@ -141,20 +157,59 @@ void m68k_reg_write8(u32 a, u32 d)
       Pico_mcd->bios[0x72] = d;
       dprintf("hint vector set to %08x", PicoRead32(0x70));
       return;
+    case 0xf:
+      d = (d << 1) | ((d >> 7) & 1); // rol8 1 (special case)
     case 0xe:
       //dprintf("m68k: comm flag: %02x", d);
       Pico_mcd->s68k_regs[0xe] = d;
+#ifdef USE_POLL_DETECT
+      if ((s68k_poll_adclk&0xfe) == 0xe && s68k_poll_cnt > POLL_LIMIT) {
+        SekSetStopS68k(0); s68k_poll_adclk = 0;
+        plprintf("s68k poll release, a=%02x\n", a);
+      }
+#endif
       return;
   }
 
   if ((a&0xf0) == 0x10) {
       Pico_mcd->s68k_regs[a] = d;
+#ifdef USE_POLL_DETECT
+      if ((a&0xfe) == (s68k_poll_adclk&0xfe) && s68k_poll_cnt > POLL_LIMIT) {
+        SekSetStopS68k(0); s68k_poll_adclk = 0;
+        plprintf("s68k poll release, a=%02x\n", a);
+      }
+#endif
       return;
   }
 
   dprintf("m68k FIXME: invalid write? [%02x] %02x", a, d);
 }
 
+#ifndef _ASM_CD_MEMORY_C
+static
+#endif
+u32 s68k_poll_detect(u32 a, u32 d)
+{
+#ifdef USE_POLL_DETECT
+  // polling detection
+  if (a == (s68k_poll_adclk&0xff)) {
+    unsigned int clkdiff = SekCyclesDoneS68k() - (s68k_poll_adclk>>8);
+    if (clkdiff <= POLL_CYCLES) {
+      s68k_poll_cnt++;
+      //printf("-- diff: %u, cnt = %i\n", clkdiff, s68k_poll_cnt);
+      if (s68k_poll_cnt > POLL_LIMIT) {
+        SekSetStopS68k(1);
+        plprintf("s68k poll detected @ %06x, a=%02x\n", SekPcS68k, a);
+      }
+      s68k_poll_adclk = (SekCyclesDoneS68k() << 8) | a;
+      return d;
+    }
+  }
+  s68k_poll_adclk = (SekCyclesDoneS68k() << 8) | a;
+  s68k_poll_cnt = 0;
+#endif
+  return d;
+}
 
 #define READ_FONT_DATA(basemask) \
 { \
@@ -178,47 +233,42 @@ u32 s68k_reg_read16(u32 a)
 
   switch (a) {
     case 0:
-      d = ((Pico_mcd->s68k_regs[0]&3)<<8) | 1; // ver = 0, not in reset state
-      goto end;
+      return ((Pico_mcd->s68k_regs[0]&3)<<8) | 1; // ver = 0, not in reset state
     case 2:
-      d = (Pico_mcd->s68k_regs[a]<<8) | (Pico_mcd->s68k_regs[a+1]&0x1f);
-      dprintf("s68k_regs r3: %02x @%06x", (u8)d, SekPcS68k);
-      goto end;
+      d = (Pico_mcd->s68k_regs[2]<<8) | (Pico_mcd->s68k_regs[3]&0x1f);
+      //printf("s68k_regs r3: %02x @%06x\n", (u8)d, SekPcS68k);
+      return s68k_poll_detect(a, d);
     case 6:
-      d = CDC_Read_Reg();
-      goto end;
+      return CDC_Read_Reg();
     case 8:
-      d = Read_CDC_Host(1); // Gens returns 0 here on byte reads
-      goto end;
+      return Read_CDC_Host(1); // Gens returns 0 here on byte reads
     case 0xC:
       d = Pico_mcd->m.timer_stopwatch >> 16;
       dprintf("s68k stopwatch timer read (%04x)", d);
-      goto end;
+      return d;
     case 0x30:
-      dprintf("s68k int3 timer read (%02x%02x)", Pico_mcd->s68k_regs[30], Pico_mcd->s68k_regs[31]);
-      break;
+      dprintf("s68k int3 timer read (%02x)", Pico_mcd->s68k_regs[31]);
+      return Pico_mcd->s68k_regs[31];
     case 0x34: // fader
-      d = 0; // no busy bit
-      goto end;
+      return 0; // no busy bit
     case 0x50: // font data (check: Lunar 2, Silpheed)
       READ_FONT_DATA(0x00100000);
-      goto end;
+      return d;
     case 0x52:
       READ_FONT_DATA(0x00010000);
-      goto end;
+      return d;
     case 0x54:
       READ_FONT_DATA(0x10000000);
-      goto end;
+      return d;
     case 0x56:
       READ_FONT_DATA(0x01000000);
-      goto end;
+      return d;
   }
 
   d = (Pico_mcd->s68k_regs[a]<<8) | Pico_mcd->s68k_regs[a+1];
 
-end:
-
-  // dprintf("ret = %04x", d);
+  if (a >= 0x0e && a < 0x30)
+    return s68k_poll_detect(a, d);
 
   return d;
 }
@@ -237,7 +287,7 @@ void s68k_reg_write8(u32 a, u32 d)
       return; // only m68k can change WP
     case 3: {
       int dold = Pico_mcd->s68k_regs[3];
-      dprintf("s68k_regs w3: %02x @%06x", (u8)d, SekPc);
+      //printf("s68k_regs w3: %02x @%06x\n", (u8)d, SekPcS68k);
       d &= 0x1d;
       d |= dold&0xc2;
       if (d&4) {
@@ -292,8 +342,7 @@ void s68k_reg_write8(u32 a, u32 d)
       Pico_mcd->m.timer_stopwatch = 0;
       return;
     case 0xe:
-      Pico_mcd->s68k_regs[0Xf] = (d>>1) | (d<<7); // ror8, Gens note: Dragons lair
-      Pico_mcd->m.timer_stopwatch = 0;
+      Pico_mcd->s68k_regs[0xf] = (d>>1) | (d<<7); // ror8 1, Gens note: Dragons lair
       return;
     case 0x31:
       dprintf("s68k set int3 timer: %02x", d);
@@ -355,7 +404,7 @@ static void OtherWrite8End(u32 a, u32 d, int realsize)
 {
   if ((a&0xffffc0)==0xa12000) { m68k_reg_write8(a, d); return; }
 
-  dprintf("m68k FIXME: strange w%i: %06x, %08x @%06x", realsize, a&0xffffff, d, SekPc);
+  dprintf("m68k FIXME: strange w%i: [%06x], %08x @%06x", realsize, a&0xffffff, d, SekPc);
 }
 
 
@@ -364,14 +413,15 @@ static void OtherWrite8End(u32 a, u32 d, int realsize)
 #include "cell_map.c"
 #endif // !def _ASM_CD_MEMORY_C
 
+
 // -----------------------------------------------------------------
 //                     Read Rom and read Ram
 
 //u8 PicoReadM68k8_(u32 a);
 #ifdef _ASM_CD_MEMORY_C
-u8 PicoReadM68k8(u32 a);
+u32 PicoReadM68k8(u32 a);
 #else
-static u8 PicoReadM68k8(u32 a)
+static u32 PicoReadM68k8(u32 a)
 {
   u32 d=0;
 
@@ -382,7 +432,7 @@ static u8 PicoReadM68k8(u32 a)
   if (a < 0x20000) { d = *(u8 *)(Pico_mcd->bios+(a^1)); goto end; } // bios
 
   // prg RAM
-  if ((a&0xfe0000)==0x020000 && (Pico_mcd->m.busreq&2)) {
+  if ((a&0xfe0000)==0x020000 && (Pico_mcd->m.busreq&3)!=1) {
     u8 *prg_bank = Pico_mcd->prg_ram_b[Pico_mcd->s68k_regs[3]>>6];
     d = *(prg_bank+((a^1)&0x1ffff));
     goto end;
@@ -420,17 +470,17 @@ static u8 PicoReadM68k8(u32 a)
 #ifdef __debug_io
   dprintf("r8 : %06x,   %02x @%06x", a&0xffffff, (u8)d, SekPc);
 #endif
-  return (u8)d;
+  return d;
 }
 #endif
 
 
 #ifdef _ASM_CD_MEMORY_C
-u16 PicoReadM68k16(u32 a);
+u32 PicoReadM68k16(u32 a);
 #else
-static u16 PicoReadM68k16(u32 a)
+static u32 PicoReadM68k16(u32 a)
 {
-  u16 d=0;
+  u32 d=0;
 
   if ((a&0xe00000)==0xe00000) { d=*(u16 *)(Pico.ram+(a&0xfffe)); goto end; } // Ram
 
@@ -439,9 +489,11 @@ static u16 PicoReadM68k16(u32 a)
   if (a < 0x20000) { d = *(u16 *)(Pico_mcd->bios+a); goto end; } // bios
 
   // prg RAM
-  if ((a&0xfe0000)==0x020000 && (Pico_mcd->m.busreq&2)) {
+  if ((a&0xfe0000)==0x020000 && (Pico_mcd->m.busreq&3)!=1) {
     u8 *prg_bank = Pico_mcd->prg_ram_b[Pico_mcd->s68k_regs[3]>>6];
+    wrdprintf("m68k_prgram r16: [%i,%06x] @%06x", Pico_mcd->s68k_regs[3]>>6, a, SekPc);
     d = *(u16 *)(prg_bank+(a&0x1fffe));
+    wrdprintf("ret = %04x", d);
     goto end;
   }
 
@@ -465,7 +517,7 @@ static u16 PicoReadM68k16(u32 a)
   if ((a&0xffffc0)==0xa12000)
     rdprintf("m68k_regs r16: [%02x] @%06x", a&0x3f, SekPc);
 
-  d = (u16)OtherRead16(a, 16);
+  d = OtherRead16(a, 16);
 
   if ((a&0xffffc0)==0xa12000)
     rdprintf("ret = %04x", d);
@@ -494,7 +546,7 @@ static u32 PicoReadM68k32(u32 a)
   if (a < 0x20000) { u16 *pm=(u16 *)(Pico_mcd->bios+a); d = (pm[0]<<16)|pm[1]; goto end; } // bios
 
   // prg RAM
-  if ((a&0xfe0000)==0x020000 && (Pico_mcd->m.busreq&2)) {
+  if ((a&0xfe0000)==0x020000 && (Pico_mcd->m.busreq&3)!=1) {
     u8 *prg_bank = Pico_mcd->prg_ram_b[Pico_mcd->s68k_regs[3]>>6];
     u16 *pm=(u16 *)(prg_bank+(a&0x1fffe));
     d = (pm[0]<<16)|pm[1];
@@ -542,7 +594,6 @@ static u32 PicoReadM68k32(u32 a)
 
 
 // -----------------------------------------------------------------
-//                            Write Ram
 
 #ifdef _ASM_CD_MEMORY_C
 void PicoWriteM68k8(u32 a,u8 d);
@@ -564,7 +615,7 @@ static void PicoWriteM68k8(u32 a,u8 d)
   a&=0xffffff;
 
   // prg RAM
-  if ((a&0xfe0000)==0x020000 && (Pico_mcd->m.busreq&2)) {
+  if ((a&0xfe0000)==0x020000 && (Pico_mcd->m.busreq&3)!=1) {
     u8 *prg_bank = Pico_mcd->prg_ram_b[Pico_mcd->s68k_regs[3]>>6];
     *(u8 *)(prg_bank+((a^1)&0x1ffff))=d;
     return;
@@ -586,8 +637,11 @@ static void PicoWriteM68k8(u32 a,u8 d)
     return;
   }
 
-  if ((a&0xffffc0)==0xa12000)
+  if ((a&0xffffc0)==0xa12000) {
     rdprintf("m68k_regs w8: [%02x] %02x @%06x", a&0x3f, d, SekPc);
+    m68k_reg_write8(a, d);
+    return;
+  }
 
   OtherWrite8(a,d,8);
 }
@@ -612,8 +666,9 @@ static void PicoWriteM68k16(u32 a,u16 d)
   a&=0xfffffe;
 
   // prg RAM
-  if ((a&0xfe0000)==0x020000 && (Pico_mcd->m.busreq&2)) {
+  if ((a&0xfe0000)==0x020000 && (Pico_mcd->m.busreq&3)!=1) {
     u8 *prg_bank = Pico_mcd->prg_ram_b[Pico_mcd->s68k_regs[3]>>6];
+    wrdprintf("m68k_prgram w16: [%i,%06x] %04x @%06x", Pico_mcd->s68k_regs[3]>>6, a, d, SekPc);
     *(u16 *)(prg_bank+(a&0x1fffe))=d;
     return;
   }
@@ -634,8 +689,23 @@ static void PicoWriteM68k16(u32 a,u16 d)
     return;
   }
 
-  if ((a&0xffffc0)==0xa12000)
+  // regs
+  if ((a&0xffffc0)==0xa12000) {
     rdprintf("m68k_regs w16: [%02x] %04x @%06x", a&0x3f, d, SekPc);
+    if (a == 0xe) { // special case, 2 byte writes would be handled differently
+      Pico_mcd->s68k_regs[0xe] = d >> 8;
+#ifdef USE_POLL_DETECT
+      if ((s68k_poll_adclk&0xfe) == 0xe && s68k_poll_cnt > POLL_LIMIT) {
+        SekSetStopS68k(0); s68k_poll_adclk = 0;
+        plprintf("s68k poll release, a=%02x\n", a);
+      }
+#endif
+      return;
+    }
+    m68k_reg_write8(a,  d>>8);
+    m68k_reg_write8(a+1,d&0xff);
+    return;
+  }
 
   OtherWrite16(a,d);
 }
@@ -662,7 +732,7 @@ static void PicoWriteM68k32(u32 a,u32 d)
   a&=0xfffffe;
 
   // prg RAM
-  if ((a&0xfe0000)==0x020000 && (Pico_mcd->m.busreq&2)) {
+  if ((a&0xfe0000)==0x020000 && (Pico_mcd->m.busreq&3)!=1) {
     u8 *prg_bank = Pico_mcd->prg_ram_b[Pico_mcd->s68k_regs[3]>>6];
     u16 *pm=(u16 *)(prg_bank+(a&0x1fffe));
     pm[0]=(u16)(d>>16); pm[1]=(u16)d;
@@ -694,8 +764,10 @@ static void PicoWriteM68k32(u32 a,u32 d)
     return;
   }
 
-  if ((a&0xffffc0)==0xa12000)
+  if ((a&0xffffc0)==0xa12000) {
     rdprintf("m68k_regs w32: [%02x] %08x @%06x", a&0x3f, d, SekPc);
+    if ((a&0x3e) == 0xe) dprintf("m68k FIXME: w32 [%02x]", a&0x3f);
+  }
 
   OtherWrite16(a,  (u16)(d>>16));
   OtherWrite16(a+2,(u16)d);
@@ -703,12 +775,14 @@ static void PicoWriteM68k32(u32 a,u32 d)
 #endif
 
 
+// -----------------------------------------------------------------
+//                            S68k
 // -----------------------------------------------------------------
 
 #ifdef _ASM_CD_MEMORY_C
-u8 PicoReadS68k8(u32 a);
+u32 PicoReadS68k8(u32 a);
 #else
-static u8 PicoReadS68k8(u32 a)
+static u32 PicoReadS68k8(u32 a)
 {
   u32 d=0;
 
@@ -724,7 +798,13 @@ static u8 PicoReadS68k8(u32 a)
   if ((a&0xfffe00) == 0xff8000) {
     a &= 0x1ff;
     rdprintf("s68k_regs r8: [%02x] @ %06x", a, SekPcS68k);
-    if (a >= 0x58 && a < 0x68)
+    if (a >= 0x0e && a < 0x30) {
+      d = Pico_mcd->s68k_regs[a];
+      s68k_poll_detect(a, d);
+      rdprintf("ret = %02x", (u8)d);
+      goto end;
+    }
+    else if (a >= 0x58 && a < 0x68)
          d = gfx_cd_read(a&~1);
     else d = s68k_reg_read16(a&~1);
     if ((a&1)==0) d>>=8;
@@ -790,16 +870,15 @@ static u8 PicoReadS68k8(u32 a)
 #ifdef __debug_io2
   dprintf("s68k r8 : %06x,   %02x @%06x", a&0xffffff, (u8)d, SekPcS68k);
 #endif
-  return (u8)d;
+  return d;
 }
 #endif
 
 
-//u16 PicoReadS68k16_(u32 a);
 #ifdef _ASM_CD_MEMORY_C
-u16 PicoReadS68k16(u32 a);
+u32 PicoReadS68k16(u32 a);
 #else
-static u16 PicoReadS68k16(u32 a)
+static u32 PicoReadS68k16(u32 a)
 {
   u32 d=0;
 
@@ -807,7 +886,9 @@ static u16 PicoReadS68k16(u32 a)
 
   // prg RAM
   if (a < 0x80000) {
+    wrdprintf("s68k_prgram r16: [%06x] @%06x", a, SekPcS68k);
     d = *(u16 *)(Pico_mcd->prg_ram+a);
+    wrdprintf("ret = %04x", d);
     goto end;
   }
 
@@ -923,7 +1004,6 @@ static u32 PicoReadS68k32(u32 a)
       d  = Pico_mcd->word_ram1M[bank][((a+0)^1)&0x1ffff] << 16;
       d |= Pico_mcd->word_ram1M[bank][((a+1)^1)&0x1ffff];
       d |= d << 4; d &= 0x0f0f0f0f;
-      dprintf("FIXME: decode");
     } else {
       // allow access in any mode, like Gens does
       u16 *pm=(u16 *)(Pico_mcd->word_ram2M+(a&0x3fffe)); d = (pm[0]<<16)|pm[1];
@@ -946,7 +1026,7 @@ static u32 PicoReadS68k32(u32 a)
 
   // PCM
   if ((a&0xff8000)==0xff0000) {
-    dprintf("FIXME: s68k_pcm r32: [%06x] @%06x", a, SekPcS68k);
+    dprintf("s68k_pcm r32: [%06x] @%06x", a, SekPcS68k);
     a &= 0x7fff;
     if (a >= 0x2000) {
       a >>= 1;
@@ -1002,8 +1082,6 @@ static void decode_write8(u32 a, u8 d, int r3)
   d  &= 0x0f;
   if (!(a&1)) d <<= 4;
 
-  //dprintf("FIXME: decode, r3 = %02x", r3);
-
   if (r3 == 8) {
     if ((!(*pd & (~oldmask))) && d) goto do_it;
   } else if (r3 > 8) {
@@ -1041,15 +1119,11 @@ static void decode_write16(u32 a, u16 d, int r3)
   } else {
     *pd = d;
   }
-
-  //dprintf("FIXME: decode");
 }
 #endif
 
 // -----------------------------------------------------------------
 
-//void PicoWriteS68k8_(u32 a,u8 d);
-//void PicoWriteS68k8__(u32 a,u8 d);
 #ifdef _ASM_CD_MEMORY_C
 void PicoWriteS68k8(u32 a,u8 d);
 #else
@@ -1060,21 +1134,11 @@ static void PicoWriteS68k8(u32 a,u8 d)
 #endif
 
   a&=0xffffff;
-#if 0
-    PicoWriteS68k8_(a, d);
-/*  if ((a&0xfc0000)!=0x080000) {
-    PicoWriteS68k8_(a, d);
-    return;
-  }
-  printf("r3: %02x\n", Pico_mcd->s68k_regs[3]);
-  PicoWriteS68k8__(a,d);*/
-  return;
-#endif
 
   // prg RAM
   if (a < 0x80000) {
     u8 *pm=(u8 *)(Pico_mcd->prg_ram+(a^1));
-    *pm=d;
+    if (a >= (Pico_mcd->s68k_regs[2]<<8)) *pm=d;
     return;
   }
 
@@ -1149,7 +1213,9 @@ static void PicoWriteS68k16(u32 a,u16 d)
 
   // prg RAM
   if (a < 0x80000) {
-    *(u16 *)(Pico_mcd->prg_ram+a)=d;
+    wrdprintf("s68k_prgram w16: [%06x] %04x @%06x", a, d, SekPcS68k);
+    if (a >= (Pico_mcd->s68k_regs[2]<<8)) // needed for Dungeon Explorer
+      *(u16 *)(Pico_mcd->prg_ram+a)=d;
     return;
   }
 
@@ -1233,8 +1299,10 @@ static void PicoWriteS68k32(u32 a,u32 d)
 
   // prg RAM
   if (a < 0x80000) {
-    u16 *pm=(u16 *)(Pico_mcd->prg_ram+a);
-    pm[0]=(u16)(d>>16); pm[1]=(u16)d;
+    if (a >= (Pico_mcd->s68k_regs[2]<<8)) {
+      u16 *pm=(u16 *)(Pico_mcd->prg_ram+a);
+      pm[0]=(u16)(d>>16); pm[1]=(u16)d;
+    }
     return;
   }
 
@@ -1246,6 +1314,7 @@ static void PicoWriteS68k32(u32 a,u32 d)
       gfx_cd_write16(a,   d>>16);
       gfx_cd_write16(a+2, d&0xffff);
     } else {
+      if ((a&0x1fe) == 0xe) dprintf("s68k FIXME: w32 [%02x]", a&0x3f);
       s68k_reg_write8(a,   d>>24);
       s68k_reg_write8(a+1,(d>>16)&0xff);
       s68k_reg_write8(a+2,(d>>8) &0xff);
@@ -1387,7 +1456,7 @@ static u32 PicoCheckPcS68k(u32 pc)
 #endif
 
 
-void PicoMemSetupCD()
+PICO_INTERNAL void PicoMemSetupCD(void)
 {
   dprintf("PicoMemSetupCD()");
 #ifdef EMU_C68K
@@ -1408,6 +1477,8 @@ void PicoMemSetupCD()
   PicoCpuS68k.write16=PicoWriteS68k16;
   PicoCpuS68k.write32=PicoWriteS68k32;
 #endif
+  // m68k_poll_addr = m68k_poll_cnt = 0;
+  s68k_poll_adclk = s68k_poll_cnt = 0;
 }