From 9a8ffeeeea54301c5289fd510aece552175ce13d Mon Sep 17 00:00:00 2001
From: notaz <notasas@gmail.com>
Date: Sat, 6 Oct 2007 16:06:15 +0000
Subject: [PATCH] fast mode timing changed (again...)

git-svn-id: file:///home/notaz/opt/svn/PicoDrive@271 be3aeb3a-fb24-0410-a615-afba39da0efa
---
 Pico/MemoryCmn.c      |  6 +++---
 Pico/Pico.c           | 36 ++++++++++++++++++++++++------------
 Pico/PicoFrameHints.c |  2 +-
 Pico/sound/sound.c    |  4 +---
 4 files changed, 29 insertions(+), 19 deletions(-)

diff --git a/Pico/MemoryCmn.c b/Pico/MemoryCmn.c
index 8e4d04e..219a094 100644
--- a/Pico/MemoryCmn.c
+++ b/Pico/MemoryCmn.c
@@ -72,17 +72,17 @@ static
 void z80WriteBusReq(u32 d)
 {
   d&=1; d^=1;
-  if (Pico.m.scanline != -1)
+  //if (Pico.m.scanline != -1)
   {
     if(!d) {
       // this is for a nasty situation where Z80 was enabled and disabled in the same 68k timeslice (Golden Axe III)
       if (Pico.m.z80Run) {
         int lineCycles;
         z80stopCycle = SekCyclesDone();
-        if (Pico.m.z80Run&2)
+        if ((Pico.m.z80Run&2) && Pico.m.scanline != -1)
              lineCycles=(488-SekCyclesLeft)&0x1ff;
         else lineCycles=z80stopCycle-z80startCycle; // z80 was started at current line
-        if (lineCycles > 0 && lineCycles <= 488) {
+        if (lineCycles > 0) { // && lineCycles <= 488) {
           //dprintf("zrun: %i/%i cycles", lineCycles, (lineCycles>>1)-(lineCycles>>5));
           lineCycles=(lineCycles>>1)-(lineCycles>>5);
           z80_run(lineCycles);
diff --git a/Pico/Pico.c b/Pico/Pico.c
index 96a6da0..c6bf03e 100644
--- a/Pico/Pico.c
+++ b/Pico/Pico.c
@@ -423,24 +423,34 @@ static int PicoFrameHints(void)
 #include "PicoFrameHints.c"
 #endif
 
-// helper z80 runner
+// helper z80 runner. Runs only if z80 is enabled at this point
+// (z80WriteBusReq will handle the rest)
 static void PicoRunZ80Simple(int line_from, int line_to)
 {
-  int line_from_r=line_from, line_to_r=line_to, line = line_from;
+  int line_from_r=line_from, line_to_r=line_to, line=0;
   int line_sample = Pico.m.pal ? 68 : 93;
 
-  if(!(PicoOpt&4) || Pico.m.z80Run == 0) { line_from_r = line_to_r; line_to_r = 0; }
+  if (!(PicoOpt&4) || Pico.m.z80Run == 0) line_to_r = 0;
+  else {
+    extern const unsigned short vcounts[];
+    if (z80startCycle) {
+      line = vcounts[z80startCycle>>8];
+      if (line > line_from)
+        line_from_r = line;
+    }
+    z80startCycle = SekCyclesDone();
+  }
 
-  if(PicoOpt&1) {
+  if (PicoOpt&1) {
     // we have ym2612 enabled, so we have to run Z80 in lines, so we could update DAC and timers
-    for(; line < line_to; line++) {
+    for (line = line_from; line < line_to; line++) {
       sound_timers_and_dac(line);
-      if((line == 224 || line == line_sample) && PsndOut) getSamples(line);
-      if(line == 32 && PsndOut) emustatus &= ~1;
-      if(line >= line_from_r && line < line_to_r)
+      if ((line == 224 || line == line_sample) && PsndOut) getSamples(line);
+      if (line == 32 && PsndOut) emustatus &= ~1;
+      if (line >= line_from_r && line < line_to_r)
         z80_run(228);
     }
-  } else if(line_to_r-line_from_r > 0) {
+  } else if (line_to_r-line_from_r > 0) {
     z80_run(228*(line_to_r-line_from_r));
     // samples will be taken by caller
   }
@@ -482,6 +492,7 @@ static int PicoFrameSimple(void)
   Pico.video.status|=0x200;
 
   Pico.m.scanline=-1;
+  z80startCycle=0;
 
   SekCyclesReset();
 
@@ -507,11 +518,12 @@ static int PicoFrameSimple(void)
   if(sects) {
     int c = sects*cycles_68k_block;
 
-    lines += sects*lines_step;
-    PicoRunZ80Simple(line, lines);
-    // this is for approriate line counter, etc
+    // this "run" is for approriate line counter, etc
     SekCycleCnt += c;
     SekCycleAim += c;
+
+    lines += sects*lines_step;
+    PicoRunZ80Simple(line, lines);
   }
 
   // here we render sound if ym2612 is disabled
diff --git a/Pico/PicoFrameHints.c b/Pico/PicoFrameHints.c
index 562229f..c14040a 100644
--- a/Pico/PicoFrameHints.c
+++ b/Pico/PicoFrameHints.c
@@ -22,7 +22,7 @@
     else { \
       cnt = SekCyclesDone() - z80startCycle; \
       cnt = (cnt>>1)-(cnt>>5); \
-      if (cnt > (z80_cycles)) cnt = z80_cycles; \
+      if (cnt < 0 || cnt > (z80_cycles)) cnt = z80_cycles; \
       Pico.m.z80Run |= 2; \
       z80CycleAim+=cnt; \
     } \
diff --git a/Pico/sound/sound.c b/Pico/sound/sound.c
index 32f2295..8bec0ba 100644
--- a/Pico/sound/sound.c
+++ b/Pico/sound/sound.c
@@ -106,9 +106,7 @@ PICO_INTERNAL void sound_reset(void)
   // also clear the internal registers+addr line
   ym2612_regs = YM2612GetRegs();
   memset(ym2612_regs, 0, 0x200+4);
-  // setting these to 0 might confuse timing code,
-  // so better set to something like this instead
-  z80startCycle = z80stopCycle = 0x01000000;
+  z80startCycle = z80stopCycle = 0;
 
   sound_rerate(0);
 }
-- 
2.39.2