higan_v093r11_link2.patch

diff -x higan -x '*.so' -x '*~' -x '*.o' -uNr higan_v093r11_sockpair/src/gb/cpu/mmio.cpp higan_v093r11_link2/src/gb/cpu/mmio.cpp
--- higan_v093r11_sockpair/src/gb/cpu/mmio.cpp	2013-12-24 06:22:02.000000000 +0000
+++ higan_v093r11_link2/src/gb/cpu/mmio.cpp	2013-12-25 05:20:27.823709075 +0000
@@ -53,12 +53,12 @@
     
     if(interface->tracer.open()) {
       char buffer[1024];
-      sprintf(buffer, "SB R 0x%.2x\n", 0xff);
+      sprintf(buffer, "SB R 0x%.2x\n", status.serial_data);
       interface->tracer.print(buffer);
       interface->tracer.flush();
     }
     
-    return 0xff;
+    return status.serial_data;
   }
 
   if(addr == 0xff02) {  //SC
@@ -197,7 +197,17 @@
     
     status.serial_transfer = data & 0x80;
     status.serial_clock = data & 0x01;
-    if(status.serial_transfer) status.serial_bits = 8;
+    if(status.serial_transfer) status.serial_bits = 16;
+    
+    if(status.serial_transfer && status.serial_clock) {
+      // internal clock
+      char bit[2];
+      bit[0] = '0';
+      bit[1] = '\0';
+      
+      write(sockSCK, bit, 1);
+    }
+    
     return;
   }
 
diff -x higan -x '*.so' -x '*~' -x '*.o' -uNr higan_v093r11_sockpair/src/gb/cpu/timing.cpp higan_v093r11_link2/src/gb/cpu/timing.cpp
--- higan_v093r11_sockpair/src/gb/cpu/timing.cpp	2013-12-24 08:34:43.862134958 +0000
+++ higan_v093r11_link2/src/gb/cpu/timing.cpp	2013-12-25 05:27:43.555726032 +0000
@@ -65,17 +65,125 @@
   }
 
   status.div++;
-}
 
-void CPU::timer_8192hz() {
-  if(status.serial_transfer && status.serial_clock) {
-    if(--status.serial_bits == 0) {
-      status.serial_transfer = 0;
-      interrupt_raise(Interrupt::Serial);
+  //
+  
+  int half_time = !((status.clock &  511) == 0);
+  
+  if(!half_time && !(status.serial_bits%2)) {
+    if(status.serial_transfer && status.serial_clock) {
+      // using internal clock
+      // shift clock is low
+      
+      // shift highest bit out
+      int highest_bit = 0x80 & status.serial_data;
+      { char bit[2];
+	bit[0] = highest_bit?'1':'0';
+	bit[1] = '\0';
+	
+	write(sockSIO, bit, 1);
+      }
+      status.serial_data = status.serial_data << 1;
+      
+      // signal that the shift clock went high
+      { char bit[2];
+	bit[0] = '1';
+	bit[1] = '\0';
+	
+	write(sockSCK, bit, 1);
+      }
+      
+      --status.serial_bits;
+    }
+    else if(status.serial_transfer && !status.serial_clock) {
+      // wait for the shift clock to go low
+      char buf[2];
+      buf[0] = '?';
+      buf[1] = 0;
+      if(1 == recv(sockSCK, buf, 1, MSG_DONTWAIT)) {
+	if(buf[0]=='1')
+	  printf("ext SCK went high expected low\n");
+      }
+      
+      if(buf[0] == '0') {
+	// shift highest bit out
+	int highest_bit = 0x80 & status.serial_data;
+	{ char bit[2];
+	  bit[0] = highest_bit?'1':'0';
+	  bit[1] = '\0';
+	  
+	  write(sockSIO, bit, 1);
+	}
+	status.serial_data = status.serial_data << 1;
+	
+	--status.serial_bits;
+      }
+    }
+  }
+  else if(half_time && (status.serial_bits%2)) {
+    if(status.serial_transfer && status.serial_clock) {
+      // shift clock is high
+      // read a bit in
+      // TODO: If we dont get it what? should we wait next turn or
+      //       just say we read a zero
+      //       should we take a note that we need to drain the socket of
+      //       a bit?
+      char bit[2];
+      bit[0] = '?';
+      bit[1] = 0;
+      if(1 == recv(sockSIO, bit, 1, MSG_WAITALL)) { // this shouldn't(?) block but it helps to do so
+	if(bit[0] == '1') status.serial_data |= 1;
+	
+	if(--status.serial_bits == 0) {
+	  status.serial_transfer = 0;
+	  interrupt_raise(Interrupt::Serial);
+	}
+	else {
+	  // signal that the shift clock went low
+	  { char bit[2];
+	    bit[0] = '0';
+	    bit[1] = '\0';
+	    
+	    write(sockSCK, bit, 1);
+	  }
+	}
+      }
+      else {
+	printf("disaster 001 occured\n");
+      }
+    }
+    else if(status.serial_transfer && !status.serial_clock) {
+      // wait for the external clock to go high
+      { char buf[2];
+	buf[0] = '?';
+	buf[1] = 0;
+	if(1 == recv(sockSCK, buf, 1, MSG_WAITALL)) {
+	  if(buf[0]=='0')
+	    printf("ext SCK low expected high\n");
+	}
+      }
+      
+      // read a bit in
+      char bit[2];
+      bit[0] = '?';
+      bit[1] = 0;
+      if(1 == recv(sockSIO, bit, 1, MSG_DONTWAIT)) { // could block but not needed
+	if(bit[0] == '1') status.serial_data |= 1;
+	
+	if(--status.serial_bits == 0) {
+	  status.serial_transfer = 0;
+	  interrupt_raise(Interrupt::Serial);
+	}
+      }
+      else {
+	printf("disaster 002 occured\n");
+      }
     }
   }
 }
 
+void CPU::timer_8192hz() {}
+
 void CPU::timer_4096hz() {
   if(status.timer_enable && status.timer_clock == 0) {
     if(++status.tima == 0) {