diff --git a/bsnes/emulator/emulator.hpp b/bsnes/emulator/emulator.hpp
index a6af8090..8f307e83 100644
--- a/bsnes/emulator/emulator.hpp
+++ b/bsnes/emulator/emulator.hpp
@@ -29,7 +29,7 @@ using namespace nall;
 
 namespace Emulator {
   static const string Name    = "bsnes";
-  static const string Version = "111.9";
+  static const string Version = "111.10";
   static const string Author  = "byuu";
   static const string License = "GPLv3";
   static const string Website = "https://byuu.org";
diff --git a/bsnes/sfc/ppu-fast/background.cpp b/bsnes/sfc/ppu-fast/background.cpp
index 547a503d..792e5be0 100644
--- a/bsnes/sfc/ppu-fast/background.cpp
+++ b/bsnes/sfc/ppu-fast/background.cpp
@@ -93,7 +93,7 @@ auto PPU::Line::renderBackground(PPU::IO::Background& self, uint8 source) -> voi
     tileNumber = (tileNumber & 0x03ff) + tiledataIndex & tileMask;
 
     uint16 address;
-    address = (tileNumber << colorShift) + (voffset & 7 ^ mirrorY);
+    address = (tileNumber << colorShift) + (voffset & 7 ^ mirrorY) & 0x7fff;
 
     uint64 data;
     data  = (uint64)ppu.vram[address +  0] <<  0;
diff --git a/bsnes/sfc/system/serialization.cpp b/bsnes/sfc/system/serialization.cpp
index 5900b273..75c0e5d9 100644
--- a/bsnes/sfc/system/serialization.cpp
+++ b/bsnes/sfc/system/serialization.cpp
@@ -1,10 +1,6 @@
 auto System::serialize(bool synchronize) -> serializer {
-  //deterministic serialization (synchronize=false) is only possible with select libco methods.
-  if(co_method() != "x86"
-  && co_method() != "amd64"
-  && co_method() != "arm"
-  && co_method() != "aarch64"
-  ) synchronize = true;
+  //deterministic serialization (synchronize=false) is only possible with select libco methods
+  if(!co_serializable()) synchronize = true;
 
   if(!information.serializeSize[synchronize]) return {};  //should never occur
   if(synchronize) runToSave();
diff --git a/libco/aarch64.c b/libco/aarch64.c
index 59162f20..b3ffcc49 100644
--- a/libco/aarch64.c
+++ b/libco/aarch64.c
@@ -59,10 +59,6 @@ static void co_init() {
   #endif
 }
 
-const char* co_method() {
-  return "aarch64";
-}
-
 cothread_t co_active() {
   if(!co_active_handle) co_active_handle = &co_active_buffer;
   return co_active_handle;
@@ -102,6 +98,10 @@ void co_switch(cothread_t handle) {
   co_swap(co_active_handle = handle, co_previous_handle);
 }
 
+int co_serializable() {
+  return 1;
+}
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/libco/amd64.c b/libco/amd64.c
index e9aef889..e9424c0b 100755
--- a/libco/amd64.c
+++ b/libco/amd64.c
@@ -115,10 +115,6 @@ static void crash() {
   assert(0);  /* called only if cothread_t entrypoint returns */
 }
 
-const char* co_method() {
-  return "amd64";
-}
-
 cothread_t co_active() {
   if(!co_active_handle) co_active_handle = &co_active_buffer;
   return co_active_handle;
@@ -158,6 +154,10 @@ void co_switch(cothread_t handle) {
   co_swap(co_active_handle = handle, co_previous_handle);
 }
 
+int co_serializable() {
+  return 1;
+}
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/libco/arm.c b/libco/arm.c
index 8d872bf5..95adf6b2 100644
--- a/libco/arm.c
+++ b/libco/arm.c
@@ -35,10 +35,6 @@ static void co_init() {
   #endif
 }
 
-const char* co_method() {
-  return "arm";
-}
-
 cothread_t co_active() {
   if(!co_active_handle) co_active_handle = &co_active_buffer;
   return co_active_handle;
@@ -77,6 +73,10 @@ void co_switch(cothread_t handle) {
   co_swap(co_active_handle = handle, co_previous_handle);
 }
 
+int co_serializable() {
+  return 1;
+}
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/libco/fiber.c b/libco/fiber.c
index f508b0f8..dd539c37 100755
--- a/libco/fiber.c
+++ b/libco/fiber.c
@@ -16,10 +16,6 @@ static void __stdcall co_thunk(void* coentry) {
   ((void (*)(void))coentry)();
 }
 
-const char* co_method() {
-  return "fiber";
-}
-
 cothread_t co_active() {
   if(!co_active_) {
     ConvertThreadToFiber(0);
@@ -50,6 +46,10 @@ void co_switch(cothread_t cothread) {
   SwitchToFiber(cothread);
 }
 
+int co_serializable() {
+  return 0;
+}
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/libco/libco.h b/libco/libco.h
index 0b94c2e9..88d00a72 100755
--- a/libco/libco.h
+++ b/libco/libco.h
@@ -13,12 +13,12 @@ extern "C" {
 
 typedef void* cothread_t;
 
-const char* co_method();
 cothread_t co_active();
 cothread_t co_derive(void*, unsigned int, void (*)(void));
 cothread_t co_create(unsigned int, void (*)(void));
 void co_delete(cothread_t);
 void co_switch(cothread_t);
+int co_serializable();
 
 #ifdef __cplusplus
 }
diff --git a/libco/ppc.c b/libco/ppc.c
index 314997c8..6b7f4acd 100755
--- a/libco/ppc.c
+++ b/libco/ppc.c
@@ -413,10 +413,6 @@ static void co_init_(void) {
   co_active_handle = co_create_(state_size, (uintptr_t)&co_switch);
 }
 
-const char* co_method() {
-  return "ppc";
-}
-
 cothread_t co_active() {
   if(!co_active_handle) co_init_();
 
@@ -429,3 +425,7 @@ void co_switch(cothread_t t) {
 
   CO_SWAP_ASM(t, old);
 }
+
+int co_serializable() {
+  return 0;
+}
diff --git a/libco/ppc64v2.c b/libco/ppc64v2.c
index fac464a6..3c296959 100644
--- a/libco/ppc64v2.c
+++ b/libco/ppc64v2.c
@@ -221,10 +221,6 @@ __asm__(
   ".size swap_context, .-swap_context\n"
 );
 
-const char* co_method() {
-  return "ppc64v2";
-}
-
 cothread_t co_active() {
   if(!co_active_handle) {
     co_active_handle = (struct ppc64_context*)malloc(MIN_STACK + sizeof(struct ppc64_context));
@@ -274,6 +270,10 @@ void co_switch(cothread_t to) {
   swap_context((struct ppc64_context*)to, from);
 }
 
+int co_serializable() {
+  return 1;
+}
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/libco/sjlj.c b/libco/sjlj.c
index b4faf17b..5af14729 100755
--- a/libco/sjlj.c
+++ b/libco/sjlj.c
@@ -33,10 +33,6 @@ static void springboard(int ignored) {
   }
 }
 
-const char* co_method() {
-  return "sjlj";
-}
-
 cothread_t co_active() {
   if(!co_running) co_running = &co_primary;
   return (cothread_t)co_running;
@@ -140,6 +136,10 @@ void co_switch(cothread_t cothread) {
   }
 }
 
+int co_serializable() {
+  return 0;
+}
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/libco/ucontext.c b/libco/ucontext.c
index 49fa976c..5ff76af3 100755
--- a/libco/ucontext.c
+++ b/libco/ucontext.c
@@ -26,10 +26,6 @@ extern "C" {
 static thread_local ucontext_t co_primary;
 static thread_local ucontext_t* co_running = 0;
 
-const char* co_module() {
-  return "ucontext";
-}
-
 cothread_t co_active() {
   if(!co_running) co_running = &co_primary;
   return (cothread_t)co_running;
@@ -81,6 +77,10 @@ void co_switch(cothread_t cothread) {
   swapcontext(old_thread, co_running);
 }
 
+int co_serializable() {
+  return 0;
+}
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/libco/x86.c b/libco/x86.c
index 8effa0d4..fa1c538f 100755
--- a/libco/x86.c
+++ b/libco/x86.c
@@ -69,10 +69,6 @@ static void crash() {
   assert(0);  /* called only if cothread_t entrypoint returns */
 }
 
-const char* co_method() {
-  return "x86";
-}
-
 cothread_t co_active() {
   if(!co_active_handle) co_active_handle = &co_active_buffer;
   return co_active_handle;
@@ -112,6 +108,10 @@ void co_switch(cothread_t handle) {
   co_swap(co_active_handle = handle, co_previous_handle);
 }
 
+int co_serializable() {
+  return 1;
+}
+
 #ifdef __cplusplus
 }
 #endif