diff --git a/SheepShaver/src/BeOS/main_beos.cpp b/SheepShaver/src/BeOS/main_beos.cpp
index 99352882..d15039bd 100644
--- a/SheepShaver/src/BeOS/main_beos.cpp
+++ b/SheepShaver/src/BeOS/main_beos.cpp
@@ -229,7 +229,8 @@ static void *extra_stack = NULL;	// Stack for SIGSEGV inside interrupt handler
 uint32  SheepMem::page_size;		// Size of a native page
 uintptr SheepMem::zero_page = 0;	// Address of ro page filled in with zeros
 uintptr SheepMem::base;				// Address of SheepShaver data
-uintptr SheepMem::top;				// Top of SheepShaver data (stack like storage)
+uintptr SheepMem::proc;				// Bottom address of SheepShave procedures
+uintptr SheepMem::data;				// Top of SheepShaver data (stack like storage)
 static area_id SheepMemArea;		// SheepShaver data area ID
 
 
@@ -2109,7 +2110,7 @@ bool SheepMem::Init(void)
 		delete_area(old_sheep_area);
 
 	// Create area for SheepShaver data
-	base = 0x60000000;
+	proc = base = 0x60000000;
 	SheepMemArea = create_area(SHEEP_AREA_NAME, (void **)&base, B_BASE_ADDRESS, size, B_NO_LOCK, B_READ_AREA | B_WRITE_AREA);
 	if (SheepMemArea < 0)
 		return false;
@@ -2119,7 +2120,7 @@ bool SheepMem::Init(void)
 	zero_page = const_zero_page;
 
 	D(bug("SheepShaver area %ld at %p\n", SheepMemArea, base));
-	top = base + size;
+	data = base + size;
 	return true;
 }
 
diff --git a/SheepShaver/src/include/thunks.h b/SheepShaver/src/include/thunks.h
index 1c23b792..0dd2f62a 100644
--- a/SheepShaver/src/include/thunks.h
+++ b/SheepShaver/src/include/thunks.h
@@ -93,8 +93,9 @@ protected:
 	static uint32  page_size;
 	static uintptr zero_page;
 	static uintptr base;
-	static uintptr top;
-	static const uint32 size = 0x40000; // 256 KB
+	static uintptr data;
+	static uintptr proc;
+	static const uint32 size = 0x80000; // 512 KB
 public:
 	static bool Init(void);
 	static void Exit(void);
@@ -102,6 +103,7 @@ public:
 	static uint32 ZeroPage();
 	static uint32 Reserve(uint32 size);
 	static void Release(uint32 size);
+	static uint32 ReserveProc(uint32 size);
 	friend class SheepVar;
 };
 
@@ -123,14 +125,29 @@ inline uint32 SheepMem::ZeroPage()
 
 inline uint32 SheepMem::Reserve(uint32 size)
 {
-	top -= align(size);
-	assert(top >= base);
-	return top;
+	data -= align(size);
+	assert(data >= proc);
+	return data;
 }
 
 inline void SheepMem::Release(uint32 size)
 {
-	top += align(size);
+	data += align(size);
+}
+
+inline uint32 SheepMem::ReserveProc(uint32 size)
+{
+	uint32 mproc = proc;
+	proc += align(size);
+	assert(proc < data);
+	return mproc;
+}
+
+static inline uint32 SheepProc(const uint8 *proc, uint32 proc_size)
+{
+	uint32 mac_proc = SheepMem::ReserveProc(proc_size);
+	Host2Mac_memcpy(mac_proc, proc, proc_size);
+	return mac_proc;
 }
 
 class SheepVar