diff --git a/bin/loader.cpp b/bin/loader.cpp
index 063710e..4c2a8ef 100644
--- a/bin/loader.cpp
+++ b/bin/loader.cpp
@@ -390,10 +390,6 @@ void GlobalInit()
 	// 0x0a06 - MinusOne
 	memoryWriteLong(0xffffffff, MacOS::MinusOne);
 
-
-	// todo -- expects high stack, low heap.
-	// the allocator currently works from the top down,
-	// so put stack at top of memory?
 	
 	// 0x0130 -- ApplLimit
 	memoryWriteLong(Flags.memorySize - Flags.stackSize - 1, MacOS::ApplLimit);
@@ -405,7 +401,7 @@ void CreateStack()
 	// allocate stack, set A7...
 
 	uint32_t address;
-	uint16_t error;
+	//uint16_t error;
 
 #if 0
 	Flags.stackSize = (Flags.stackSize + 3) & ~0x03;
@@ -892,10 +888,8 @@ int main(int argc, char **argv)
 	// for pre-fetch.
 	memorySetMemory(Memory, MemorySize);
 
-	// should we subtract memory from the top
-	// for the stack vs allocating it?
 
-	MM::Init(Memory, MemorySize - Flags.stackSize, kGlobalSize);
+	MM::Init(Memory, MemorySize, kGlobalSize, Flags.stackSize);
 	OS::Init();
 	MPW::Init(argc, argv, defines);
 
diff --git a/toolbox/mm.cpp b/toolbox/mm.cpp
index fced9d2..ad94556 100644
--- a/toolbox/mm.cpp
+++ b/toolbox/mm.cpp
@@ -50,6 +50,7 @@ namespace
 
 	uint8_t *Memory;
 	uint32_t MemorySize;
+	uint32_t HeapSize;
 
 	// queue of free Handles
 	std::deque<uint32_t> HandleQueue;
@@ -104,16 +105,17 @@ namespace
 namespace MM
 {
 
-	bool Init(uint8_t *memory, uint32_t memorySize, uint32_t reserved)
+	bool Init(uint8_t *memory, uint32_t memorySize, uint32_t globals, uint32_t stack)
 	{
 		int ok;
 
 		Memory = memory;
 		MemorySize = memorySize;
+		HeapSize = memorySize - stack;
 
 		ok = mplite_init(&pool, 
-			memory + reserved, 
-			memorySize - reserved, 
+			memory + globals, 
+			memorySize - globals - stack, 
 			32, 
 			NULL);
 
@@ -123,6 +125,9 @@ namespace MM
 
 		if (!alloc_handle_block()) return false;
 
+
+		// create system handles for the stack and global space?
+
 		return true;
 	}
 
@@ -761,7 +766,7 @@ namespace MM
 
 		// MemorySize is the top of the heap. stack is after it.
 
-		return sp - MemorySize;
+		return sp - HeapSize;
 	}
 
 
@@ -1446,7 +1451,9 @@ namespace MM
 
 		Log("%04x StripAddress(%08x)\n", trap, address);
 
-		address &= 0x00ffffff;
+		if (MemorySize <= 0x00ffffff)
+			address &= 0x00ffffff;
+
 		return address;
 	}
 
diff --git a/toolbox/mm.h b/toolbox/mm.h
index d50b721..6e2ad99 100644
--- a/toolbox/mm.h
+++ b/toolbox/mm.h
@@ -32,7 +32,7 @@ namespace MM
 		uint16_t HUnlock(uint32_t handle);
 	}
 
-	bool Init(uint8_t *memory, uint32_t memorySize, uint32_t reserved);
+	bool Init(uint8_t *memory, uint32_t memorySize, uint32_t globals, uint32_t stack);
 
 
 	uint16_t BlockMove(uint16_t trap);
@@ -69,7 +69,7 @@ namespace MM
 
 	uint16_t HPurge(uint16_t trap);
 	uint16_t HNoPurge(uint16_t trap);
-	
+
 	uint16_t HSetRBit(uint16_t trap);
 	uint16_t HClrRBit(uint16_t trap);