diff --git a/src/emu.cpp b/src/emu.cpp
index 494873c..a5cdcb2 100644
--- a/src/emu.cpp
+++ b/src/emu.cpp
@@ -1,8 +1,10 @@
-#include "emu.h"
+#include <cstdint> // uint8_t, uint32_t
+
 #include "cpu.h"
+#include "emu.h"
 #include "ruc/format/print.h"
 
-void Emu::init(unsigned int frequency)
+void Emu::init(uint32_t frequency)
 {
 	m_frequency = frequency;
 }
@@ -28,13 +30,13 @@ void Emu::addMemorySpace(const char* name, int size)
 	m_memory_spaces.emplace(name, memory);
 }
 
-void Emu::writeMemory(const char* memory_space, unsigned int location, uint8_t value)
+void Emu::writeMemory(const char* memory_space, uint32_t location, uint8_t value)
 {
 	print("{} {} {}\n", memory_space, location, value);
 	m_memory_spaces[memory_space][location] = value;
 }
 
-uint8_t Emu::readMemory(const char* memory_space, unsigned int location)
+uint8_t Emu::readMemory(const char* memory_space, uint32_t location)
 {
-	// return m_memory_spaces[memory_space][location];
+	return m_memory_spaces[memory_space][location];
 }
diff --git a/src/emu.h b/src/emu.h
index 1d8dc60..8a48da0 100644
--- a/src/emu.h
+++ b/src/emu.h
@@ -1,6 +1,6 @@
 #pragma once
 
-#include <cstdint>
+#include <cstdint> // uint8_t, uint32_t
 #include <unordered_map>
 #include <vector>
 
@@ -11,20 +11,20 @@ class Emu final : public ruc::Singleton<Emu> {
 public:
 	Emu(s) {}
 
-	void init(unsigned int frequency);
+	void init(uint32_t frequency);
 
 	void update();
 
 	void addProcessingUnit(ProcessingUnit* processing_unit);
 	void addMemorySpace(const char* name, int size);
 
-	void writeMemory(const char* memory_space, unsigned int location, uint8_t value);
+	void writeMemory(const char* memory_space, uint32_t location, uint8_t value);
 
-	uint8_t readMemory(const char* memory_space, unsigned int location);
+	uint8_t readMemory(const char* memory_space, uint32_t location);
 
 private:
-	unsigned int m_frequency;
-	unsigned int m_cycle = 0;
+	uint32_t m_frequency;
+	uint32_t m_cycle = 0;
 
 	std::vector<ProcessingUnit*> m_processing_units;
 	std::unordered_map<const char*, std::vector<uint8_t>> m_memory_spaces;
diff --git a/src/processing-unit.cpp b/src/processing-unit.cpp
index 322d368..935e6c4 100644
--- a/src/processing-unit.cpp
+++ b/src/processing-unit.cpp
@@ -5,11 +5,11 @@
  * SPDX-License-Identifier: MIT
  */
 
-#include <iostream>
+#include <cstdint> // uint32_t
 
 #include "processing-unit.h"
 
-ProcessingUnit::ProcessingUnit(unsigned int frequency)
+ProcessingUnit::ProcessingUnit(uint32_t frequency)
 	: m_frequency(frequency)
 {
 }
@@ -18,7 +18,7 @@ ProcessingUnit::~ProcessingUnit()
 {
 }
 
-unsigned int ProcessingUnit::frequency()
+uint32_t ProcessingUnit::frequency()
 {
 	return m_frequency;
 }
diff --git a/src/processing-unit.h b/src/processing-unit.h
index 2d1ecea..09509e8 100644
--- a/src/processing-unit.h
+++ b/src/processing-unit.h
@@ -7,15 +7,17 @@
 
 #pragma once
 
+#include <cstdint> // uint32_t
+
 class ProcessingUnit {
 public:
-	ProcessingUnit(unsigned int frequency);
+	ProcessingUnit(uint32_t frequency);
 	virtual ~ProcessingUnit();
 
 	virtual void update() = 0;
 
-	unsigned int frequency();
+	uint32_t frequency();
 
 private:
-	unsigned int m_frequency { 0 };
+	uint32_t m_frequency { 0 };
 };