diff --git a/emulator.cpp b/emulator.cpp
index 3072b21..7db1c51 100644
--- a/emulator.cpp
+++ b/emulator.cpp
@@ -4,7 +4,7 @@
 void Emulator::init(size_t memorysize, FILE *bin){
   memory.init(memorysize);
   memory.load_binary(bin);
-  instructions.init(0, (int)memorysize/2, memory);
+  instructions.init(0, (int)memorysize, memory);
 }
 
 void Emulator::free(){
@@ -20,6 +20,10 @@ void Emulator::dump_registers(){
   printf("ecx = 0x%08x (%d)\n", instructions.registers[1], instructions.registers[1]);
   printf("edx = 0x%08x (%d)\n", instructions.registers[2], instructions.registers[2]);
   printf("ebx = 0x%08x (%d)\n", instructions.registers[3], instructions.registers[3]);
+  printf("esp = 0x%08x (%d)\n", instructions.registers[4], instructions.registers[4]);
+  printf("ebp = 0x%08x (%d)\n", instructions.registers[5], instructions.registers[5]);
+  printf("esi = 0x%08x (%d)\n", instructions.registers[6], instructions.registers[6]);
+  printf("edi = 0x%08x (%d)\n", instructions.registers[7], instructions.registers[7]);
   printf("eip = 0x%08x (%d)\n", instructions.eip, instructions.eip);
 }
 
diff --git a/include/instructions.h b/include/instructions.h
index c5626f2..0aee08a 100644
--- a/include/instructions.h
+++ b/include/instructions.h
@@ -45,6 +45,14 @@ public:
   void dec_ebp();       // 0x4d
   void dec_esi();       // 0x4e
   void dec_edi();       // 0x4f
+  void push_eax();      // 0x50
+  void push_ecx();      // 0x51
+  void push_edx();      // 0x52
+  void push_ebx();      // 0x53
+  void push_esp();      // 0x54
+  void push_ebp();      // 0x55
+  void push_esi();      // 0x56
+  void push_edi();      // 0x57
   void jne_imm8();      // 0x75
   void opcode_83();     // 0x83
   void mov_rm32_r32();  // 0x89
diff --git a/instructions.cpp b/instructions.cpp
index 84574fd..0954ba0 100644
--- a/instructions.cpp
+++ b/instructions.cpp
@@ -38,6 +38,14 @@ void Instructions::init_instructions(){
   this->instructions[0x4d] = &Instructions::dec_ebp;
   this->instructions[0x4e] = &Instructions::dec_esi;
   this->instructions[0x4f] = &Instructions::dec_edi;
+  this->instructions[0x50] = &Instructions::push_eax;
+  this->instructions[0x51] = &Instructions::push_ecx;
+  this->instructions[0x52] = &Instructions::push_edx;
+  this->instructions[0x53] = &Instructions::push_ebx;
+  this->instructions[0x54] = &Instructions::push_esp;
+  this->instructions[0x55] = &Instructions::push_ebp;
+  this->instructions[0x56] = &Instructions::push_esi;
+  this->instructions[0x57] = &Instructions::push_edi;
   this->instructions[0x75] = &Instructions::jne_imm8;
   this->instructions[0x83] = &Instructions::opcode_83;
   this->instructions[0x89] = &Instructions::mov_rm32_r32;
@@ -248,6 +256,54 @@ void Instructions::dec_esi(){
   this->registers[6]--;
 }
 
+void Instructions::push_eax(){
+  //printf("push_eax called.\n");
+  this->registers[4] -= 4;
+  memory.write_uint32(this->registers[4], this->registers[0]);
+}
+
+void Instructions::push_ecx(){
+  //printf("push_ecx called.\n");
+  this->registers[4] -= 4;
+  memory.write_uint32(this->registers[4], this->registers[1]);
+}
+
+void Instructions::push_edx(){
+  //printf("push_edx called.\n");
+  this->registers[4] -= 4;
+  memory.write_uint32(this->registers[4], this->registers[2]);
+}
+
+void Instructions::push_ebx(){
+  //printf("push_ebx called.\n");
+  this->registers[4] -= 4;
+  memory.write_uint32(this->registers[4], this->registers[3]);
+}
+
+void Instructions::push_esp(){
+  //printf("push_esp called.\n");
+  this->registers[4] -= 4;
+  memory.write_uint32(this->registers[4], this->registers[4]);
+}
+
+void Instructions::push_ebp(){
+  //printf("push_ebp called.\n");
+  this->registers[4] -= 4;
+  memory.write_uint32(this->registers[4], this->registers[5]);
+}
+
+void Instructions::push_esi(){
+  //printf("push_esi called.\n");
+  this->registers[4] -= 4;
+  memory.write_uint32(this->registers[4], this->registers[6]);
+}
+
+void Instructions::push_edi(){
+  //printf("push_edi called.\n");
+  this->registers[4] -= 4;
+  memory.write_uint32(this->registers[4], this->registers[7]);
+}
+
 void Instructions::dec_edi(){
   //printf("dec_edi called.\n");
   this->registers[7]--;