diff --git a/main.cpp b/main.cpp
index 7386918..5eeb685 100644
--- a/main.cpp
+++ b/main.cpp
@@ -3,6 +3,8 @@
 
 int main(int argc, char** argv) {
 
-
+	int i = 10;
+	int x = i++ + (i++ + 1);
+	// aci, i == 12 ; x == 21
 	return 0;
 }
\ No newline at end of file
diff --git a/vbvm.vcxproj b/vbvm.vcxproj
index 392a2e4..130f113 100644
--- a/vbvm.vcxproj
+++ b/vbvm.vcxproj
@@ -76,6 +76,13 @@
     </Link>
   </ItemDefinitionGroup>
   <ItemGroup>
+    <ClCompile Include="main.cpp" />
+    <ClCompile Include="stack.cpp" />
+    <ClCompile Include="vm.cpp" />
+  </ItemGroup>
+  <ItemGroup>
+    <ClInclude Include="stack.h" />
+    <ClInclude Include="vm.h" />
   </ItemGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">
diff --git a/vbvm.vcxproj.filters b/vbvm.vcxproj.filters
index f81daba..e238e83 100644
--- a/vbvm.vcxproj.filters
+++ b/vbvm.vcxproj.filters
@@ -14,4 +14,23 @@
       <Extensions>rc;ico;cur;bmp;dlg;rc2;rct;bin;rgs;gif;jpg;jpeg;jpe;resx;tiff;tif;png;wav;mfcribbon-ms</Extensions>
     </Filter>
   </ItemGroup>
+  <ItemGroup>
+    <ClCompile Include="main.cpp">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+    <ClCompile Include="stack.cpp">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+    <ClCompile Include="vm.cpp">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+  </ItemGroup>
+  <ItemGroup>
+    <ClInclude Include="vm.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
+    <ClInclude Include="stack.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
+  </ItemGroup>
 </Project>
\ No newline at end of file
diff --git a/vm.cpp b/vm.cpp
index 5bb5d7e..34cf394 100644
--- a/vm.cpp
+++ b/vm.cpp
@@ -1,5 +1,9 @@
 #include "vm.h"
 
+#define MAX_EXTERNAL_CALLS	256
+#define MAX_DATA_STACK		256
+#define MAX_CALL_STACK		256
+
 enum OPS {
 	OP_NOP = 0,
 	OP_PUSH,
@@ -34,19 +38,52 @@ enum OPS {
 };
 
 typedef void(*t_extcall)(t_stack&);
-t_extcall external_calls[100];
+t_extcall external_calls[MAX_EXTERNAL_CALLS];
 int numcallbacks = 0;
 	
 const unsigned char* vm_program = nullptr;
 int vm_pc = 0;
+int vm_cycles = 0;
+t_stack vm_datastack;
+t_stack vm_callstack;
 
 void vm_init(const unsigned char* program) {
 	vm_program = program;
 	vm_pc = 0;
+	vm_datastack = stack_new(MAX_DATA_STACK);
+	vm_callstack = stack_new(MAX_CALL_STACK);
 }
 
-void vm_step() {
 
+void vm_step() {
+	switch (vm_program[vm_pc++]) {
+	case OP_NOP: vm_cycles++; break;
+	case OP_PUSH: stack_push(vm_datastack, vm_program[vm_pc++]); vm_cycles++; break;
+	case OP_POP: stack_pop(vm_datastack); vm_cycles++; break;
+	case OP_DUP: stack_push(vm_datastack, stack_peek(vm_datastack)); vm_cycles++; break;
+	case OP_LOAD: vm_cycles++; break;
+	case OP_STORE: vm_cycles++; break;
+	case OP_JMP: vm_pc = vm_program[vm_pc] + (vm_program[vm_pc + 1] << 8);  vm_cycles++; break;
+	case OP_JNT: vm_cycles++; break;
+	case OP_JTR: vm_cycles++; break;
+	case OP_JSR: vm_cycles++; break;
+	case OP_RET: vm_cycles++; break;
+	case OP_CALL: external_calls[vm_program[vm_pc++]](vm_datastack); vm_cycles++; break;
+	case OP_ADD: vm_cycles++; break;
+	case OP_SUB: vm_cycles++; break;
+	case OP_MUL: vm_cycles++; break;
+	case OP_DIV: vm_cycles++; break;
+	case OP_MOD: vm_cycles++; break;
+	case OP_AND: vm_cycles++; break;
+	case OP_OR: vm_cycles++; break;
+	case OP_NOT: vm_cycles++; break;
+	case OP_NEG: vm_cycles++; break;
+	case OP_INC: vm_cycles++; break;
+	case OP_EQ: vm_cycles++; break;
+	case OP_NEQ: vm_cycles++; break;
+	case OP_LT: vm_cycles++; break;
+	case OP_GT: vm_cycles++; break;
+	}
 }
 
 void vm_register_call(void(*callback)(t_stack&)) {