diff --git a/README.md b/README.md
index 88d3e71..eefd222 100644
--- a/README.md
+++ b/README.md
@@ -15,6 +15,7 @@ classDiagram
         + abstract void write(Address address, Word data)
         + abstract void dump()
     }
+    class Program
     class ProgramCounter {
         - int PC
         - int SysTick
@@ -28,7 +29,6 @@ classDiagram
         + boolean halted()
         + void halt()
     }
-    class Program
     class Instruction {
         + abstract void execute(Memory memory, ProgramCounter pc)
         # abstract String opcode()
@@ -62,14 +62,67 @@ classDiagram
         + String toString()
         + boolean equals(Object other)
     }
-    class LongMemory {
-        - long[] memory
-        + LongMemory()
-        + LongMemory(int size)
-        + Word read(Address address)
-        + int size()
-        + void write(Address address, Word data)
-        + void dump()
+    class Add {
+        - Address src
+        - Word imm
+        - Address dest
+        + Add(Address src, Word imm, Address dest)
+        + void execute(Memory memory, ProgramCounter PC)
+        + String opcode()
+        + Object[] operands()
+        + String toString()
+    }
+    class Copy {
+        - Word imm
+        - Address dest
+        + Copy(Word imm, Address dest)
+        + void execute(Memory memory, ProgramCounter PC)
+        + String opcode()
+        + Object[] operands()
+        + String toString()
+    }
+    class Halt {
+        + Halt()
+        + void execute(Memory memory, ProgramCounter PC)
+        + String opcode()
+        + Object[] operands()
+        + String toString()
+    }
+    class Jump {
+        - int index
+        + Jump(int index)
+        + void execute(Memory memory, ProgramCounter PC)
+        + String opcode()
+        + Object[] operands()
+        + String toString()
+    }
+    class JumpEq {
+        - int index
+        - Address src
+        - Word imm
+        + JumpEq(int index, Address src, Word imm)
+        + void execute(Memory memory, ProgramCounter PC)
+        + String opcode()
+        + Object[] operands()
+        + String toString()
+    }
+    class Mul {
+        - Address src1
+        - Address src2
+        - Address dest
+        + Mul(Address src1, Address src2, Address dest)
+        + void execute(Memory memory, ProgramCounter PC)
+        + String opcode()
+        + Object[] operands()
+        + String toString()
+    }
+    class Print {
+        - Address address
+        + Print(Address address)
+        + void execute(Memory memory, ProgramCounter PC)
+        + String opcode()
+        + Object[] operands()
+        + String toString()
     }
     Memory <|-- LongMemory
     Word <|-- LongWord
@@ -79,4 +132,38 @@ classDiagram
     Computer --> Memory
     Computer --> Program
     Computer --> ProgramCounter
+    ProgramCounter --> Program
+    ProgramCounter --> Instruction
+    ProgramCounter : +toString()
+    Instruction : +toString()
+    Instruction <|-- Add
+    Instruction <|-- Copy
+    Instruction <|-- Halt
+    Instruction <|-- Jump
+    Instruction <|-- JumpEq
+    Instruction <|-- Mul
+    Instruction <|-- Print
+    Add --> Address
+```
+
+```mermaid
+sequenceDiagram
+participant Computer
+participant Program
+participant Memory
+participant ProgramCounter
+participant Instruction
+
+Computer -> Program: load(program)
+loop Program Execution
+    Program -> Computer: run()
+    loop Instructions Execution
+        Computer -> ProgramCounter: incPC()
+        ProgramCounter -> Program: getPC()
+        Program -> Program: executeInstruction()
+        Program -> Instruction: execute(memory, PC)
+        Instruction -> Memory: read/write(address)
+        Program -> ProgramCounter: incPC()
+    end
+end
 ```