diff --git a/asm/call.asm b/asm/call.asm
index 82266f607..3472dba3a 100644
--- a/asm/call.asm
+++ b/asm/call.asm
@@ -1,3 +1,4 @@
+
 ; Demonstrate calls
 ;
 ; Expected output:
diff --git a/asm/mult.asm b/asm/mult.asm
index ef8c65192..d9c1f890c 100644
--- a/asm/mult.asm
+++ b/asm/mult.asm
@@ -2,7 +2,7 @@
 #
 # Expected output: 72
 
-LDI R0,8
+LDI R0,8 
 LDI R1,9
 MUL R0,R1
 PRN R0
diff --git a/asm/test.asm b/asm/test.asm
new file mode 100644
index 000000000..1c63c2116
--- /dev/null
+++ b/asm/test.asm
@@ -0,0 +1,15 @@
+; Code to test the Sprint Challenge
+;
+; Expected output:
+; 1
+; 4
+; 5
+
+LDI R0,10
+LDI R1,20
+LDI R2,Test1
+CMP R0,R1
+JEQ R2       ; Does not jump because R0 != R1
+LDI R3,1
+PRN R3       ; Prints 1
+HLT
diff --git a/ls8/cpu.py b/ls8/cpu.py
index 9a307496e..402eb60ee 100644
--- a/ls8/cpu.py
+++ b/ls8/cpu.py
@@ -2,41 +2,61 @@
 
 import sys
 
-class CPU:
-    """Main CPU class."""
+HLT = 0b00000001
+LDI = 0b10000010
+PRN = 0b01000111
+MUL = 0b10100010
+PUSH = 0b01000101
+POP = 0b01000110
+CALL = 0b01010000
+RET = 0b00010001
+JMP = 0b01010100
+CMP = 0b10100111
+JEQ = 0b01010101
+JNE = 0b01010110
+SP = 7 
 
+class CPU:
     def __init__(self):
         """Construct a new CPU."""
-        pass
-
-    def load(self):
-        """Load a program into memory."""
-
-        address = 0
+        self.ram = [0] * 256
+        self.pc = 0
+        self.reg = [0] * 8
+        self.reg[7] = 0xF4 #refer PowerON state in Spec
+        self.running = True
+        self.fl = 0b00000000
 
-        # For now, we've just hardcoded a program:
+    def ram_read(self,addr):
+        return self.ram[addr]
 
-        program = [
-            # From print8.ls8
-            0b10000010, # LDI R0,8
-            0b00000000,
-            0b00001000,
-            0b01000111, # PRN R0
-            0b00000000,
-            0b00000001, # HLT
-        ]
+    def ram_write(self,val,addr):
+        self.ram[addr] = val
 
-        for instruction in program:
-            self.ram[address] = instruction
-            address += 1
+    def load(self,filename):
+        """Load a program into memory."""
 
+        address = 0
+       # program = []
+        try: 
+            with open(filename) as f:
+                for line in f:
+                    comment_split = line.split("#")
+                    maybe_binary_number = comment_split[0].strip()
+                    try:
+                        x = int(maybe_binary_number, 2)
+                        self.ram_write(x, address)
+                        address += 1
+                    except:
+                        continue
+        except FileNotFoundError:
+            print("Cannot find this file..")
 
     def alu(self, op, reg_a, reg_b):
         """ALU operations."""
-
-        if op == "ADD":
-            self.reg[reg_a] += self.reg[reg_b]
-        #elif op == "SUB": etc
+        # if op == "ADD":
+        #     self.reg[reg_a] += self.reg[reg_b]
+        if op == MUL: 
+            self.reg[reg_a] *= self.reg[reg_b]
         else:
             raise Exception("Unsupported ALU operation")
 
@@ -60,6 +80,74 @@ def trace(self):
 
         print()
 
+
+    def num_of_operands(self, instruction_to_execute):
+        return ((instruction_to_execute >> 6) & 0b11) + 1
+
     def run(self):
         """Run the CPU."""
-        pass
+        
+        #self.load()
+        while self.running:
+            instruction_to_excecute = self.ram[self.pc]
+            operand_a = self.ram_read(self.pc+1)
+            operand_b = self.ram_read(self.pc+2)
+            if instruction_to_excecute == LDI:
+                self.reg[operand_a] = operand_b
+                self.pc += self.num_of_operands(instruction_to_excecute)
+            elif instruction_to_excecute == PRN:
+                reg = self.reg[operand_a]
+                print (reg)
+                self.pc += self.num_of_operands(instruction_to_excecute)
+            elif instruction_to_excecute == HLT:
+                self.running = False
+                self.pc += self.num_of_operands(instruction_to_excecute)
+            elif instruction_to_excecute == MUL:
+                self.alu(instruction_to_excecute,operand_a,operand_b)
+                self.pc += self.num_of_operands(instruction_to_excecute)
+            elif instruction_to_excecute == PUSH:
+                self.reg[SP] -=1 # decrement the stack pointer
+                self.ram_write(self.reg[operand_a],self.reg[SP])
+                self.pc += self.num_of_operands(instruction_to_excecute)
+            elif instruction_to_excecute == POP:
+                self.reg[operand_a] = self.ram_read(self.reg[SP])
+                self.reg[SP]+=1
+                self.pc += self.num_of_operands(instruction_to_excecute)
+            elif instruction_to_excecute == CALL: 
+                self.reg[SP]-=1
+                addr_of_next_inst = self.pc+2
+                self.ram_write(addr_of_next_inst,self.reg[SP])
+                reg_to_get_addr_from = operand_a
+                jump_to_addr = self.reg[reg_to_get_addr_from]
+                self.pc = jump_to_addr
+            elif instruction_to_excecute == RET:
+                addr_to_return = self.ram_read(self.reg[SP])
+                self.pc = addr_to_return
+                self.reg[SP]+=1
+            elif instruction_to_excecute == JMP:
+                self.pc = self.reg[operand_a]
+            elif instruction_to_excecute == CMP:
+                if self.reg[operand_a]>self.reg[operand_b]:
+                    self.fl = 0b00000010
+                elif self.reg[operand_a]<self.reg[operand_b]:
+                    self.fl = 0b00000100
+                else:
+                    self.fl = 0b00000001
+                self.pc += self.num_of_operands(instruction_to_excecute)
+            elif instruction_to_excecute == JNE:
+                if self.fl != 0b00000001:
+                    self.pc = self.reg[operand_a]
+                else:
+                    self.pc += self.num_of_operands(instruction_to_excecute)
+            elif instruction_to_excecute == JEQ:
+                if self.fl == 0b00000001:
+                    self.pc = self.reg[operand_a]
+                else:
+                    self.pc += self.num_of_operands(instruction_to_excecute)
+            else:
+                print ("idk what to to")
+                sys.exit()
+
+
+   
+        
diff --git a/ls8/lecture.py b/ls8/lecture.py
new file mode 100644
index 000000000..21cf13731
--- /dev/null
+++ b/ls8/lecture.py
@@ -0,0 +1,112 @@
+import sys
+
+# machine that excecutes an instruction
+
+# op-code - represent the instruction that is supposed to be executed 
+PRINT_HI = 1
+HALT = 2
+PRINT_NUM = 3
+SAVE = 4 # SAVE a val in reg
+PRINT_REGISTER = 5
+ADD = 6 #takes 2 reg A and B, adds both and stores in reg A
+PUSH = 7 # takes in a register and stores a val in that reg on top of a stack 
+POP = 8  # takes in a register and stores topmost element in the stack in it.
+CALL =9
+RET = 10
+PRINT_SUBROUTINE = 11  
+
+def load_memory():
+    program = [
+        PRINT_HI,
+        SAVE, # save val 65 in reg 2 
+        7,
+        2,
+        CALL,
+        2,
+        HALT,
+        PRINT_SUBROUTINE,
+        SAVE,
+        500,
+        0,
+        RET
+    ]
+    space_for_stack = 128 - len(program)
+    memory = program + [0] * space_for_stack
+    return memory
+
+memory = load_memory()
+
+registers = [0] * 8 #8 registers
+stack_pointer_register = 7
+registers[stack_pointer_register] = len(memory)-1 #address of stack pointer
+
+program_counter = 0 # points to curr inst we need to execute next 
+running = True 
+
+#keep looping while not Halted
+
+while running:
+    command_to_execute = memory[program_counter]
+
+    if command_to_execute == PRINT_HI:
+        print("hi")
+        program_counter+=1
+    elif command_to_execute == PRINT_NUM:
+        number_to_print = memory[program_counter +1]
+        print(f"{number_to_print}")
+        program_counter+=2
+    elif command_to_execute == SAVE:
+        value_to_save = memory[program_counter+1]
+        register_to_save_it_in = memory[program_counter+2]
+        registers[register_to_save_it_in] = value_to_save
+        program_counter+=3
+    elif command_to_execute == PRINT_REGISTER:
+        register_to_print = memory[program_counter+1]
+        print(f"{registers[register_to_print]}")
+        program_counter +=2
+    elif command_to_execute == ADD:
+        register_a = memory[program_counter+1]
+        register_b = memory[program_counter+2]
+        sum_of_reg = registers[register_a]+registers[register_b]
+        registers[register_a] = sum_of_reg
+        program_counter +=3
+    elif command_to_execute == HALT:
+        running = False
+        program_counter+=1
+    elif command_to_execute == PUSH:
+        registers[stack_pointer_register] -=1 # decrement stack pointer
+        register_to_get_value_in  = memory[program_counter+1]
+        value_in_register = registers[register_to_get_value_in]
+        memory[registers[stack_pointer_register]] = value_in_register
+        program_counter +=2
+    elif command_to_execute == POP:
+        register_to_pop_value_in = memory[program_counter+1]
+        registers[register_to_pop_value_in] = memory[registers[stack_pointer_register]]
+        registers[stack_pointer_register]+=1 
+        program_counter+=2
+    elif command_to_execute == PRINT_SUBROUTINE:
+        print('I am in a SubRoutine')
+        program_counter+=1
+    elif command_to_execute == CALL:
+        #Takes in a register and stores address of next instruction on top of stack
+        # it jumps to address stored in that register
+        registers[stack_pointer_register] -=1
+        address_of_next_inst = program_counter+2
+        memory[registers[stack_pointer_register]] = address_of_next_inst
+        register_to_get_addr_from = memory[program_counter+1]
+        program_counter = registers[register_to_get_addr_from]
+    elif command_to_execute == RET:
+        # pops top element of stack and sets PC to it 
+        # does not take any operand 
+        program_counter = memory[registers[stack_pointer_register]]
+        registers[stack_pointer_register]+=1 
+    else:
+        print("unknown instruction {command_to_execute}")
+        sys.exit(1)
+
+print (registers)
+print (memory)
+
+
+
+
diff --git a/ls8/ls8.py b/ls8/ls8.py
index 74128d36b..c6208432e 100755
--- a/ls8/ls8.py
+++ b/ls8/ls8.py
@@ -7,5 +7,10 @@
 
 cpu = CPU()
 
-cpu.load()
-cpu.run()
\ No newline at end of file
+filename = sys.argv[1]
+cpu.load(filename)
+cpu.run()
+
+
+
+