Hardware Simulation and Modeling is new way to demonstrate the complex operations of MIPS CPU in freeware simulator software Logisim,this book will help to know in detail about Logic gates AND,OR,XOR,NAND and NOT in unique way of implementation in C language,Binary Arithmetic operations Addition,Subtraction, Multiplication and Division algorithms coded in C language. in Logisim simulate Half Adder, Full Adder by using sub circuit to develop 4-bits,32 bits Adders which further use in 1-Bit ALU and 32-bits ALU. Implantations of different sizes of Muxes,Encoders and Decoders with the help of logic gates, this book is an easy approach to construct all the components of ALU and Control unit from the Scratch to build complex MIPS CPU ARCHITECTURE Datapaths. MIPS CPU ARCHITECTURE Datapaths is difficult to understand because it consist of many components such as PC, Instructions Set, Data Memory,32 bits ALU,ALU control unit. This book will guide how easily these components can design with Logisim to make easy understanding for the students.