Research at least three computer architecture models. Differentiate each with the Von Neumann Model.

This architecture basically serves the Turing machine very well. The Turing machine is a bit more of a philosophical model, whereas the von Neumann architecture is a specification for the implementation of one. The CPU here is a serial processor unit which, in any way you put it, never executes more than one instruction at any given time, or per clock cycle. The CPU then has a couple of pins available that are connected to outside devices or buses. Sometimes the buses don't really contain anything, but you could put some PCI, PCIe, ISA or other kinds of electronics in them, or you could attach some device to a serial, parallel, USB or FireWire port and then the more advanced Operating Systems would allow the automatic registration of these devices and subsequent allocations of address spaces and such (through a driver and hardware-specific communication protocol like USB has).

The CPU is connected to the various other components of the computer by buses, which are a set of wires forming connections.

Even when the computer seems to be idle, lots is going on. Millions of interchanges are happening between the components, passing along a data highway called the bus. Various input/output controllers work with the CPU to ensure that all this traffic is regulated in an orderly way, so that the PC does not crash. The bus transports the data between the CPU and the other components. It is a ribbon connector, part of the motherboard. However we cannot look at the motherboard to point out the bus; it is a complex arrangement of circuits that are printed on top of and below the motherboard. These circuits are called traces.

Comparison of Harvard and Von Neumann Architectures

In Harvard architecture, the data bus and address bus are separate. Thus a greater flow of data is possible through the central processing unit, and of course, a greater speed of work. Separating a programme from data memory makes it further possible for instructions not to have to be 8-bit words. For example the Microchip PIC16F84 microcontroller uses 14 bits for instructions which allows for all instructions to be one word instructions. It is also typical for Harvard architecture to have fewer instructions than Von-Neumann's, and to have instructions usually executed in one cycle.

Microcontrollers with Harvard architecture are also called Reduced Instruction Set Computer (RISC) microcontrollers. Microprocessors with Von-Neumann's architecture are called Complex Instruction Set Computers (CISC).