Operation System

OS

An operating system (OS) is a collection of software that manages computer hardware resources and provides common services for computer programs. The operating system is an essential component of the system software in a computer system. Application programs usually require an operating system to function.The operating system acts as an interface between the hardware and the programs requesting I/O. It is the most fundamental of all system software programs.
Responsibilities of the OS include:

• Hiding the complexities of hardware from the user

• Managing between the hardware's resources which include the processors, memory, data storage and I/O devices

• Handling "interrupts" generated by the I/O controllers

• Sharing of I/O between many programs using the CPU

The most well known Operating Systems include:

• System Software - programs that manage the operation of a computer

• Application Software - programs that help the user perform a particular task

User InterfacesThe User Interface is the interaction between the User and the Machine, letting the user send commands with the expected results. Two forms of the Interface User are the Command Line Interface and the Graphical User Interface.


Memory management is the act of managing computer memory. The essential requirement of memory management is to provide ways to dynamically allocate portions of memory to programs at their request, and free it for reuse when no longer needed. This is critical to any advanced computer system where more than a single process might be underway at any time.

Process management is the ensemble of activities of planning and monitoring the performance of a process. The term usually refers to the management of business processes and manufacturing processes. Business process management (BPM) and business process reengineering are interrelated, but not identical.

In computer science, scheduling is the method by which threads, processes or data flows are given access to system resources (e.g. processor time, communications bandwidth). This is usually done to load balance a system effectively or achieve a target quality of service. The need for a scheduling algorithm arises from the requirement for most modern systems to perform multitasking (execute more than one process at a time) and multiplexing (transmit multiple flows simultaneously).
--The scheduler is concerned mainly with:
--Throughput - The total number of processes that complete their execution per time unit.
--Latency, specifically:
--Turnaround time - total time between submission of a process and its completion.--
--Response time - amount of time it takes from when a request was submitted until the first response is produced.

--Fairness / Waiting Time - Equal CPU time to each process (or more generally appropriate times according to each process' priority). It is the time for which the process remains in the ready queue.

An instruction cycle (sometimes called fetch-and-execute cycle, fetch-decode-execute cycle, or FDX) is the basic operation cycle of a computer. It is the process by which a computer retrieves a program instruction from its memory, determines what actions the instruction requires, and carries out those actions. This cycle is repeated continuously by the central processing unit (CPU), from bootup to when the computer is shut down.

Each computer's CPU can have different cycles based on different instruction sets, but will be similar to the following cycle:

1. Fetching the instruction

The next instruction is fetched from the memory address that is currently stored in the program counter (PC), and stored in the instruction register (IR). At the end of the fetch operation, the PC points to the next instruction that will be read at the next cycle.

2. Decode the instruction

The decoder interprets the instruction. During this cycle the instruction inside the IR (instruction register) gets decoded.

3.In case of a memory instruction (direct or indirect) the execution phase will be in the next clock pulse.

If the instruction has an indirect address, the effective address is read from main memory, and any required data is fetched from main memory to be processed and then placed into data registers(Clock Pulse: T3). If the instruction is direct, nothing is done at this clock pulse. If this is an I/O instruction or a Register instruction, the operation is performed (executed) at clock Pulse.

4. Execute the instruction

The control unit of the CPU passes the decoded information as a sequence of control signals to the relevant function units of the CPU to perform the actions required by the instruction such as reading values from registers, passing them to the ALU to perform mathematical or logic functions on them, and writing the result back to a register. If the ALU is involved, it sends a condition signal back to the CU.

Von Neumann Architecture

Computer data storage, often called storage or memory, is a technology consisting of computer components and recording media used to retain digital data. It is a core function and fundamental component of computers. The central processing unit (CPU) of a computer is what manipulates data by performing computations. In practice, almost all computers use a storage hierarchy, which puts fast but expensive and small storage options close to the CPU and slower but larger and cheaper options farther away. Often the fast, volatile technologies (which lose data when powered off) are referred to as "memory", while slower permanent technologies are referred to as "storage", but these terms can also be used interchangeably. In the Von Neumann architecture, the CPU consists of two main parts: control unit and arithmetic logic unit (ALU). The former controls the flow of data between the CPU and memory; the latter performs arithmetic and logical operations on data.
Input is the term denoting either an entrance or changes which are inserted into a system and which activate or modify a process. It is an abstract concept, used in the modeling, system design and system exploitation. It is usually connected with other terms, e.g., input field, input variable, input parameter, input value, input signal, input port, input device and input file.

Output is the term denoting either an exit or changes which exit a system and which activate/modify a process. It is an abstract concept, used in the modeling, system(s) design and system(s) exploitation.

A central processing unit (CPU), also referred to as a central processor unit, is the hardware within a computer that carries out the instructions of a computer program by performing the basic arithmetical, logical, and input/output operations of the system. The term has been in use in the computer industry at least since the early 1960s. The form, design, and implementation of CPUs have changed over the course of their history, but their fundamental operation remains much the same.

An arithmetic and logic unit (ALU) is a digital circuit that performs integer arithmetic and logical operations. The ALU is a fundamental building block of the central processing unit of a computer, and even the simplest microprocessors contain one for purposes such as maintaining timers. The processors found inside modern CPUs and graphics processing units (GPUs) accommodate very powerful and very complex ALUs; a single component may contain a number of ALUs.

ICT LOGIC GATES

A logic gate is an idealized or physical device implementing a Boolean function, that is, it performs a logical operation on one or more logical inputs, and produces a single logical output. Depending on the context, the term may refer to an ideal logic gate, one that has for instance zero rise time and unlimited fan-out, or it may refer to a non-ideal physical device^[1] (see Ideal and real op-amps for comparison).

Logic gates are primarily implemented using diodes or transistors acting as electronic switches, but can also be constructed using electromagnetic relays (relay logic), fluidic logic, pneumatic logic, optics, molecules, or even mechanical elements. With amplification, logic gates can be cascaded in the same way that Boolean functions can be composed, allowing the construction of a physical model of all of Boolean logic, and therefore, all of the algorithms and mathematics that can be described with Boolean logic.

Logic circuits include such devices as multiplexers, registers, arithmetic logic units (ALUs), and computer memory, all the way up through complete microprocessors, which may contain more than 100 million gates. In practice, the gates are made from field-effect transistors (FETs), particularly MOSFETs (metal–oxide–semiconductor field-effect transistors).

Compound logic gates AND-OR-Invert (AOI) and OR-AND-Invert (OAI) are often employed in circuit design because their construction using MOSFETs is simpler and more efficient than the sum of the individual gates.^[2]

Google Car

(Google Self-Driving Car image by Steve Jurvetson, CC BY 2.0)

After several years of testing autonomous car, Google has revealed something to show for its work. It’s been proven before that Google’s autonomous vehicles are actually safer than car driven by an actual person. and now, the proof has been furthered, after a few test in California and Nevada.

Major Concepts

• The new car runs on battery and can be charged
• It has it's own brain that can control all of it's surroundings
• It is able to navigate through tight traffic using radar system

Advantage

• It is far more safer than human driven cars because it uses technology.
• it can reduce risk of accidents/ drunk driving  because it goes in a steady pace.
• good for people who aren't able to drive because it it an automatic car.

Disadvantage

• This car is really slow because it doesn't have a huge engine
• This car is highly expensive and can be bought only by rich people because it is new and it's it at the moment limited.
• it doesn't have the capability to pick up speed to over take because it is slow.

Discussion Questions

Why do you think people will use this car?

Can this reduce the number of accidents in this world ?

Starr, Michelle. “Google: Self-driving Cars Safer than Professional Drivers.” - Cars. Cnet, 28 Oct. 2013. Web. 31 Oct. 2013.