TICO

TICO

A central processing unit is the electronic circuitry within a computer that executes instructions that make up a computer program. They all perform basic arithmetic, logic, controlling and input/ output operations. The fundamental operation of most CPUs is to execute a sequence of stored instructions. The speed on a processor depends on the clock rate; generally given in multiples of Hertz. The hertz is the unit of frequency in the International system and is defined as one cycle per second. Performance is increased by using multi-core processors; it increases the workload that can be handled.

Random-access memory is a form of computer memory that can be read and changed in any order. Stored information is lost if power is removed.

SRAM: lower access time is faster; more expensive; requires a constant power supply; less storage capacity.

DRAM: higher access time is slower; cheaper; reduced power consumption because the information is stored in the capacitor; large storage capacity.

It is important to have enough capacity in your ram (GB) in order that you can handle all the programs you need simualteneously.

A hard disk drive is a non volatile data storage device. It is usually installed in a computer, attached directly to the disk controller of the computer's motherboard. A hard drive can store any data. They have a storage size of terabytes.

A cache is a reserved storage location that collects temporary data to help websites, apps and browsers load faster. It acts like a memory bank, making it easy to access to data instead of redowloading it every time we visit a website or open an app. Cache's are found in CPU's, websites and apps in order to make them function faster and to remenber the data.

Von Neumann architecture was first published by John von Neumann in 1945.

His computer architecture design consists of a Control Unit, Arithmetic and Logic Unit (ALU), Memory Unit, Registers and Inputs/Outputs.

Let's start from the beginning, there are three types of information:

-Control information: it is a direct order. Makes something to do something. What to do?

-Adress Information: a location. Where?

-Data information: contents of something.

It is important to know that instruction data and program data are stored in the same memory.

As we have said, we have three elements the Cpu, the Ram and Inputs/Outputs. These elements are connected with wires, also called buses.

The Central Processing Unit (CPU) is the electronic circuit responsible for executing the instructions of a computer program. 

The CPU is formed of several things:

-Registers are high speed storage areas in the CPU. All data must be stored in a register before it can be processed. 

It does several things: holds the memory location of data that needs to be accessed; holds data that is being transferred to or from memory; where intermediate arithmetic and logic results are stored; contains the address of the next instruction to be executed and contains the current instruction during processing.

-The ALU allows arithmetic and logic operations to be carried out.

-The control unit controls the operation of the computer telling  how to respond to the program instructions it has just read and interpreted from the memory unit.

The memory unit consists of RAM, sometimes referred to as primary or main memory.  Unlike a hard drive (secondary memory), this memory is fast and also directly accessible by the CPU.

RAM is split into partitions.  Each partition consists of an address and its contents (both in binary form).

The address will uniquely identify every location in the memory.

Loading data from permanent memory (hard drive), into the faster and directly accessible temporary memory (RAM), allows the CPU to operate much quicker.

Buses are the means by which data is transmitted from one part of a computer to another, connecting all major internal components to the CPU and memory.

Address bus: Carries the addresses of data (but not the data) between the processor and memory.

Control bus: Carries control signals/commands from the CPU (and status signals from other devices) in order to control and coordinate all the activities within the computer.

Data bus: Carries data between the processor, the memory unit and the input/output devices.

The information can leave and reach one of the main components.

MACHINE LANGUAGE

Los comandos tienen asociados una combinación de o y 1. Cada palabra tiene asociada una combinación de números.        Eject: 10110101-action.                                                                                                                                                                                        USB: 10110101-object.

The context and the thing that is referring to matters. An action and an object can have the same number, this is because they refer to different things. 

The binary numbers are called bits. (Binary digit). Words are associated to numbers. 1 digit is 1 bit.

Machine code: tenemos que elevar 2 al número de bits. Ese es el número de combinaciones y el número de dígitos. Cuántos más bits, más palabras.

Los ordenadores antiguamente tenían 8 bits. 1 word- 1 byte- 8 bits- 2 elevado a 8

2 elevado a 8 palabras distintas y acciones. Un ordenador podía hacer 256 cosas distintas. Eso es muy poco.

32bit- 2 elevado a 32- Windows.

64bit-2 elevado a 64- windows, osx, linux, unix.

Una tabla para acciones y otra para objetos. Assembler language.

The assembler language tiene una relación directa con el machine language.

Más bits-más palabras-más rápido.

Los sistemas oeprativos se programan en el assembler language.

OPERATING SYSTEMS

Everything we have except the program. Program are especifically designed to run with the operating system.

To provide a working environment. Create a folder structure. Recognize hardware. Copying/Deleting. Desktop. Allow to install applications.

Main operating systems: MS-DOS/ WINDOWS/ LINUX/ OSX

Multitask: several tasks.

Multiuser: several logins.

Plug and Play: enchufar una cosa y que funcione. Ex: usb.

Freeware: is free.

Opensource: upload the code and the program.

Defragmentation, also known as “defrag” or “defragging” is the process of reorganizing the data stored on the hard drive so that related pieces of data are put back together, all lined up in a continuous fashion.  You could say that defragmentation is like cleaning house for your server or PC, it picks up all of the pieces of data that are spread across your hard drive and puts them back together again.

Why is defragmentation important? Because every computer suffers from the constant growth of fragmentation and if you don’t “clean house”, your servers and PCs suffer.

Disk fragmentation occurs when a file is broken up into pieces to fit on the disk. Because files are constantly being written, deleted and resized, fragmentation is a natural occurrence. When a file is spread out over several locations, it takes longer to read and write. 

The more physically fragmented a file, the more work the disk drive has to do, and disk I/O performance is hurt. The second condition causes problems when data is being written to disk. It is faster to write contiguous data than noncontiguous data scattered over a drive or array.

File system: