What is Personal Computer? History of Personal Computer
A personal computer is also known as a PC is a type of microcomputer designed in principle to be used by only one person at a time. It is generally medium in size and is used by a single user (although there are operating systems that allow multiple users simultaneously, which is known as multi-user).
A personal computer is usually equipped to accomplish common tasks of modern computing, i.e. it allows users to surf the Internet, write texts and perform other office or educational tasks, such as editing texts and databases. In addition to relaxing activities such as listening to music, watching videos, playing games, and studying, etc.
The first PC is the Programma 101, produced by the Italian company Olivetti between 1962 and 1964. The personal computer invented by the Italian engineer Pier Giorgio Perotto who was also the inventor of the magnetic card. Programma 101 was also used: in 1969 by NASA to send a man to the Moon on the Apollo 11 mission; on the American television channel ABC to predict the 1969 political elections; by American soldiers to plan the operation in the Vietnam War. In 1968, Hewlett Packard created a PC almost identical to Programma 101. The Hewlett-Packard 9100A and was found guilty of plagiarism and paid for reimbursement to Olivetti.
It was the launch of the VisiCalc spreadsheet, initially for the Apple II and later for the IBM PC, the application that managed to turn the microcomputer into a work tool. The low cost of personal computers made it very popular with both families and workers in the 1980s. It was much less versatile and powerful than corporate computers at the time and was generally used for gaming by computer hobbyists.
In the 1990s, the power of personal computers increased dramatically, blurring the outdated boundary between personal computers and multi-user computers such as mainframes. Today, high-end computers are distinguished from personal computers by their greater reliability or their greater ability to multitask and not by the power of the CPU.
Most personal computers use a hardware architecture compatible with the IBM PC, using x86 compatible processors made by Intel, AMD, or Cyrix.
Despite the enormous popularity of the personal computer, several IBM-incompatible microcomputers (also generally called personal computers) are still popular for certain specific uses. The main alternative, until recently, was the computer with a PowerPC processor, with Apple Computer’s Mac OS X operating system (although other operating systems can run on this architecture), which is used mainly for graphic design and related uses, serving also perfect for a home user. It must be said that as of 2006 Apple computers use Intel microprocessors and PowerPCs are no longer manufactured. Despite this, they are still incompatible (compatible ones use BIOS and Mac EFIs).
The personal computer is in a user-friendly word for the second generation of desktop computers, which entered the market in 1977 and became in common use during the 1980s. They are also known as personal computers.
The personal computer became readily available to the general public due to the mass production of the microprocessor based on the silicon chip and as the name suggests, intended to be used in the home rather than in business/industrial settings. They were also designed to be immediately useful to non-technical customers, in contrast to the first generation microcomputers that came as kits and often required electronics skills. The use of the term “personal computer” largely died out towards the end of the decade (in the US) or in the early 1990s (in Europe). This was due to the emergence of the IBM PC compatible personal computer, and the consequent preference for the term “PC” over “the personal computer.”
Notable Personal Computers:
The list below shows the most popular and historically significant personal computers from the past years since the 1970s.
The technologies used in digital computers have evolved greatly since the appearance of the first models in the 1940s, although most still use the von Neumann Architecture, published by John von Neumann in the early 1940s, which other authors attribute to John Presper Eckert and John William Mauchly.
The Von Neumann architecture describes a computer with four main sections: the arithmetic logic unit, the control unit, the primary, main, or central memory, and the input and output (I / O) devices. These parts are interconnected by conductor channels called buses.
Central Processing Unit (CPU)
The Central Processing Unit (CPU) basically consists of the following three elements:
The Arithmetic-Logic Unit (ALU) is the device designed and built to carry out elementary operations such as arithmetic operations (addition, subtraction, …), logical operations (AND, OR, NO), and comparison of relational operations. This unit is where all the computational work is done.
The control unit (CU) follows the address of the memory positions that contain the instruction that the computer is going to carry out at that moment. It recovers the information by putting it in the ALU for the operation to be carried out. Then transfer the result to appropriate locations in memory. Once this occurs, the control unit goes to the next instruction (usually located in the next position, unless the instruction is a jump instruction, informing the computer that the next instruction will be located in another position in the memory).
Primary memory (PM), known as Random Access Memory (RAM), is a sequence of numbered storage cells, each one being a bit or unit of information. The instruction is the information necessary to do what you want with the computer. The “cells” contain data that is needed to carry out the instructions, with the computer. The number of cells varies greatly from computer to computer, and the technologies used for memory have changed considerably; ranging from electromechanical relays, mercury-filled tubes in which acoustic pulses were formed, permanent magnet arrays, individual transistors to integrated circuits with millions of cells on a single chip are subdivided into static memory (SRAM) with six transistors per bit and the much more widely used dynamic memory (DRAM) one transistor and one capacitor per bit. In general, memory can be rewritten several million times (RAM memory); it looks more like a blackboard than a tombstone (ROM memory) that can only be written once.
Entry, Exit Peripherals
The Input /Output (I/O) devices serve the computer to obtain information from the outside world and/or communicate the results generated by the computer to the outside. There is a very wide range of I/O devices such as keyboards, monitors, floppy drives, or webcams.
There are three basic units in a computer:
The CPU, the RAM, and the I/O subsystem, are communicated with each other by buses or communication channels:
Address bus, to select the address of the data or peripheral to be accessed.
Control bus, basically to select the operation to be carried out on the data (mainly reading, writing, or modification) and Databus, where the data circulates.
Software is a general term used to describe a collection of computer programs, procedures, and documentation that perform some tasks on a computer’s system. The term includes application software, such as word processors that perform productive tasks for users; system software, such as operating systems, that interface with hardware to provide the services necessary for application software, and middleware that control and coordinate distributed systems.
An operating system (OS) manages computer resources and provides programmers with an interface that is used to access those resources. An operating system processes system data and user input and response by assigning and managing internal system resources and tasks as a service to system users and programs. An operating system performs basic tasks such as memory allocation and control, prioritizing system requests, input and device control, facilitating computer networking, and managing output files.
Common contemporary desktop operating systems are Microsoft Windows (90.65% market share), Mac OS X (7%), Linux (0.95%), Solaris, and FreeBSD. Windows, Mac, and Linux all have server and personal variants. With the exception of Microsoft Windows, the designs of each of the aforementioned operating systems were inspired by or directly inherited, the UNIX operating system. UNIX was developed at Bell Labs in the late 1960s and encourages the development of many free and proprietary operating systems.