Computer coding: The basics.
The process of programming should not be confused with the real code residing on the computer. Programming is the process of generating the code . The code is than stored on a storing device and activated or read when necessary.
The real code that controls the hardware consists of a series of "1's" or "0's". This code either resides in the ROM (Read Only Memory ) on chips or on a disk ( floppy, stuffy, hard or CD). The "1's" represent an open switch, a wire with current, an area in a chip with high voltage, an area on a magnetic disk with a magnetic field, an area reflecting light on a laser disc etc. The "0's" represent a closed circuit, absence of current, low voltage on a chip , no polarized magnetic activity or no light reflection. A computer only counts to 2. (0 and 1) In the everyday decimal system we count to 10 (0 - 9)
A "0" or a "1" are referred to as bits and eight bits is a byte. A byte is usually the equivalent of one instruction.
Each of the four bytes in the example will cause the computer to do something. All modern computers function on this code, even the complicated client server systems that make it possible for this article to be read anywhere in the world. All modern microchips are programmed in this code. Your cell phone, your automatic washing machine , the fuel injection system in your automobile and most appliances are controlled via binary code that reside in micro chips. All these micro chips contain computer programs programmed by human programmers.
The binary code is responsible for what is known as digital in electronic circles. This is in contrast to the term analogue. Analogue devices compare different values ( ex voltage differences) and obtain values according to the differences. Digital devices uses digits to operate and usually in a binary form (a "0" or a "1"). Most modern electronic equipment are digital devices.
What is the difference between 8 bit, 16 bit, 34 bit and 64 bits?
It refers to the rate data is moved through the system. One byte equals 8 bits . A 16 bit system will move 2 bytes simultaneously and 32 bit system will move 4 bytes of information simultaneously. Most modern computers are 32 bit systems but we are moving in the direction of 64 bit systems. (moving 8 bytes simultaneously0) The next step will be 128 bit systems ( moving 16 bytes simultaneously). A very simple way to explain the difference between digital and analogue devices is to used sound systems as an example. The out dated long playing records had a groove cut into the record. The bottom of the groove was uneven and as the head of the record player moved through the grove as the record turns at a preset speed, thus unevenness created frequencies similar to the frequency present when the record was originally cut. An exact replica of the recorded sound is than produced. The variations in the depth of the groove is an analogue system. A laser disc player resembles a record player but it is a digital system. The disc contains areas that reflect light and areas that do not. The light reflections open circuits while the areas that doesn't reflect light cause them to remain close.
There are different digital systems . We are all familiar with the decimal system with 10 digits(0,1,2,3,4,5,6,7,8,0r 9). Other digital systems are the binary system with 2 digits(0 and 1) with 8 digits (0,1,2,3,4,5,6 and 7) and with 16 digits(0,1,2,3,4,5,6,7,8,9,A,B,C,D,E AND F)
The binary , octal and hexa l systems are all important in digital computer programming.
When you start your computer the micro chips in the so called ROM (read only memory) generate code ("0's" and "1's" ) that starts the computer , activates it basic I/S O/S systems ( input /output systems) and than loads the operating system ( Windows, Linux, Unex, MacOs, etc.)
The operating systems are programs and also consists of "0's" and "1's". The operating systems organize the the the whole computer, make it possible for the different programs (spread sheets, word processors, games, data bases etc) and hardware (the computer, keyboard, screen, printers, scanners , modems etc,) to communicate and to function as a unit. The different versions of Windows is a well known operating system. Unix , Linux, MacOs, JavaOs, are other examples.
The operating system is usually stored on the computer's hard disk. The ROM chips give the order to load the operating system. .Every type of hardware (keyboards, screens, printers, scanners, modems etc.) are controlled by drivers. Drivers are programs that allow the different hardware to communicate and function as a unit. Each specific type of operating system needs drivers written for that specific system ( or platform). It needs a driver for every piece of hardware connected to the computer. The printers , scanners, keyboards, modems etc each need a specific driver. The drivers are only compatible with a specific operating system. If you change or update your operating system , you will need new drivers.