The computer has been passed many generations before coming up to the state of computer, laptop, desktop and notebook form. At first initial phase, Blaise Pascal gave the birth of a mechanical calculator(counting device) in 1642 AD and then in around 1830 AD, Charles’s Babbage developed “difference engine” and ” Analytical engine”. After that many evolutions happened, such as the use of vacuum tube, transistor, integrated circuits etc. This step up in technology is called generations of computer. The generation of a computer has been categorized into first, second, third, fourth and fifth generations based on the key evolutions(vacuum tube, transistor, IC) from past time to recent time.
Fourth generation computers:
All the computers which came into existence in the mid 1970s and being used today are fourth generation computers. example of some of the fourth generation of computers are: power pc, UltraSparc and all modern pcs The main features of the fourth generation computers are as follows:
- Fourth generation computers use ULSI(ultra large scale of integration) chips for CPU, memory and other supporting chips.
- They use a microprocessor as a CPU. The microprocessor is of32 and 64 bits. Their clock frequency lies in the range of 400-1000MHZ. Nowadays the clock frequency of the processor is in gigahertz.
- Beside CPU, the fourth generation computers also contain many other essential components such as MMU (memory management unit), first level and second level cache memory, FPU(floating point unit) etc.
- Use of RISC(reduced instruction set computers) makes the fourth generation computers more powerful.
- Main memories of 256 MB, 512MB,1GB,4GB,8GB are available today.
- Magnetic disks(such as a hard disk), optical disks(such as CDROM, CDRW, DVD etc. ) are used as secondary memory.
- In a multimedia system input and output in the form of text, graphics, images and sound are used.
- Procedure-oriented and object-oriented programming languages were developed.
- Very special language called 4GL(4th generation languages) such as ORACLE, SYBASE etc are used for database management.
- Advanced operating systems such as Linux, Windows Unix etc.
- eg: power pc, UltraSpark and all modern pcs.
difference between the third generation and fourth generation computers:
|Third generation computer||Fourth generation computer|
They used ICs(integrated circuits) for CPU components.
They used ULSI(ultra large scale of integration) chips for CPU, memory and other supporting chips.
Magnetic disks and magnetic tapes were used as secondary memories.
Magnetic disks(such as a hard disk), optical disks(such as CDROM, CDRW, DVD etc. ) are used as secondary memory.
Advanced high level language such as c was developed for computer programming.
Procedure-oriented and object-oriented programming languages were developed.
|4||They consume more power then fourth generation computer||Power consumption is very less|
|5||They are less powerful then fourth generation computer||They are more powerful|
|6||They were comparatively larger computers||Size comparatively smaller|
The example of third generation computers are: IBM/370 Series, CDC7600, PDP11, STAR-100 etc.
eg: power pc, UltraSpark and all modern pcs.