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Configure puter was the ENIAC (Electronic Numerical Integrator and Calculator), which was built for the U.S. Army in 1946, largely because of the need to calculate ballistics tables. The ENIAC was programmed by plugging in cables to connect different units. In 1945 John von Neumann intro- duced the modern concept of a stored-program computer, in [...]

Conceptually a computer system is made up of layers. The hardware is the lowest level in all such systems. The kernel running at the next level uses the hardware instructions to create a set of system call for use by outer layers. The system programs above the kernel are therefore able to use either system [...]

The region in the memory that a process is allowed to access is known as process address  space. To ensure correct operation of a computer system, we need to ensure that a process cannot access memory outside its address space. If we don’t do this then a process may, accidentally or deliberately, overwrite the address [...]

Multi-programming put several programs in memory at the same time; while this increased system utilization it also increased problems. With sharing, many processes could be adversely affected by a bug in one program. One erroneous program could also modify the program or data of another program or even the resident part of the operating system. [...]

We need simply three constructs to solve any problem. 1) Things should be executed sequentially. That means the statements are executed in a sequence i.e. the second statement follows the first and so on. 2) We need to have a decision. The decision means if something is true, the program executes it. Otherwise, it tries [...]

Templates are a major code reuse feature. History of C++ language reveals that the template feature was introduced later, relative to other features. But it is a very important feature. We will realize that it makes a lot more sense to keep total code base very small and very concise. It also helps ensure that [...]

Now let’s talk about the implications of the template classes. To understand the behavior of templates with static members, we have to comprehend the concept of static member variables. Static variable members are used to define ordinary classes. The static variable has a single copy for the whole class. So there are not separate copies [...]

After discussing functions and playing little bit with function calling, we had elaborated the concept of Arrays. As discussed previously in this lecture, arrays are used to aggregate variables of same data type. We wrote little functions about it and did some exercises e.g., when we wanted to store age of students of our class. [...]

We have so far been dealing with bytes using different data types. In this lecture, we will see what a bit is? Bit is the basic unit of memory. Eight bits form a byte. As you know that data is stored in computers in 0’s and 1’s form. An integer uses four bytes and the [...]

In general, we should minimize the use of break statement in loops. The switch statement is an exception in this regard where it is necessary to use the break statement after every case. Otherwise, there may be a logical error. While writing loops, we should try to execute the loops with the condition test and [...]