What are memory mapped I/O and isolated I/O? What are differences between memory mapped I/O and isolated I/O?

Memory Mapped I/O and Isolated I/O are two methods of performing input-output operations between CPU and installed peripherals in the system. 

Memory Mapped I/O:

Memory mapped I/O uses the same address bus to connect both primary memory and memory of hardware devices (registers). Memory and registers of I/O devices gets assigned values, thus when CPU try to access an address value, it can either from memory or from registers of I/O devices. Memory mapped I/O thus helps in utilizing the same instruction for accessing or addressing both primary memory and I/O device memory locations. 

What are time sharing and real time systems? What are the differences between time sharing and real time systems?

Time-Sharing Systems:

Time sharing operating systems are extension of multiprogrammed batched operating system and the extension is that here the user can interact with the program running. The CPU scheduling algorithm and allocate small amount time to each job at once and then move on to the next job. Thus the user can get output from the program and can input another command and wait for the output. Keyboard is used to input command and monitors are for output. A time sharing operating system allows many user to use the same computer at the same time such as every user is using his own computer. This is achieved by frequently switching from one program to another and satisfying users with an output from the program before switching to the next one.

What are time sharing and multiprogrammed batched systems? What are the differences between time sharing and multiprogrammed batched systems?

Time-Sharing Systems:

Time sharing operating systems are extension of multiprogrammed batched operating system and the extension is that here the user can interact with the program running. The CPU scheduling algorithm and allocate small amount time to each job at once and then move on to the next job. Thus the user can get output from the program and can input another command and wait for the output. Keyboard is used to input command and monitors are for output. A time sharing operating system allows many user to use the same computer at the same time such as every user is using his own computer. This is achieved by frequently switching from one program to another and satisfying users with an output from the program before switching to the next one.

What are parallel and multi-programmed batched systems? What are the differences between parallel and multi-programmed batched systems?

Multi-programmed Batched Systems:

In multi-programmed batched operating systems, the operating system reads jobs from disk drives where a list of jobs are already being stored through card readers. The operating system then pull and store as much job as it can in the memory. Then from the memory, operating system start working on a job. Now, whenever a job reaches a situation where is has to be waiting for one or more tasks to be completed like use of any IO devices, the operating system pulls another job from the memory and starts working on it. Whenever this job also starts waiting, for example it need to use the same IO which is already in use by its previous job, the operating systems pulls another job. This is how, a multi-programmed batched systems harness the power of disk drives and memory.

What are simple batch and multi-programmed batched operating systems? What are differences between simple batch and multi-programmed batched operating systems?

Simple Batch Systems:

Early computers used to take one job at a time, no input in the middle of the process and also no output either. The jobs were prepared commands for the computer to execute on its side and these jobs were generally written on cards, control cards, which the computer used to read through card readers. After processing the job, the computer used to output the data through line-printer machines or tape drives. 

So, the simple batch operating systems were designed to speed up the process by grouping jobs which are similar in nature into one job and execute them and then send back output of each jobs to its programmer. So simple batch systems lack the interaction between the programmer and the machine while it’s running or working on a job.

What are the types or categories of risks in software engineering? Explain the process of risk management.

Risk Management: Risk management is a series of steps that help a software team to understand and manage uncertainty. It’s a really good idea to identify it, assess its probability of occurrence, estimate its impact, and establish a contingency plan that─ ‘should the problem actually occur’. Risk management is a part of umbrella activities.

Simplistically, you can think of a risk as something that you’d prefer not to have happen. Risks may threaten the project, the software that is being developed or the organisation. 

Explain the generations of computer.

Very small amount storage spaceComputer systems reached today’s modern age step by step, these steps are called generations. In each generation computers with new features and functions starts to get the market and the older computers slowly gets replaced. IBM company started categorize the development of computers into generations, though not everyone in the industry including users will be agree on the periods of each generation. However, based on the use of electronic devices, computers systems can be categorized into following generations so far.

Differences between analog and digital computers.

Analog Computer: An analog computer is a form of computer that uses the continuously changeable aspects of physical phenomena such as electrical, mechanical, or hydraulic quantities to model the problem being solved. As an analog computer does not use discrete values, but rather continuous values, processes cannot be reliably repeated with exact equivalence.

Digital Computer: A digital computer is form computer that uses letters and numbers as inputs in processing and displays the result in monitors or other forms of output devices and can also store the output in memory to be used later.

Following are some key differences between digital and analog computer

What are the functions of operating system?

Functions of Operating Systems: 

Operating system’s size, organization and scope of operating vastly depends on the size, organization and use of various computer system. Obviously not all operating systems can be used on all systems. Functions of an operating system are always targeted to meet the needs. Some operating systems are designed to give more flexibility to users, some gives more priority to performance and security and some are designed to be operated by other operating systems, not humans. 

However, following are some general functions of operating systems

How software engineering is different from other types of engineering?

Software project management is an essential part of software engineering. However, good management won’t guarantee success, but bad management results in project failure. Software managers are responsible for planning and scheduling development.  They supervise the work to ensure that it is carried out to the required standards and monitor progress to check that the development is on time and within budget.

Software engineering is different from other types of engineering in a number of way which particularly makes software engineering difficult.

Explain the responsibilities or activities of software project manager?

It is impossible to write a standard job description for a software project manager. The job varies with organization and product being developed.  However, following are the responsibilities most software project managers have deal with.

What are the characteristics of computer?

Characteristics of Computer

Computer became so popular and more important part, unavoidable device of today's world because of its characteristic like correct and dependable outputs, high speed, accuracy etc. Following are the characteristics of computer:

What is computer? What are the four elements of computer? What are the functions of a computer?

Computer:

A computer is a multipurpose electronic device that can receive, store, process data and deliver information. A computer takes data such as numbers, text, images etc. as input and then process those data and convert those to useful information. Additionally, a computer can also store data and information both for future use. Also a computer can do schedules tasks.

Computers are programmed devices. Computer programmers write programs or software for computer which actually takes input, process it and outputs information.

Explain evaluation of information systems.

Evaluation of Information Systems:

The measurement of the efficiency of information systems is the evaluation of information systems. The evaluation of information systems depends on the amount of efficiency in workflow and management an organization achieved by implementing an information system. Evaluation of information systems is measured based on a few criteria as follows

Explain the types of information systems?

An organization's management generally includes one or more levels depending on the size of the organization and it's managing areas. Different types of information systems are required for different purposes of these levels. However, information systems can be categorized into two as follows,

1. Operations Support System
2. Management Support System

Discuss the role of computer in Information System.

Information systems are in use from an ancient time. With the development of computing technology, computers became an important part of today's modern information systems which satisfies speed, dependability etc. 

Following are the role of computers in Information Systems

What is information systems? What are the components or resources of information systems?

Information Systems Definition:

Systems that collect, verify, store, process, report and update data to output valuable and useful information is called an information system. Information systems are being used from ancient time period. With the development of computing technologies and it's uses, modern information systems are computer based information systems which can process billions of data to output desired information in seconds or minutes. Various types of computer based information systems are available.

What is Data and Information? Write the differences between Data and Information.

Data and Information:

Data: Raw materials used in a process to obtain targeted result of goal are called data. In other words, pieces of information which by itself may or may not mean something but useful when connected or used with other pieces of information to form a piece of information that means something, are called data.

Dynamic META Description in blogger template.

Blogger or Blogspot is a free blogging platform from Google. In blogger, you can create a blog for free and just in a few moments, you just need a google account (such as a Gmail Account) to start a blog instantly. If you are familiar with web applications like an gmail, facebook etc., that is enough to start a blog with blogger.

Anyway, though you can create a blog with just a few clicks, you might need some SEO tweaks to have your blog doing well in search engines. SEO (Search Engine Optimization) is a vast thing to discuss. In this post, we will only discuss about META keywords and descriptions in a blogger template.

META description is a small text description of what an webpage is all about. META keywords and descriptions are important parts of any website, such as your blogger blog. This two fields in your template helps the search engine bots to better understand the content of the page. Thus if you write a constant META description that appears in all of your blog pages, contents etc. then the search engine bot will not recognize each of your post well enough. For example, you might be having a post on cricket and another on football. Obviously a common description for these two posts will not help much a bot to understand the posts clearly.

What are the three principal types of critical system?

Types of Critical Systems

Those systems are called critical systems which not only causes inconvenience, no or not-noticeable impact on time, money and life but also causes loss or injuries to life, economical destruction and such bigger impacts when the system fails.

There are 3 main types of critical systems, which are as follows:

What is critical system?

Critical System

Those systems are called critical systems which not only causes inconvenience, no or not-noticeable impact on time, money and life but also causes loss or injuries to life, economical destruction and such bigger impacts when the system fails.