Advantages of direct memory access (DMA) in OS

Direct memory access (DMA) is a technology that is used by computers to increase speed and efficiency by allowing input-output devices to access RAM directly without involving the CPU. Before the use of DMA, computers used to fully involve the processor in the whole process of sending and receiving data from input and output devices. It started with programmed input/output and then interrupt and then later DMA.

When using programmed input/output, the processor sends the request to the input/output module to transfer data and then keeps checking if the transfer is done. This keeps the CPU busy checking whether the transfer is done. This reduces the overall performance of the computer.


Network switch types, functions advantages, and disadvantages 

A network switch is a networking component device that is mainly used as a central point to connect multiple devices within a network. A network switch is intelligent in such a way that it is possible to identify the destination address of the message and direct it to that device instead of broadcasting. They operate at the data link layer (layer 2) on the Open System Interconnections (OSI) model.

The main types of network switches are managed, smart, PoE, and unmanaged. They are used to forward packets within the same network and they use MAC addresses to identify the source and destination of packets. Switches help manage devices on a network. However, they are expensive and for the advanced managed device they require an expert to configure.


Features, types, and advantages of mobile operating system

The mobile operating system is software used to manage users, hardware, and other software of a mobile device. It is designed to work on a device with limited capabilities, unlike the desktop operating system. They are lightweight compared to desktop OS.

Other than the smartphone these operating systems are also used in tablets, smartwatches, and other smart devices that are emerging.

The main features of smartphone OS are telephone communication, wireless network, GPS support, online App store among others. Some examples of types of mobile operating systems are Android, Apple iOS, Windows, Symbian, Banda, Blackberry, etc. Othe his article we discuss these types, features, advantages, and disadvantages of mobile OS.


Hybrid topology advantages, disadvantages, and features

A hybrid topology is a type of computer network layout that uses more than one topology such as a bus-star combination. The hybrid is sometimes also known as tree topology where the linear bus topology is used as the trunk of the tree and the star topology becomes the tree branches.

The hybrid combines the advantages of the 2 topologies and tries to reduce the disadvantages of each. Its other main benefits are reliability and scalability. However, it is complex and expensive to implement. A hybrid network topology can either be a star-bus, star-ring, or hierarchical layout.


Advantages and disadvantages of optical character recognition

Optical character recognition also known as text recognition is a technology that is used to convert images and other scanned documents into computer-editable text. The OCR technology uses software and an optical character reader to convert images, handwritten, and scanned documents into machine text readable documents.

An optical character reader is categorized as an input device of the computer since it allows scanning and inputting the images to the computer as text.

OCR’s main benefit is to automate and increase efficiency in the data entry process. It also reduces the cost of data entry. However, the technology is expensive to implement when using advanced software. It also has limited languages that it can recognize and it doesn’t necessarily maintain the original document formats.


Star topology characteristics, advantages, and disadvantages

A star network topology is a type of network layout where all the devices are connected to a central point. The central device can be a network switch or a hub. The layout of the network has the hub or switch at the center of the network and then all other network components are connected to it.

The main feature of star topology is it has a central device that controls all other devices on the network. The direct cable link to the central device means the data transfer is fast and troubleshooting where the problem is simple. However, it requires an expensive hub and connection cables.


Magnetic ink character recognition uses and advantages

Magnetic Ink Character Recognition (MICR) is a technology that is used to read characters printed using special magnetic material. They are categorized under input computer devices. MICR is used mostly in banks to verify the authenticity of bank cheques and other financial documents. 

The characters on these documents are printed using special ink that contains iron oxide particles. The magnetic ink character reader is then used to read the character by sensing the magnetic material.


Difference between CD, DVD, and Blu-ray discs

CD, DVD, and Blu-ray are types of optical discs that are used for the permanent storage of data. They are used to store music, video, images, and other variety of data.

The main difference between the 3 types of optical discs is the storage capacity and the types of data that each disc can store. Again while the CD and DVD use red laser light to read and write data Blu-ray uses a blue laser.


Mesh topology advantages, disadvantages, and features

A mesh network topology is a network layout where each device is connected. The connection can be wired or wireless. Each node on the network is capable of communicating with the other and they also act as a relay to pass messages to their destination. The most practical and common type of mesh is wireless since it doesn’t require a physical connection and it is cheaper.

A mesh network topology is characterized by having a direct link for each device and having a high redundancy. The 2 types of mesh topologies are full and partial. The main advantages of using mesh are it offers high fault tolerance and has different paths for the message to reach its destination. However, it is expensive to implement and requires more cables than other types of topologies. 

Command line interface (CLI)

Features, advantages, and disadvantages Command line interface (CLI) 

A command line interface is an interface where the user uses text-based commands to communicate with the system. It is also known as a character or console user interface. It was the main way for a user to interact with the computer operating system and application before the use of GUI.

Today it is still embedded in all GUI systems and it is mostly used by advanced users or those who are willing to learn the commands. It is mostly used by software programmers, systems, databases, and network administrators, among other IT specialists.

The main features of CLI are text-based commands, scripting capabilities, and pipes among others that are discussed in this article. The main benefits of using CLI are that it executes its commands faster and requires fewer resources. However, it is not user-friendly and it is hard to learn all the commands.