Hack tech fact

The file system   The DOS File system  lets us store information in named files.  You can call a file anything you like which might help you remember what it contains as long as you follow certain basic rules. 1.   The names can be up to 8 characters long. You can use letters and digits but only a few punctuation marks (! $ % # ~ @ - () _ {}). You can't exceed 8 characters or use spaces or characters like * or ? or +. Names are case-insensitive, i.e. it doesn't matter whether you use capitals or lowercase letters; “A” and “a” are treated as the same thing.  2. File name can also have an extension  of up to three characters, which describes the type of file. Three are some standard extensions, but you don't have to use them. Examples include COM and EXE for executable programs, TXT for files, BAK for backup copies of the files, or CPP for C++ program files. The extension is separated by a dot from the rest of the filename.  For example, a file call...

Introduction to DOS ➡️ DOS stands for (Disk operating system), and it is a name for the basic IBM PC operating system. DOS is command User/Line interface (CUI) Operating system software. Several varieties of DOS are available , including Microsoft's versions of DOS (MS-DOS) , IBM's version (PC-DOS) , and several others.             There are actually several levels to DOS. At  the lowest level is the BIOS  (Basic input/output system)  which is responsible for managing devices like the keyboard and disk drivers at simplest possible lavel e.g. the BIOS let's you say things like ( get me sector 5 of track 3 from disk drive 1). This is done partly by software in ROM (Read-only memory) and partly by BIOS extension, which are loaded when the system first starts up (with MS-DOS, these are in a file called IO.SYS; on PC-DOS they're in IBMBIO.COM).     The second layer provides a set of higher level services implemented using the low-level B...

Start menu                            Commands:>  > My Documents Used to open my Documents folder, where you can access /store /manipulate your letters, reports, documents and other documents.  > My music Open music folder, where you can store music files and other audio files. > My pictures Open my picture folder, where you can store digital photos, images and graphic files.  > My computer  Gives access and information about all the storage Disks, SSD, Hardware and other devices connected to your system.  > Control panel Provide options to customize the appearance and functionality of your system add or remove programs, setup network connection, setup user account, setup printer and other hardware. > Set program Access and Defaults Used to allow the user to interact with the default programs and applications like web Browsing and desktop application. > Connect to Used ...

Packages It is an application program that is designed to handle a particular task. It can be either a routine package or designed for a specific purpose. All input/output transfers and error situation are aromatically handled by the package itself.   Example of packages DTP :  It stands for Desk Top publishing, which allows many organization's to produce camara ready artwork in hour, thereby saving considerable expenses on outside expertise. There are some special types of word processing packages, which can fulfill the requirements of publishing industry and hence these came to know as Desk top publishing packages. The most common DTP in use in india are Page maker and ventura for English language and for indian language shreelipi, indica etc. DBMS : It is the Database Management system that allows the user to setup, maintain and manipulate a database management task may include controlling excel to the database, extracting data selectively from different parts of database, ...

Classification of     digital computer -> Digital computer has been classified into two types: 1- Purposes-wise  2- Size-wise  Purposes-wise   1- special purpose : used to perform specific task. The program or institutions set in permanently stored in such a machine, which perform a single task quickly and effectively can be used for separate purposes like weather forecasting etc. 2- Genaral purpose : used for different purposes. Numerous appreciation are loaded to different purposes that can be used for office Automation, Research, Entertainment, Commercially purposes, Education etc.  Size-wise 1- micro Computer : Lot of changes has taken place in microprocessor architecture in these days. The introduction of multimedia, 3D animation, editing, gaming etc,  technology into a a processor for entertainment media is very popular now days. The present range of CPU included -.  Intel xeon E5205, Intel i7-975 Extreme Edition Bloomfleld, AMD...

Units of computer-> A computer system is made up mainly three Units.  1- Input unit 2- system unit or processing unit 3- Output unit Input unit ->   This unit, which is used in transferring the data or instructions to the computer system, is called as the input unit. Also the input unit is a collection of input devices. Examples of input devices available in input unit are keyboard, mouse and microphone etc. System unit or processing unit->    A system unit mainly consists of the followings:  1- Central processing unit (CPU) or microprocessor.  2- memory unit with primary memory and secondary memory drives.  3- SMPS (Switch mode power supply)  4- Motherboard or pcb (Printed circuit Board).  5- Drive controller card. 6- Math Co- processor. 7- Ports. 8- Adaptor.   Central processing unit (CPU) -> The central processing unit is regarded as the brain of the computer. The CPU provides the fundamental command and instruction enviro...

Features of                                computers- Computer has become the life style of mankind because of the following characteristics:  a >  Speed: The processing speed of a computer is very fast/very high. It can perform any type of calculation within a fraction of seconds. The speed of the computer can be measured in pico seconds i.e. Billionth (10-¹²) part of a second. b> Accuracy: The output of result given by the computer is very accurate. A calculator can give maximum 9 to 10 digitise results wheather decimal digit may cross the range where as a computer can give the accurate decimal values. A computer never gives any wrong information unless and until the user does because computer does all the operation using electronic circuits. c> Storage: One of the most important characteristics is that a computer can store large amount of data and whenever it is required to retrieve it ...

Are the molecularity and reaction order different for elementary reactions?    It may be stated once again that the total number of molecules or atoms which participate in a reaction as represented by the chemical equations is known as the molecularity of the reaction. The sum of the power to which the concentrations are raised in the rate law is termed as the order of a reaction. Let us consider an elementary reaction of the type.        2A + B --> Products.          Since the rate of a reactio n is proportional to number of collisions between the atoms or molecules of the reactants, and the number of collisions is proportional to the concentration of each reactant species, the rate of the above reaction                alfa [A²] [B²].          rate = k [A²] [B]  Molecularity of reaction =       2 + 1 = 3    It shows that the moleculari...

Molecularity of a reaction:   It may be defined as the number of reacting species (atoms, ions or molecules) that collide simultaneously to form the product in the rate determining step of a chemical reaction.       Now, we have two types of chemical reaction, namely: (1) Elementary reactions, android (2) Complex reactions.

Difference between rate of reaction and rate constant:   1- Rate of reaction (r) = Rate constant (k)×(conc), when concentration is one molar, r = k. 2- Rate of reaction depends on the concentrations of reactants and the temperature whereas the rate constant does not depend on the temperature. 3- The rate of reaction at a particular instant is the instantaneous rate of change of concentration of any one of reactant or product at that instant. On the other hand the rate constant is a constant of proportionality, and it equals the rate of reaction when the molar concentration of the reactants is unity.