Learning posts

Software Crisis In earlier days, same codes needed to be written time and again increasing the complexity and time required for development This resulted in software not being completed on time and the cost increased than expected Solution: Object Oriented Programming Software Evolution Investigation Feasibility Study Analysis Design Implementation Maintenance Investigation First step in preparation of the IS includes the preliminary study of proposed information system investigates the information needs of the users and determines the resource requirement, costs, benefits and feasibility of a proposed project 2. Feasibility Study feasibility study is an analysis of the practicality of an idea focuses on helping answer the essential question of “should we proceed with the proposed project idea?” The feasibility study is conducted in four different areas: 1. Organizational feasibility 2. Economic feasibility 3. Technical feasibility 4. Operation

Object Oriented Programming Programming paradigm that represents the concept of "objects" that have data fields (attributes that describe the object) and associated procedures known as methods Programming methodology based on objects, instead of just functions and procedures Focuses on data rather than process As individual objects can be modified without affecting other aspects of the program, it is easier for programmers to structure and organize software programs Easier to update and change programs written in object-oriented languages Simula was the first object oriented programming language Eg: C++, Java, etc. Features of OOPS Objects Referred as instance of class Basic run-time entities in an object-oriented system a person, a place, a bank account, a table of data, etc can be an object They occupy space in memory that keeps its state  Each object contains data and code to manipulate the data  Classes Blue print or prototype  which defi

BIOS stands for Basic Input Output System. It is is kind of OS pre- attached in the system Design to detect every I/O devices It holds basic drivers -checks all I/O devices -Loads main OS -Responsible for starting System switched on manufactured by AMI,Phonix,award,Baiostar POST error test, boots trap load, BIOS is unintrusive system. CMOS and BIOS are two different components of the motherboard. CMOS work as storage if BIOS. A basic software program containing all BIOS is permanently stored in the ROM. every essencial holds program Tresh passing without knowinig is called intrusive.

PGA reffered as pin grid array in which pins of CPU are lined up in a straight format. SPGA referred as staggered pin grid array. in which pins of CPU are arranged staggered format. LGA reffered to as Land Grid Array in which pins are available within inside the socket but not in the CPU in other words in line grid array, in CPU ther are no pinsbut insteadpins areattached with in a socket which contact with with the CPU. for e.g. LGA775 socket(no pins on cpu) has better cooling system. better contact and better locking(climbing). LGA1155: Letest generation I socket, also reffered as sandy bridge, Turbo boost overclocking. More resent than LGA 1156 socket. LGA1156: ability to north bridge Doul channel DDR3 optional integreted graphics PCI express LGA1366: hi end core i series socket integreted tiple channal memmory controller external control bridge(HUB) Upgrading CPU: need to check its core suppert check multiprocessor supports or not check on the

 Computer is derived from the Latin word computare which mean calculate. Computer can be defined as an electronic digital and automatic machine. takes  input  from the user, process it, stores it if necessary and gives output in desired form.  Computer is the most powerful device the human being has ever invented. It brought enormous effects in our daily life and changes in the world. Features of Computer 1. High speed, decreasing size and cost 2. Accuracy and reliability 3. Vast storage capacity 4. Automatic 5. Electronic 6. Non – intelligent Advantages 1. Computer is faster then human 2. 100% accurate and reliable 3. Can perform various type of  work 4. Very useful for repeated job. 5. Complicated things are easy to show and simulate. Disadvantages 1. Danger of  electric shock and other physical Damages. 2. Failure of device and programs can produce unreliable information. 3. Increases dependency on them. 4. Simple mistake can cause loss of life and prope

   The header file graphics.h should be included to use graphics related built in functions. Again, the variable gDriver is an integer variable that specifies graphics driver to be used. Device drivers are small programs which talk directly to the hardware. Graphics drivers are a subset of device drivers and are applicable only in the graphics mode. The initialization of this variable to DETECT is to set another variable gMode to the highest resolution available for the detected driver.  The value of this variable gDriver may be another than DETECT (e.g. 1 for CGA, 9 for VGA.). The variable gMode is an integer that specifies initial graphics mode.       The built in function initgraph() is for graphics initialization. The syntax for this is as   initgraph(&graphics_driver, &graphics_mode, path_to_driver);   path_to_driver specifies the directory path where initgraph() looks for graphics drivers ( .BGI files). This function initializes the graphics system by loa

Computer graphics is one of the most powerful and interesting aspects of computers. There is a lot that we can do in graphics apart from drawing figures of various shapes. All video games, animation, multimedia predominantly works with computer graphics. To work with graphics, C has various library functions. Some of built in functions which are defined within header file graphics.h are illustrated in this chapter. Let us see one example which demonstrates graphics initialization and some built in functions related to graphics. #include<graphics.h> void main() { int gDriver=DETECT,gMode; int polyArray[]={200,100,250,150,300,200,350,200,300,150,200,100}; initgraph(&gDriver,&gMode,"c:\\tc\\bgi"); setcolor(GREEN); line(200,100,300,250); /*line from (200,100) to (300,250) */ circle(300,300,50); /*circle at center (300,300) having radius 50 */ ellipse(150,200,0,360,100,50);           /* ellipse at center (150,200) and angle from 0 to      

There are mainly three difference between binary and text mode. They are as follow.               i.       In text mode, a special character EOF whose ASCII value is 26 is inserted after the last character in the file to mark the end of file. But, there is no such special character present in the binary mode. The binary mode files keep track of the end of file from the number of characters present in the directory entry of the file.             ii.       In text mode of file, text and numbers are stored as one character per byte. For example, the number 1234 occupies two bytes in memory but it occupies 4 bytes (one byte per character) in the file. But, in binary mode, the number occupies the number of bytes as it occupies in the memory. Thus,  the above number occupies two bytes in file also in the case of binary mode.           iii.       In text mode, a new line character is converted into the carriage return-linefeed combination before being written to the disk. Likewi

     In Binary mode of data file, the opening mode of text mode file is appended by a character ‘b’ i.e. “r” is replace by “rb” “w” is replace by “wb” “a“ is replace by “ab” “r+” is replace by “r+b” “w+” is replace by “w+b” “a+” is replaced by “a+b” The default mode is text mode. Thus when simple “r” is written as mode of opening, this is assumed as text mode. We can write “rt” in place of “r” and so on in the case of text of file. The syntax for all above mode in the case of binary mode is similar to the previous one i.e. text mode like this fptr=fopen(“data.txt”,”rb”); 

               The EOF is a special character, whose ASCII value is 26, which indicates the end of a file in text mode of file. While writing data to a file, this character is inserted automatically after the last character in the file to mark the end of file. If this character is detected at any point in the file, the read function would return the EOF signal to the program indicating the last point of file. An attempt to read after EOF might either cause the program to terminate with an error or result in an infinite loop situation. Thus, the last point of file is detected using EOF while reading data from file. Without this mark, we can not detect last character at the file such that it is difficult to find up to what time the character is to be read while reading data from the file.

putpixel( ): Plot a point with specified color. Its syntax is Putpixel (int x, int y, int color), getpixel( ): gets color of specified pixel. Its syntax is integer_variable = getpixel (int x, int y); setcolor( ) : It changes current drawing/ foreground color. Its syntax is setcolor (int color); setbkcolor( ): It changes the background color. Its syntax is setbkcolor(int color); line( ): The line ( ) function can draw a line. The syntax of line( ) function is: line(x1, y1, x2, y2), where x1, y1, x2, y2 are integer type and they represent the coordinate (x1, y1) and (x2, y2). The above command draws a line joining two points with coordinates (x1, y1) and (x2, y2). lineral( ): the function lineral (x, y) draws a line joining the current cursor position and a point at a distance of x in the horizontal and y in vertical direction. Note that x and y both are integer type. lineto( ): The function lineto (x, y) draws a line joining the current cursor position

        While working with stream-oriented file, we need buffer area where information is stored temporarily in the course of transferring data between computer memory and data file. The buffer area is established as              FILE * ptr_varibale;           Where FILE is a special structure type that establishes the buffer area and ptr_variable is a pointer variable that indicates the beginning address of the buffer area. The special structure FILE is defined within header file stdio.h. A data file must be opened before it can be created or processed. This is done by following syntax          ptr_variable=fopen(file_name, file_mode); This associate file name with the buffer area and specifies how the data file will be utilized (File opening mode). The function fopen() returns a pointer to the beginning of the buffer area associated with the file. A NULL value is returned if the file can be opened due to some reason. After opening a file, we can process data files as