SCAS - BCA ANSWER SCHEMES

 Answer any 10 questions. Each question carries 2 marks. (Write in not less than a paragraph) 1. What is the significance of Addressing mode? Explain any one addressing mode. Significance of Addressing mode  To give programmers to facilities such as Pointers, counters for loop controls, indexing of data and program relocation.  To reduce the number bits in the addressing field of the Instruction. Addressing Mode 1.Implied Mode 2.Immediate Mode 3.Register Mode (Explain any one with example) 2. What is the use of IR register. The instruction registers (IR) is used to hold the instruction that is currently being executed.  3.Write about fetch-decode-execute cycle. 1. Fetch stage: The next instruction is fetched from the memory address that is currently stored in the program counter and stored into the instruction register. At the end of the fetch operation, the PC points to the next instruction that will be read at the next cycle. 2. Decode stage: During this stage, the encoded...

 1. Picture definition is stored in a memory area called the refresh buffer or frame buffer. This memory area holds the set of intensity values for all the screen points. Stored intensity values are then retrieved from the refresh buffer and "painted" on the screen one row (scan line) at a time . Each screen point is referred to as a pixel . 2. Typefaces (or fonts) can be divided into two broad groups: Serif type and sans serif. Serif type has small lines or accents at the ends of the main character strokes, while sans-serif type does not have accents. 3. Another kind of constraint is a grid of rectangular lines displayed in some part of the screen area. When a grid is used, any input coordinate position is rounded to the nearest intersection of two grid lines. 4. Clipping determines each element into the visible and invisible portion. Visible portion is selected. An invisible portion is discarded. Types of Clipping: 1. Point Clipping 2. Line Clipping 3. Area Clip...