Looking for comprehensive PGDCA (Post Graduate Diploma in Computer Applications) notes on Computer Memory for the 2026–27 academic session? Access complete theory explanations, memory hierarchy diagrams, short notes, long analytical answers, objective MCQs, and exam-oriented solutions covering Volatile vs. Non-Volatile Memory, Main Memory (SRAM, DRAM, ROM types: PROM, EPROM, EEPROM), Cache Memory mapping, Virtual Memory, CPU Registers, and memory organization principles tailored for university diploma exams.
Computer Memory
Computer memory is organized hierarchically based on access speed, physical cost, and total storage capacity.
Definition for Exam:
Computer Memory refers to the physical hardware components used to store data, instructions, and intermediate results temporarily or permanently.
+——————-+
| REGISTERS | (Fastest, Smallest Capacity)
+———+———+
|
+———v———+
| CACHE MEMORY |
+———+———+
|
+———v———+
| PRIMARY MEMORY | (RAM / ROM)
+———+———+
|
+———v———+
| SECONDARY STORAGE | (Slowest, Largest Capacity)
+——————-+
Primary Memory: RAM vs. ROM
| Parameter | RAM (Random Access Memory) | ROM (Read Only Memory) |
| Volatility | Volatile (data lost when power turns off). | Non-Volatile (data retained permanently). |
| Operation | Read and Write capabilities. | Read-Only capabilities (under standard operation). |
| Purpose | Holds active programs and working data currently in use. | Stores startup instructions (BIOS/Bootloader). |
| Types | SRAM (Static RAM), DRAM (Dynamic RAM). | PROM, EPROM, EEPROM. |
PGDCA Computer Memory Notes
Q1. Define Cache Memory and state its purpose. [2 Marks]
Answer: Cache Memory is an extremely fast, small, high-cost volatile semiconductor memory placed between the CPU and main RAM. Its purpose is to store frequently accessed data and instructions to reduce CPU wait time.
PGDCA Memory Hierarchy Important Questions 2026-27
Q2. What makes RAM volatile? [2 Marks]
Answer: RAM (Random Access Memory) is termed volatile because it requires continuous electrical power to retain data. As soon as the computer power supply is turned off, all data stored in RAM is immediately lost.
PGDCA Cache and Virtual Memory Solutions
Q3. Differentiate between SRAM and DRAM. [3 Marks]
Answer:
| Parameter | SRAM (Static RAM) | DRAM (Dynamic RAM) |
| Technology | Built using flip-flops (transistors). | Built using capacitors and transistors. |
| Refreshing | Does not require periodic refreshing. | Must be refreshed thousands of times per second. |
| Speed & Usage | Extremely fast and expensive; used for Cache. | Slower and cheaper; used for Main System RAM. |
Q4. What is the BIOS and where is it stored? [2 Marks]
Answer: The BIOS (Basic Input/Output System) is essential firmware containing computer startup and hardware initialization routines. It is stored permanently in non-volatile ROM (Read-Only Memory) on the motherboard.
Computer Memory PGDCA Syllabus Question Answer
Q5. Explain the difference between PROM, EPROM, and EEPROM. [3 Marks]
Answer:
- PROM (Programmable ROM): Written once by the user using a special programmer; cannot be modified or erased afterwards.
- EPROM (Erasable PROM): Can be erased by exposing the chip to strong Ultraviolet (UV) light for several minutes, then rewritten.
- EEPROM (Electrically EPROM): Can be erased and reprogrammed electrically block-by-block without removal from the circuit board (e.g., Flash memory).
🧠 PGDCA Exam Preparation Notice: This page provides curated PGDCA (Post Graduate Diploma in Computer Applications) Computer Memory Study Material & Solutions updated for the 2026–27 academic session. This complete guide features memory hierarchy pyramid diagrams, SRAM vs DRAM comparative charts, Cache memory levels (L1, L2, L3), virtual memory paging workflows, and high-yield exam questions designed to help you secure top marks in your semester examinations.
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