MEMORY ORGANISATION TOPIC 5

Question 1

Types of Computer Memory

Answer 1

1. Computer Memory
2. Primary Memory (RAM, ROM)
3. Secondary Memory (HDD, SDD)

Question 2

What is computer memory?

Answer 2

• Its the most important part of the computer system.
• Memory is combination of memory cells with each cells length is 8 bit (1byte)

Question 3

Primary memory

Answer 3

1. RAM (SRAM)
2. ROM (PROM)
3. Hybrid (Flash memory)

Question 4

Memory hierarchy - Registers

Answer 4

• Register is a small permanent storage location within a CPU.
• The data not stores permanently.

Question 5

Memory hierarchy - Cache Memory

Answer 5

• One of the fastest memory is called cache memory
• Resides between CPU and main memory and stores all frequently used data.

Question 6

Memory Hierarchy

Answer 6

1. Internal memory or primary memory (Cache memory and registers).
2. External memory or secondary memory (Magnetic tape, disc)

Question 7

Memory hierarchy - Main memory

Answer 7

• Main memory is critical component of all computing systems: server, mobile, embedded and desktop

Question 8

MEMORY HIERARCHY:

Answer 8

1. REGISTER (CPU)
2. CACHE MEMORY (CACHE)
3. MAIN MEMORY (RAM,DRAM)
4. LOCAL SECONDARY STORAGE (HARD DISK)
5. OTHER / REMOTE SECONDARY STORAGE (OPTICAL DISC)

Question 9

RAM (random access memory)

Answer 9

The RAM family includes two important memory devices:
1. static RAM (SRAM)
2. dynamic RAM (DRAM)
SRAM retains its contents as long as electrical power is applied.
DRAM has an extremely short data lifetime about 4 milliseconds. Is used to refresh data before it expires.
- Computer’s short term memory

Question 10

ROM (read only memory)

Answer 10

• ROM is a class storage medium used in computers and other electronic devices.
• Data stored in ROM cannot be modified
• Helps starts up the computer

Question 11

Types of ROM:

Answer 11

PROM (programmable read only memory)
- empty od data when manufactured
EPROM (Erasable programmable read only memory)
- Can be programmed, erased and reprogrammed.
- After reprogramming the window is covered to prevent new contents being erased
EEPROM (Electrically erasable programmable read only memory)
Flash ROM

Question 12

Secondary Storage

Answer 12

1. CPU registers
2. Cache
3. Primary memory
4. Disk storage (secondary memory)
5. Tape (tertiary memory)
   They are large, cheap, and non volatile

Question 13

Computer storage devices characteristics:

Answer 13

1. Volatility
2. Differentiation
3. Accessibility

Question 14

Types of computer storage devices

Answer 14

1. Magnetic storage devices
2. Optical storage devices
3. Flash memory devices
4. Online cloud storage devices

Question 15

Memory Capacity

Answer 15

• bit = smallest unit of computer memory​
• nibble = 4 bits​
• byte = 8 bits​
• kilobyte = 1024 byte = 1 kb​
• megabyte = 1024 kb = 1 mb​
• gigabyte = 1024 mb = 1 gb​
• terabyte = 1024 gb = 1 tb​
• petabyte = 1024 tb = 1pb