Computer systems 5.1 & 5.2

Notes for 5.1 and 5.2

In the memory hierarchy, what are the three main factors traded off against each other?

Speed, Capacity, and Cost.

What is the defining characteristic of Volatile memory?

Data is lost when the power supply is turned off. (Applies to RAM and Cache).

What type of memory is used to store the BIOS or firmware needed to boot the computer?

Read Only Memory (ROM).

Where is Cache Memory physically located and what is its main function?

Located between the CPU and Main Memory (RAM); its function is to store frequently used data/instructions for faster access.

What is the primary function of Registers?

To temporarily hold data, instructions, or addresses inside the CPU for immediate use.

Why is Secondary Storage required in a computer system?

t provides non-volatile storage for large amounts of data and programs permanently.

How does a Magnetic Disk (HDD) fundamentally store data?

Using magnetic spots on spinning platters, where the presence or absence of a spot represents a binary 1 or 0

Name two advantages of Solid State Drives (SSDs) over Hard Disk Drives (HDDs).

They have no moving parts and are generally much faster.

What is the hardware component that acts as the interface between a peripheral device and the System Bus?

The Device Controller.

What is the software that enables the OS to interact with the device controller?

The Device Driver.

What is the limitation of using Interrupts for I/O handling, especially with large data blocks?

t is inefficient because the CPU is involved in managing every data transfer.

What is the key advantage of Direct Memory Access (DMA) over interrupt-driven I/O?

DMA allows the device controller to transfer data directly to/from RAM without CPU involvement, freeing the CPU for other tasks.

What must the device controller request before it can perform a DMA transfer?

Temporary control of the System Bus

What is the difference between soft copy and hard copy output?

Soft copy is temporary (e.g., monitor), while hard copy is physical and permanent (e.g., printer).

Name two examples of I/O devices that combine both input and output functions.

Touch Screens, Fax Machines, or Multi-functional Devices.

What key feature of a monitor is measured in pixels?

Resolution.