Full In-Depth IEB Computer Applications Technology (CAT) Hardware Notes for Grade 11 and Grade 12. It gives an outline on all Hardware listed in the IEB SAGS (Subject Assesment Guidelines) Document and therefore is perfect for any school on the IEB syllabus
Hardware
Hardware refers to the physical components of a computer that you can touch.
The Information Processing Cycle
Input Output
The computer receives instruction – what to The computer gives feedback on the results
do and what to work on. This input is given of its processing such as images or text on
by the keyboard and mouse. screen.
Processing
The computer works on the data –
e.g., calculating, searching, etc. This
is done by the CPU.
Communications
Storage Input
Computers linked to other
Keeps a permanent record of data.
computers can communicate.
Communication can provide input
or output for the computer.
Modular Design
Modular Design – The computer is put together in parts, rather than coming in a single unit where hardware is
fixed.
Advantages of Modular Design:
✓ Repairs: If part of the computer is damaged, only the part damaged can be sent for repairs rather than
the whole computer. This minimises disruptions.
✓ Upgrade: It makes it simpler to upgrade the computer with between hardware.
✓ Flexibility: It allows for a variety of components to be added based on the user’s needs.
1
, System Units
Motherboard
This is a large circuit board that all the other components (such as RAM) plug
into. It provides a way for all components to communicate with each other.
CPU (Central Processing Unit)
This does all the processing. The speed in measured in GHz.
Multiprocessing –When the ‘dual core’ or ‘quad core’ (or any other ‘core’) is used
to describe a CPU, it tells you how many physical CPUs are on the chip. A ‘dual core’
has two physical CPUs and can split work between processors, allowing the
computer to work more efficiently.
Processor Cache – The speed of the CPU is faster than RAM. Cache memory is a
similar speed to the CPU. It stores blocks of data that has been pre-fetched from slower RAM in the hope these
instructions will be needed again by the CPU.
RAM (Random Access Memory)
RAM holds all the programs and the data it is currently working on. Memory is
volatile – it only keeps its contents when supplied with power. It is sometimes
referred to as “primary storage”.
RAM comes in modules called DIMMs (Dual Inline Memory Modules) that plug into
the memory slot on the motherboard. The higher the frequency of RAM, the faster
data can be transferred to and from the RAM. Memory is measured in low Gigabytes range (1- 64 GB).
The most used type of RAM is DDR SDRAM (Double Data Rate Synchronous Dynamic RAM). More RAM reduces
the amount of virtual memory needed as more programs and data can be stored in RAM at one time.
A comparison between the common different types of RAM:
Type Definition Data Retention Speed Cost Use Cases
SRAM Static Random- Retains data as Fast More CPU caches, embedded
Access Memory long as power is expensive systems
on
DRAM Dynamic Random- Requires periodic Slower than Less Main memory (RAM) in
Access Memory refresh SRAM expensive computers
SDRAM Synchronous Requires periodic Faster than Less Main memory in PCs
Dynamic Random- refresh DRAM expensive and servers
Access Memory
DDR Double Data Rate Requires periodic Faster than Less High-performance RAM
SDRAM Synchronous refresh SDRAM expensive in modern PCs, laptops,
DRAM and servers
2
, ROM (Read Only Memory)
This is one or more chips on the motherboard that holds the programs that control
the basic hardware of the computer and that are used to get the computer ready for
use when you switch it on.
Types of Non-Volatile Memory:
• PROM (Programmable Read-Only Memory): One-time programmable, permanent data storage.
• EPROM (Erasable Programmable Read-Only Memory): EPROM can be programmed and erased
multiple times. Reprogrammable after UV light erasure, used for firmware that may need updating.
• EEPROM (Electrically Erasable Programmable Read-Only Memory): Electrically erasable and
reprogrammable, suitable for applications requiring frequent updates and easy reprogramming.
BIOS (Basic Input/Output System)
A BIOS (Basic Input/Output System) is stored on a small chip on the motherboard and is responsible for
starting up your computer by performing hardware checks and initialising system settings before passing
control to the operating system.
A BIOS chip is a small chip on the computer's motherboard that stores the BIOS firmware.
Firmware is a specialised type of software that is embedded into hardware devices to control and manage
them.
How the computer starts itself up
1. When the computer is switched on, the BIOS in ROM sends instructions to the CPU to start the boot
process.
2. The BIOS performs a Power-On Self-Test (POST) to check hardware components for errors. If an
error occurs, the computer usually won’t start and will indicate the problem through beeping or
error messages.
3. After the checks, the BIOS looks for the boot program on the computer’s storage device, loads the
operating system into RAM, and the computer is now ready for use.
Graphics Card
A graphics card contains a specialised processor called the GPU (Graphics Processing
Unit). It connects to the motherboard via a slot such a the PCIe. The GPU processes
images stored Video RAM (VRAM). It offloads the burden of image processing on the
CPU, allowing the CPU to perform other tasks.
GDDR5 is the most used VRAM. GDDR5X is a higher-end graphics card and is twice
and GDDR5.
Frames Per Second (FPS): It measures how many frames the GPU (graphics processing unit) renders per
second. Higher FPS means smoother motion in gaming or video playback.
Integrated Graphics –Instead of a separate GPU, the GPU is embedded into the CPU and instead of a separate
VRAM, the GPU shares system RAM. It is sufficient for the average user.
3
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through EFT, credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying this summary from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller shivaanharipersad. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy this summary for R150,00. You're not tied to anything after your purchase.
