The document discusses core hardware components of a personal computer including DRAM, the motherboard, BIOS, and the power supply. It explains that DRAM is the main memory of a PC using transistors and capacitors to store data. The motherboard connects all the parts together with sockets for the CPU, RAM, and expansion cards. BIOS is the basic input/output system stored in ROM that performs startup procedures like detecting devices and loading the operating system. The power supply converts alternating current to direct current for the computer components.

1. Lecture 3
Core hardware and PC Maintenance

2. Outline
• DRAM
• Motherboard
• BIOS
• Power Supply

3. DRAM
• Dynamic random access
memory (DRAM) is a type of
semiconductor memory.
• DRAM is widely used as a computer's
main memory.
• Each DRAM memory cell is made up of
a transistor and a capacitor within an
integrated circuit.
• Random access allows the PC
processor to access any part of the
memory directly rather than having to
proceed sequentially from a starting
place.

4. Motherboard
• A motherboard is the main circuit
board inside a computer that
connects the different parts of a
computer together. It has sockets
for the CPU, RAM and expansion
cards and it also hooks up to hard
drives, disc drives and front panel
ports with cables and wires.

5. BIOS
• BIOS, in full Basic Input/Output
System, computer program that is
typically stored in EPROM and used
by the CPU to perform start-up
procedures when the computer is
turned on. Its two major procedures
are determining what peripheral
devices (keyboard, mouse, disk
drives, printers, video cards, etc.) are
available and loading the operating
system (OS) into main memory.
• If your computer boots up in 5-15
seconds, it's just fine.

6. Power Supply
• A power supply is an electronic
circuit that converts the voltage
of an alternating current (AC)
into a direct current (DC)
voltage. It is basically consisting
of the following
elements: transformer, rectifier,
filter and regulator circuits.