(N22) PC Hardware Basics part2 RAM and ROM, RAM,ROM, BIOS , BIOS Settings
20230403 115216
RAM and ROM
Primary Memory – RAM and ROM
RAM ROM
Random Access Memory Read Only Memory
Temporary Permanent
Volatile memory Non volatile memory –NV
When power off – data lost Data available even power is off
Ex. hdd, SSD, PENDRIVE, SD CARD
Can changeable add/remove/replace – fixed CHIP on MB
RAM (Random Access Memory) – Main memory
Primary Storage for the CPU
Integrated Circuits are used to Temporarily Store Programs, Instructions and Data.
It is a Volatile Memory (Requires Power to Store the Data).
RAM
Static RAM Dynamic RAM
SRAM DRAM ECC EDO VRAM
-CACHE MEMORY SDRAM
--build inside of cpu DDR-SDRAM
DDR2
DDR3
DDR4
DDR5 – Intel 12th gen i3,i5,i7
RAM Specifics
Size : MG, GB, TB , ex. 4GB, 8GB, 16GB
Speed – MHz ex. 1333MHz, 1600MHz,
Model: DDR3, DDR4.,
Voltage Level
To upgrade/ replace RAM
Check CPU Model Specification – Support – Size, Speed, Memory Types
Check Motherboard Specification – No of RAM Slots, Memory Type
Voltage levels – L /H– 1.5v, 3v
Matches to old RAM
Frequency Matches
Type of Package
DIP
SIMM - Single In-line Memory Module
DIMM - Dual In-line Memory Module – Desktop
RIMM – Rambus In-Line Memory Module
SO-DIMM – Small Outline DIMM (Laptop, Mini PC)
Types of Dynamic RAM
SD-RAM (Synchronous Dynamic) 168 Pins
DDR-RAM (Double Data Rate) 184 Pins
DDR2-RAM (Double Data Rate) 240 Pins
DDR3-RAM (Double Data Rate) 240 Pins
Start PC - Press Power button - system perform POST (Power On Self Test) operation to make sure all primary device(CPU, RAM, MB .,)
POST Success - next step of Boot Processing
POST Failure – troubleshoot
If POST Failure – Nothing on Monitor(Blank Screen) , Continues Beep Sound,
No KeyBoard LED Blink.,
Mostly RAM loose connection, RAM Failure, Dust on RAM & RAM Slots
Disconnect Power Card connection, open Cabinet, Remove RAM, clean RAM Edged with Eraser, Clean Dust on RAM & RAM Slots
Connect RAM and start PC, verify Cross verify with other PC’s
ROM (Read Only Memory)
Integrated Circuits that are Used to Permanently Store Start-Up (Boot) Instructions and Other Critical Information
Types of ROM
PROM (Programmable Read Only Memory)
EPROM (Erasable Programmable Read Only Memory)
EEPROM (Electrically Erasable Programmable Read Only Memory)
EEPROM – Rewritable
ROM chip fixed, ROM has a program called BIOS (firmware)
BIOS (Basic Input Output System)
During the Boot up it Performs POST (Power On Self Test)
Recognizes the Hardware Devices
Locates and Loads the Operating System
It Helps the Operating System to Access the Hardware Devices
BIOS – Firmware
UEFI -Unified Extensible Firmware Interface
(New version of BIOS)
AMIBIOS
AWARD
PHOENIX
Firmware is software that provides basic machine instructions that allow the hardware to function and communicate with other software running on a device. Firmware provides low-level control for a device's hardware.
BIOS contains Hardware Information, we can check or change some Hardware setting through BIOS Setting
How to go BIOS setting :
Press Power Button press BIOS Key to goto BIOS Setup
BIOS Keys – DEL , F2, F10,F12,F11,F9
Fn + BIOS key
Ex. Fn + F2
Date and Time
Set Password*
Enable/Disable Hardware feature – Virtualization technology
Change Boot Priority
Save and Exit – F10
bios password is different from OS password
Check System Configuration – CPU, RAM, HDD/SSD…
CMOS Battery
Battery which Powers BIOS Memory is called as CMOS Battery
CMOS Battery made by Li , 3V
If you remove the battery BIOS setting goes to Factory defaults
BIOS stores a temporary data
Date and Time
BIOS Passwords
BIOS settings / Configuration
When System Turn off data lost, to keep data we use CMOS battery
CMOS:
A complementary metal-oxide semiconductor (CMOS) is the semiconductor technology used in most of today's integrated circuits (ICs), also known as chips or microchips. CMOS transistors are based on metal-oxide semiconductor field-effect transistor (MOSFET) technology.
CMOS Checksum Error
When system is Power ON on the screen
It showing CMOS Checksum Error
BIOS firmware issue.
CMOS Battery(Li 3v) - low/no power
CMOS Battery removed and reinserted
Every time system starts if you got this
Error - means Battery low/no power
So then change Battery
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