Port

Parallel Port:

1. Type A – DV25 Port. 25 pin
2. Type B – Centronics Connector . 36 pin.
3. Type C – Mini connector. 36 pin


Communication Method
Communication Method are of two types:

1. Serial Communication ------ 1-0-1-1-1-1-1-1
2. Parallel Communication ----- 1-1
0-0
1-1
1-1

Serial Communication are of two types:

1. Synchronous – Total data at a time as a Frame. Router use this method.
2. Asynchronous – Single character at a time, by different channel & different signal. 1 channel - 1 bit. Modem device use this method.

Computer’s support Parallel Communication. Data receive by computer parallely, but after receive by port it become Serial.

What is Hand Shaking?
When two modem establish communication with each other then its called hand-Shaking.

How Modem Work?
Modem works on bps.

What is Modulation And Demodulation?

What is Frequency?
Frequency means Wave. Like device man has frequency also. As - Frequency of brain which called Telepathy.

Wireless Connection:
Wireless Connection can be of 3 types:
1. Infrared: Infrared works by Ray.
2. Radio Frequency: It has no limitation, it can connect device to device device to man.
Blue tooth : Same as like Radio Frequency but by default it is limited. It can connect device to device

What is ROM?

Rom is non-volatile Memory. Its about 4 kinds:

1. ROM (Read-only Memory) - It’s a chip which can’t be altered. Technically, its called Masked ROM Chip.
2. PROM (Progammable Read-only Memory) - It’s a blank Rom chip, which is burned on a special kind of Rom Burner. In this chip the instruction remain burn, Later which can’t be changed, update and add.
3. EPROM (Erasable Programmable Read-only Memory) – Its like as PROM, but a square crystal reside on its top, by which data can be erased. UV Light is used to change the binary data of EPROM to its original state.After erasing the data, by using Rom Writer, data can be write again on EPROM
4.EEPROM (Electrically Erasable Programmable Read only Memory) – Its called flash ROM also. It’s a chip which can be reprogram by BIOS/Chip Manufacturer, they ues software to do this. This process is called Flashing.
To reprogramm EEPROM we don’t need to remove this from the system. Like – PenDrive & BIOS which can electrically read, write and delete data.

Difference between the EEPROM of Pendrive & Bios
Pendrive & BIOS both can electrically read, write and delete data, but pen drive’s EEPROM is not CIMOS, BIOS’s EEPROM is CIMOS.


What is Propritery?
Many notebook use Proprietery formats for their Memory Modules. Then to upgrade or replace RAM, we need to upgrade or replace the RAM from the company who has the propritery of the RAM.

Monitor

Monitor

Monitor’s are of two types:
1. CRT (Cathode Ray Tube) Monitor
2. LCD (Liquid Crystal Display) Monitor

1. CRT: Connectors – DV15. In Bangladesh this type of connectors are common for Monitor.

2. LCD: Connectors are of Two type:
a. CRT: Pin – 15
b. DVI : DVI are of two types:
a. DVI – I : More then 8 pin
b. DVI – D: Less then 8 pin.

Measure the Performance of AGP:
By Display characteristics we can measure the performance of AGP:

1. Dot Pitch: Every picture is a collection of Dot. The distance of these Dot is called Dot Pitch. When the dot pitch become less, the Picture become more Sharp.

2. Resolution: By counting the dot of row and column we can measure the resolution. Resolution = row * column ## (640*480) - this resolution is common.

3. Refresh Rate: By which speed the picture or the dot of picture come to the monitor is called Refresh Rate. If refresh rate speed is less then 60 hertz the picture on the monitor will be moving.

4. Color Depth: The main color of computer is RGB.

5. Font: The style of writing.

6. Display Settings:
i. Brightness
ii. Contrast
iii. Destortions
iv. Diguss

Classifications of RAM

Classifications of RAM

RAM: It can access any memory Randomly, so its called RAM.

Memory can be divided into two topics:
1. Physical Memory – Physical memory consists of hardware components.
2. Logical Memory – Logical Memory relates to how memory is looked at and accessed by the CPU.

Physical Memory Module / Packaging:
1. DIPP - Easily distinguished from SIMMs or DIMMs. DIPP are usually mounted directly to system board via a series of prongs along each side of the microchip. This type of memory is no longer used to provide main system memory.
2. SIMM – Single-in-Line Memory module . SIMM are available in 30 pin & 72 pin forms. 30 pin SIMM’s are 8 – bit meaning it can transferred into or out of the module 8 bits at a time. 72 pins are 32 – bit. SIMM’s are older technology, they are typically used for fast-paged and EDORAM. You are not as likely to find a SIMM with SDRAM, since dual inline memory module (DIMMs) were the prevalent from when SDRAM was introduced.
3. DIMM –Duel Line Memory module. DIMM modules look similar to SIMMs but are slightly longer and are inserted into a different type of slot. DIMM have two rows of connectors, 168 connectors in all, and are 64 bits.
DIMMs are likely to contain either EDO RAM or SDRAM because those technologies were common when DIMMs were introduced.

Put on Dim Slot Singly. Its called SDRAM also. Now This kind of Ram is use Widely.
3. RIMM –Rambus Inline Memory module. RIMM is designed specially for use with RAMBUS memory.
RIMMs look just like DIMMs but have 184 connectors. They are also more proprietary and less common than SIMMs and DIMMs. RIMMs are 16 bit.
4. SoDIMM – Small Outline DIMM Memory. This kind of memory module frequently used in LAPTOP Computers.
The physical size is much smaller then DIMM. The most common pin configurations are 72 and 144 pin modules.
5. MicroDIMM – The MicroDIMM is a module designed primarily for subcompact and portable computers.
The MicroDIMM is half the size of an SoDIMM and allows for higher density of storage. The MicroDIMM module is not keyed but will only install property one way.

Memory Bank –
The bit width of a memory module is very important; the term refers to how much information the processor can access from or write to memory in a single cycle. A memory Bank represents the number of memory modules required to much the data bus width of the processor.

Calculating Memory Bank Size –
1. Determine the data bus width of the processor in your computer (16 bits for a 386SX, 32 bits for a 386DX or 486, 64 bits for the Pentium family).
2. Determine the bit width of the memory module (30 pin SIMMs are 8 bit, 72 pin SIMM are 32 bit, DIMMs are 64 bit, and RIMMs are 16 bit).
3. Divide the processor’s data bus width by the memroy’s bit wdth . The number you get is the number of memory modules you must install to create one full bank.

Logical Memory:
1. SRAM : Static Random Access Memory
2. DRAM: Dynamic Random Access Memory

1. SRAM: It’s the first type of RAM available. It’s the memory of Processor. It is more expensive and Faster than DRAM. It needs a continuing Power supply. It does not require regular updating and refreshing by the CPU. SRAM is typically used only for system cache. Made by Lache Circuit, which is very expensive, for this Circuit it doesn’t need to be Refresh.

Processor

L1: Internal Processing. L1 has to take help from L2 for processing.
L2: L1 & L2 cannot work alone. They are depend on each other. L2 works for Network Processing.
L3: Middle Cache Memory. Its Optional. It speed up the power of RAM..

2. DRAM: DRAM chips provide much slower access than SRAM chips but can store several megabytes of data on a single chip. Because of its low cost and high capacity, DRAM is used as main memory in the computer.

a. EDORAM: Extended Data out RAM improves on traditional DRAM by performing more than one task at a time. When one piece of data is being sent to the processor, another is being retrieved from the RAM module. While that piece of data is being transferred the EDO RAM is looking for the next piece to retrieve for the processor. EDO Ram chips can only in a computer system whose processor and motherboard support its use.
b. SDRAM: Synchronous dynamic RAM or SDRAM, is about twice as fast as EDO RAM because it is able to run at the speed of the system bus(up to 100 –133MHz).
c. RDRAM: Rambus Dynamic Ram gets its name from the company that developed it, Rambus Inc. RDRAM can be used only in computers with special RDRAM channels and slots. RDRAM is fairly new, so don’t expect to see it in computers that were manufactured before 1999.
d. DDR: Double-data rate Ram doubles the rate of speed at which standard SDRAM can process data. That means DDR is roughly twice as faster as standard RAM.

These RAM are of two types-
DDR1- 1 nouch
DDR2- 2 nouch

e. VRAM: Video Ram is a specialized type of memory that is used only with video adapters. The video adapter is one of the computer’s busiest components, so to keep up with video requirements, many adapters have an on-board micro-microprocessor and special video RAM. Faster version of Video memory have been introduced, including WRAM.
f. WRAM: Window Ram is another type of video RAM but it provide faster access than VRAM.

Computer Parts

Devices of Computer

1. Mother Board –
2. Daughter Board –

Different Slot of Mother Board:

1. EISA/ISA Slot – VGA Card Black color (Large size)
2. AGP Slot – AGP Card Brown Color (Medium Size)
3. PCI Express Slot - PCI Express Card, Black Color - (Medium Size)
4. CNR Slot – 3 types of card (Sound Card, NIC/LAN Card, Modem(Internal)), Brown – (Small size)
5. Slot Processor Slot – SECC / Slot Processor
6. PCI Slot – Sound, AVG/VGA, TV Card, White Color – (Medium Size)

Port:
1. RJ45 – PC to PC/Hub/Switch Connection - RJ45 Connector
2. RJ11 – T.P/Modem – RJ11 Connector
3. BNCT – Sattelite/Dish Cable Connection

Connector:
1. RJ45 Connector – ASH Color - UTP Cable
2. RJ11 Connector – White Color - Two Pair Cable
3. BNCT Connector - Black Color – Co-axial Cable
4. Din Connector – White color – To Connect Mouse/ Keyboard

About Card:
7. Sound Card – Line In – Blue Color, Line Out – Green Color, Mice In – Pink Color, Game/Midi Port – Pink Color - DV25 port.
8. VGA/AGP/PCI Express Card – Interface DV15.

Processor:
Two type of Processor:
1. SECC Slot Processor
2. PGA /PLGA Socket Processor – Pin Grid Array/ Pixlen – Flatpin

Power Supply:
Three types of Ware:
1. ATX -
2. MOLEX -
3. BERG -

Modem:
Two Types:
1. Internal -
2. External -

HDD:
1. Platter:
2. Splinder:
3. Splinder Motor:
4. Voice Coial:
5. Armiteture:
6. Head of the Hard Disk:

Data Cable:
1. IDE(Integrated Data Interchange)/ATA Cable:
Two types:
a. 40 Pin –
b. 80 Pin –
2. SATA(Serial Advanced Technology Attachment):

Peripheral: The device which are connected to the CPU externally, are called Peripherals. Like – UPS, Monitor, Keyboard, Mouse.
Ports: The Peripherals are connected to the CPU or Motherboard by different Port.
1. PS2 (Personal System 2) Port –
a. Green Color – to connect Mouse
b. Parple Color – to connect Keyboard.
2. USB (Universal Serial Bus) Port –
a. USB device
b. Pendrive
c. USB data Cable
3. Serial Port – Its called Com (Commercial) Port .Its also called male Port. It has 9/25 pin. External Modem’s are connected to the 9 pin Serial Port.
4. CRT Port – Its called DB15 Port, and also Female port. The Cable of Monitor is connected with this port. The Cable is called CRT Cable.
5. Parallel Port – Its called LPT Port and also DB 25 Port. Its called female port also. To connect Printer this Port is Used widely. External Modem, CD Rom, Removable Cartridge, tape drive are also use this port.
6. IDE/ATA Cable Port or Slot – To connect Harddisk & CDRom by IDE/ATA Cable with the Motherboard his kind of port is used.
7. Floppy Cable Port - To connect Floppy drive by Floppy data Cable with Motherboard this type of Port is used.