Workshop Day 01 (Hardware for Dummies)

Hi back after sometime, today I heard the good news that Truptiben , Rakeshbhai and Dhilan are coming for 90days to India, I am very excited. Well today i attended the first of 2 days workshop on hardware maintenance. I would like to share with everyone all that I learnt.

First things first ,lets list out the parts inside a CPU:

1. Switch mode power supply (SMPS)
2. Motherboard
3. Processor
4. RAM
5. Add on cards like graphics card, sound card, etc
6. Storage Device like Hard disk, CDROM, etc
7. Cooling mechanism like a fan,etc
8. Cabinet
   
9. Cables

Motherboard is a very important part of the CPU, motherboard changes according to the processor. The motherboard is used to connect all the different parts of the CPU. Every motherboard has a speed, devices cannot communicate with each other higher than the motherboard speed.

There is a CPU socket on every motherboard for the processor slot, the P3 processor is 370 pin and P4 processor is 478 pin. The latest processors like Core 2 Duo are pinless, pins are present on socket not processor. Again as I mentioned each processor requires a different type of motherboard.

BACK OF PENTIUM 3 PROCESSOR

There are 2 types of primary memory, RAM and ROM.
ROM: BIOS (Basic INput Output System) is stored in ROM. BIOS contains the following:

1. POST (Power on Self Test)
2. CMOS PRogram
3. CMOS RAM (used to save CMOS data)
4. Boot Strap Loader to load OS into memory.

ROM

There is a small chip of BIOS on motherboard. BIOS programming is done according to structure of motherboard. ROM nowadays are composed of flash memory, earlier they were semiconductor chips. The history of ROM is as follows:

* Programmable read-only memory (PROM), or one-time programmable ROM (OTP), can be written to or programmed via a special device called a PROM programmer. Typically, this device uses high voltages to permanently destroy or create internal links (fuses or antifuses) within the chip. Consequently, a PROM can only be programmed once.

BIOS

* Erasable programmable read-only memory (EPROM) can be erased by exposure to strong ultraviolet light (typically for 10 minutes or longer), then rewritten with a process that again requires application of higher than usual voltage. Repeated exposure to UV light will eventually wear out an EPROM, but the endurance of most EPROM chips exceeds 1000 cycles of erasing and reprogramming. EPROM chip packages can often be identified by the prominent quartz "window" which allows UV light to enter. After programming, the window is typically covered with a label to prevent accidental erasure. Some EPROM chips are factory-erased before they are packaged, and include no window; these are effectively PROM.

* Electrically erasable programmable read-only memory (EEPROM) is based on a similar semiconductor structure to EPROM, but allows its entire contents (or selected banks) to be electrically erased, then rewritten electrically, so that they need not be removed from the computer (or camera, MP3 player, etc.). Writing or flashing an EEPROM is much slower (milliseconds per bit) than reading from a ROM or writing to a RAM (nanoseconds in both cases), since available densities are not as great and the cost per bit is higher.

o Electrically alterable read-only memory (EAROM) is a type of EEPROM that can be modified one bit at a time. Writing is a very slow process and again requires higher voltage (usually around 12 V) than is used for read access. EAROMs are intended for applications that require infrequent and only partial rewriting. EAROM may be used as non-volatile storage for critical system setup information; in many applications, EAROM has been supplanted by CMOS RAM supplied by mains power and backed-up with a lithium battery.

o Flash memory (or simply flash) is a modern type of EEPROM invented in 1984. Flash memory can be erased and rewritten faster than ordinary EEPROM, and newer designs feature very high endurance (exceeding 1,000,000 cycles). Modern NAND flash makes efficient use of silicon chip area, resulting in individual ICs with a capacity as high as 16 GB as of 2007; this feature, along with its endurance and physical durability, has allowed NAND flash to replace magnetic in some applications (such as USB flash drives). Flash memory is sometimes called flash ROM or flash EEPROM when used as a replacement for older ROM types, but not in applications that take advantage of its ability to be modified quickly and frequently.


RAM: It stands for Random accesss memory, it is the memory used by the processor to execute the program. There are two factors of RAM, capacity and speed.

RAM CHIPS

P3 had SDRAM which has 2 notches on it.
P4 had DDR1 RAM with 1 notch on ot.

MOst of us now use DDR2 RAM and DDR3 RAM is also now introduced.

There are 2 types of RAM, SRAM and DRAM. Static and Dynamic RAM respectively. SRAM is made up of flip flops and is used as cache memory with a maximum size of 4MB. DRAM is made up of capacitors and is used in RAM chips, the primary memory. Nowadays cache memory is present in processor ,earlier it was on motherboard.

SRAM is faster and costlier than DRAM, but both are used in any given machine. Normally programs and not data are stored in cache memory.

DRAM are of 3 types SDRAM, DDRSDRAM and RDRAM. SDRAM were used in P3 with speeds having 66, 100 and 133 Mhz. DDRSDRAM are Double data rate SDRAM with speeds of 266MHz and above, DDR1, DDR2 and DDR3 come under these category. RDRAM is very expensive.


Chipset: A chipset is m ade up of a number of chips require to run a CPU like for eg. a chipset may typically contain 8088, 8086, 8255, 8259, etc chips. PRocessor, memory and graphics are controlled by chipset on motherboard. It controls flow of data.

CHIPSET

There are 2 types of chipset: GMCH (Graphic memory control hub) and ICH (input output control hub).

Well this was all I learnt in today's 2 hour workshop and I hope this must be helpful to you, you can post any comments or questions u need.

Thank You.