Glossary

a PC chipset provides the electronic interfaces between all subsystems.

CMOS (complementary metal-oxide semiconductor)

CMOS is a widely used type of semiconductor, which features high speed and low power consumption. PCs usually contain a small amount of battery-powered CMOS memory to retain the date, time, and system setup parameters.

COM

In MS-DOS system, the name of a serial communications port. DOS supports four serial ports. For example, if a modem is connected to one serial port and a serial mouse to another, they are identified as COM1 and COM2.

DIMM (dual in-line memory module)

A small circuit board that holds memory chips. A SIMM (single in-linememory module) has a 32-bit path to the memory chips whereas a DIMM has 64-bit path.

DMA (direct memory access)

A transfer mode between the main memory and the peripheral devices that without passing through the CPU. Using the DMA controller, data is transferred much faster.

DRAM (Dynamic RAM)

A most common type of computer memory. It usually uses one transistor and a capacitor to represent a bit. As the development of technology, the memory type and specification used in computer becomes variety, such as SDRAM, DDR SDRAM, and RDRAM. For further instruction, please see the table below:

Dynamic RAM (DRAM) Memory Technologies

Type

First Used

Clock Rate

Bus* Width

Peak

Volts

 

 

 

 

Bandwidth

 

FPM (60,70ns)

1990

25MHz

64 bits

200

MBps

5v

EDO (50,60,70ns)

1994

40MHz

64 bits

320

MBps

5v

SDRAM (66MHz)

1996

66MHz

64 bits

528

MBps

3.3v

SDRAM (100MHz)

1998

100MHz

64 bits

800

MBps

3.3v

SDRAM (133MHz)

1999

133MHz

64 bits

1.1 GBps

3.3v

RDRAM (Direct Rambus)

1999

400MHz

16 bits

1.6 GBps

2.5v

 

 

 

 

 

 

DDR SDRAM (100MHz)

2000

100MHz

64 bits

1.6 GBps

3.3v

DDR SDRAM (133MHz)

2000

133MHz

64 bits

2.1 GBps

3.3v

* Memory channel width (64 bits started with 75MHz Pentium)

Source: Computer Desktop Encyclopedia

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Image 65
Microstar G52-MA00514 manual Dynamic RAM Dram Memory Technologies