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Tuesday, October 14, 2008

MoDeM..........

WhAt Is MoDeM???
Modem (from modulator-demodulator) is a device that modulates an analog carrier signal to encode digital information, and also demodulates such a carrier signal to decode the transmitted information. The goal is to produce a signal that can be transmitted easily and decoded to reproduce the original digital data. Modems can be used over any means of transmitting analog signals, from driven diodes to radio.
















A modem is a device or program that enables a computer to transmit data over, for example, telephone or cable lines. Computer information is stored digitally, whereas information transmitted over telephone lines is transmitted in the form of analog waves. A modem converts between these two forms.




TyPEs Of MoDeM..
The Carterfone decision
Before 1968, AT&T maintained a monopoly on what devices could be electrically connected to its phone lines. This led to a market for 103A-compatible modems that were mechanically connected to the phone, through the handset, known as acoustically coupled modems.













The Smartmodem and the rise of BBSes
The next major advance in modems was the Smartmodem, introduced in 1981 by Hayes Communications. The Smartmodem was an otherwise standard 103A 300-bit/s modem, but was attached to a small controller that let the computer send commands to it and enable it to operate the phone line. The command set included instructions for picking up and hanging up the phone, dialing numbers, and answering calls. The basic Hayes command set remains the basis for computer control of most modern modems.




Softmodem (dumb modem)
A Winmodem or Softmodem is a stripped-down modem that replaces tasks traditionally handled in hardware with software. In this case the modem is a simple digital signal processor designed to create sounds, or voltage variations, on the telephone line. Softmodems are cheaper than traditional modems, since they have fewer hardware components. One downside is that the software generating the modem tones is not simple, and the performance of the computer as a whole often suffers when it is being used. For online gaming this can be a real concern



Narrowband/phone-line dialup modems

A standard modem of today contains two functional parts: an analog section for generating the signals and operating the phone, and a digital section for setup and control. This functionality is actually incorporated into a single chip, but the division remains in theory. In operation the modem can be in one of two "modes", data mode in which data is sent to and from the computer over the phone lines, and command mode in which the modem listens to the data from the computer for commands, and carries them out. A typical session consists of powering up the modem (often inside the computer itself) which automatically assumes command mode, then sending it the command for dialing a number.



Monday, October 6, 2008

Luahan hati ku.....

hidup ini...
payah ditafsirkan....
kadangkala apa yang kita tidak duga,
akan kita tempuhi...
kadangkala apa yang kita tidak inginkan,
terpaksa kita hadapi....
walaupun sesukar mana ujian tersebut..
kita kena redha dan terus pandang kehadapan...

kadangkala...
kita akan dalam dilema
antara keluarga,teman dan diri sendiri...
mana yang patut kita pilih???
apakah yang terbaik untuk semua???
adakah berahsia akan menyelesaikan masalah???
tapi.....sampai bila??

oh....Tuhan...
tabahkanlah hatiku....
berikanlah aku kekuatan dalam menempuhi hidup ini...
hanya padaMu ku menghambakan diri....
kerana Engkaulah cinta hakiki....

Biar kesakitan meresapi dalam diri...
tapi.....janganlah kita turut 'mati'