How does the Scanner work.
The scanners are the eyes of the personal computer.
They allow the PC to convert a photo or picture into a code
so that a graphics program or desktop publishing to produce it on the screen, print it to a printer
graphical or convert typewritten pages in pages being editoradas possible.
The three main types of scanners
differ mainly as to the page (containing the image) and the scan head (that reads the image)
jogging.
On a sheet-fed scanner (sheet-fed), mechanical bearings move the paper through the scan head.
A flatbed scanner, the page is static over a glass, while the head moves across the page, as the machines
copiers.
The hand-held scanners depend on the human hand to move the scan head.
Each method has its advantages and disadvantages.
The flatbed scanner requires a series
Friday, February 28, 2014
Thursday, February 27, 2014
Interpreting the LEDs of the Modem
Interpreting the LEDs of the Modem.
The indicator lights (LEDs) on the front of an external modem inform what is happening during the session
communication. The location of the lights and the order in which they appear vary from one modem to another. But are usually identified by abbreviations composed of two letters. See below what they mean.
HS - The LED High Speed (High Speed) indicates that the modem is operating at its highest speed transmission.
AA - Led Auto Response (Auto Answer) indicates that the modem will automatically answer any calls. This
feature allows you to access your system even if it is not being monitored.
The indicator lights (LEDs) on the front of an external modem inform what is happening during the session
communication. The location of the lights and the order in which they appear vary from one modem to another. But are usually identified by abbreviations composed of two letters. See below what they mean.
HS - The LED High Speed (High Speed) indicates that the modem is operating at its highest speed transmission.
AA - Led Auto Response (Auto Answer) indicates that the modem will automatically answer any calls. This
feature allows you to access your system even if it is not being monitored.
Wednesday, February 26, 2014
The Modem.
The Modem.
1 - Your communications program sends a voltage across the 20 pin serial port, in which the modem is connected. The signal voltage is known as Data Terminal Ready (Data Terminal Ready) or simply DTR. This signal tells the modem that the PC was turned on and ready to transmit data. At the same time, the PC detects a voltage of the modem on pin 6 - a sign of Receiving Terminal Ready (Data Set Ready) or DST - which lets him know that the modem is ready to receive data or instructions. In normal connection, both signals must be present before something else can happen.
2 - Using a standard query language, called Hayes Hayes modems because it was in she became popular, the program communication sends a command to the modem via the line 2, line Data Transmission.
1 - Your communications program sends a voltage across the 20 pin serial port, in which the modem is connected. The signal voltage is known as Data Terminal Ready (Data Terminal Ready) or simply DTR. This signal tells the modem that the PC was turned on and ready to transmit data. At the same time, the PC detects a voltage of the modem on pin 6 - a sign of Receiving Terminal Ready (Data Set Ready) or DST - which lets him know that the modem is ready to receive data or instructions. In normal connection, both signals must be present before something else can happen.
2 - Using a standard query language, called Hayes Hayes modems because it was in she became popular, the program communication sends a command to the modem via the line 2, line Data Transmission.
Tuesday, February 25, 2014
How the Modem Works
How the Modem Works.
Your Pc is a digital device. He performs most tasks by turning a series of electronic switches.
A binary 0 - represented here by a sphere - indicates a button off. A binary 1 - here represented by a cube
- Indicates a button on. There is no intrinsic distinction. The design of a digital code would look like this:
The phone system is an analog device, designed - at a time when digital electronics was unknown - for
convey the various sounds and tones of the human voice. These sounds are electronically converted into an analog signal as a continuous current that varies gradually power and frequency.
Your Pc is a digital device. He performs most tasks by turning a series of electronic switches.
A binary 0 - represented here by a sphere - indicates a button off. A binary 1 - here represented by a cube
- Indicates a button on. There is no intrinsic distinction. The design of a digital code would look like this:
The phone system is an analog device, designed - at a time when digital electronics was unknown - for
convey the various sounds and tones of the human voice. These sounds are electronically converted into an analog signal as a continuous current that varies gradually power and frequency.
Monday, February 24, 2014
Mechanical Mouse
Mechanical Mouse.
Here is how the mouse translates your hand movements into actions on the screen.
1 - When moving a mechanical mouse dragging a flat surface, a ball - made of rubber or steel covered with
Rubber - protruding slightly out of the bottom of the mouse rotates the direction of motion.
2 - As the ball rotates it touches and moves the two bearings positioned at an angle of 90 degrees from each other. A bearing responds by movements back and forward mouse, corresponding to the vertical movement across the screen. The other responds by lateral movements, corresponding to horizontal movement on the screen.
Here is how the mouse translates your hand movements into actions on the screen.
1 - When moving a mechanical mouse dragging a flat surface, a ball - made of rubber or steel covered with
Rubber - protruding slightly out of the bottom of the mouse rotates the direction of motion.
2 - As the ball rotates it touches and moves the two bearings positioned at an angle of 90 degrees from each other. A bearing responds by movements back and forward mouse, corresponding to the vertical movement across the screen. The other responds by lateral movements, corresponding to horizontal movement on the screen.
Tuesday, February 18, 2014
How the Mouse Works.
How the Mouse Works.
There is nothing natural or intuitive on a keyboard. No child is born knowing how to type and even come to know, there is not much sense of it - no one can explain satisfactorily why the alphanumeric keys are
the way they are arranged.
For many, the keyboard is still a barrier to learning to use a computer. Even more to the digitizer
experienced, there is nothing intuitive in type / FS to write a file in Lotus 1-2-3. Engineers - sure
none a great typist - Research Center Palo Alto (PARC) of Xerox Corporation developed a
concept first explored by Douglas C. Engelbert of Stanford Research Center. The concept was a
pointing device, something that the user could move with his own hand, producing a corresponding movement in the screen.
There is nothing natural or intuitive on a keyboard. No child is born knowing how to type and even come to know, there is not much sense of it - no one can explain satisfactorily why the alphanumeric keys are
the way they are arranged.
For many, the keyboard is still a barrier to learning to use a computer. Even more to the digitizer
experienced, there is nothing intuitive in type / FS to write a file in Lotus 1-2-3. Engineers - sure
none a great typist - Research Center Palo Alto (PARC) of Xerox Corporation developed a
concept first explored by Douglas C. Engelbert of Stanford Research Center. The concept was a
pointing device, something that the user could move with his own hand, producing a corresponding movement in the screen.
Monday, February 17, 2014
Parallel port.
Parallel port.
1 - A signal line 13 for PC - known as line selection - coming from the peripheral, usually a printer,
tells the computer that the printer is active and ready to receive data.
tells the computer that the printer is active and ready to receive data.
Wednesday, February 12, 2014
O URL http:// está bloqueado. Google Chrome.
O URL http:// está bloqueado.
Google Chrome.
Alguém sabe porque no google chrome algumas páginas tem aparecido com a seguinte mensagem:O URL http:// está bloqueado.
Grato,
Source: Evolution of Computers
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