DMAN

A dot matrix printer or impact matrix printer is a type of  computer printer with a print head that runs back and forth on the page and prints by impact, striking an ink-soaked cloth ribbon against the paper just like a typewrighter. However unlike a typewriter letters are drawn out of a dot matrix, and varied fonts and arbitrary graphics can be produced. Because the printing involves mechanical pressure, these printers can create carbon copies.

The dot matrix printer has got:

• Fast Speed – 300 cps Draft Micron and 100 cps LQ
• High Carbon Capacity – Original plus 4 non-carbon copies
• Long-life Ribbon – 6 million character life in Draft Mode
• Serial and Parallel Interfaces and Selectable Buffer (1 KB/8 KB/22 KB [Factory Default]/54 KB)
• 6 Scalable / 3 Draft / 7LQ fonts
• Set-up and Driver disk for Windows 3.1 & Windows 95 included

CAUTION: Be sure to unplug the printer from the electrical source before beginning any type of maintenance.

A laser printer is a common type of computer printer that quickly produces high quality text and graphics on paper. As with digital copiers and multifunction pirinters, laser printers employ a xero graphic printing process but differ from analog photo copiers in that produced by the direct scanning of a laser beam across the printer’s photoreceptor.Laser printers have many significant advantages over other types of printers. Unlike impact printers, laser printer speed can vary widely, and depends on many factors, including the graphic intensity of the job being processed. The fastest models can print over 200 monochrome pages per minute 12,000 pages per hour. There are three main technologies in use in contemporary inkjet printers: thermal, piezoelectric, and continuous.

A thermal printer produces a printed image by selectively heating coated thermochromic paper, or themal paper as it is commonly known, when the paper passes over the thermal print head. The coating turns black in the areas where it is heated, producing an image. Two-color direct thermal printers are capable of printing both black and an additional color often red, by applying heat at two different temperatures.

A thermal printer comprises these key components:

• Thermal head — generates heat; prints on paper
• Platen — a rubber roller that feeds paper
• Spring — applies pressure to the thermal head, causing it to contact the thermo-sensitive paper
• Controller boards — for controlling the mechanism

One of the original laptops was the GRiD it was used by astronauts on space missions in the early 1980s and it weighed 5kg also it US $8,000 – $10,000!

old laptop

Laptops:
Early laptops were heavy and expensive. Today, laptops are popular because advances in technology have resulted in laptops that cost less, weigh less, and have improved capabilities.

PDAs and Smartphones:
PDAs and Smartphones are examples of portable, hand-held devices that are becoming more popular. PDAs offer features such as games, web surfing, e-mail’s.

The PDA is an electronic personal organizer with tools to help organize information:

• Address book
• Calculator
• Alarm clock
• Internet access
• E-mail
• Global positioning
  
• 
  

Smartphones may include these additional options:

• Built-in camera
• Document access
• E-mail
• Abbreviated note-taking
• Television
  
• 

Can you think of other uses for the PDA and the Smartphone?

http://www.youtube.com/watch?v=8qCtZ7EJRfo

http://www.youtube.com/watch?v=gplUFHH85I

What are some common laptop features?

There are two methods of power management:

• Advanced Power Management (APM)
• Advanced Configuration and Power Interface (ACPI)

A laptop hard drive use less power than a desktop hard drive.

A laptop mother board is much smaller and lighter and the desktop mother board is big and heavy and hard to carry around.

Most of the functions that a desktop can perform can also be performed by a laptop. However, these two kinds of computers are built very differently and the parts are not interchangeable.

Laptop components are much more specialized than desktop components. This difference is because laptop manufacturers focus on refining laptop components to make them more efficient and compact.

The components for a laptop are:

• Battery
• Optical drive
• Hard drive
• Memory
• PC cards

The standars for a Power Management and ACPI are:

• SO: The computer is on and the CPU is running.
• S1: The computer is not running. However the CPU and RAM are still receiving power.
• S2: The CPU is off, but the RAM is refreshed. The system is in a lower mode than S1.
• S3: The CPU is off, and the RAM is set to a slow refresh rate. This is called SAVE RAM.
• S4: The CPU and RAM are off. The contents of RAM have been saved to a tempatorary file on the hard disk. This is called SAVED TO DISK.
  
• S5: The computer is off and nothing is saved.
  

Remove the battery from the battery bay:

1. Move the battery lock to the unlocked position.
2. Hold the release lever in the unlock position and remove the battery.

Install the battery into the battery bay:

1. Insert the battery.
2. Make sure that both battery levers are locked.

1. Remove screw to expose the SODIMM.
2. Press outward on the clips that hold the sides of the SODIMM.
3. Lift up to loosen the SODIMM from the slot and remove the SODIMM.

Install the SODIMM:

1. Align the notch at a 45-degree angle.
2. Gently press down until clips lock.
3. Replace cover and install screw.

The first generation (1G) of cell phones began service in the 1980s. First-generation phones primarily used analog standards, including Advanced Mobile Phone System (AMPS) and Nordic Mobile Telephone (NMT).

n the 1990s, the second generation (2G) of cell phones was marked by a switch from analog to digital standards. Second-generation cell standards included Global System for Mobile (GSM).

It is also common for 3G cell phones to access the Internet and to use the Global Positioning System (GPS).

Fourth-generation (4G) standards have been championed by many users, in response to the availability of increased data rates. Higher data rates will allow users to download files, such as video and music, faster than what was available with standards of previous generations.

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