Sound Systems

Multimedia PCs generally come with sound systems, which include a sound card, speakers, a CD-ROM or DVD drive, and a video controller.

Printers

Printers fall into two general categories: impact and nonimpact. Impact printers create an image on paper by using a device to strike an inked ribbon, pressing ink from the ribbon onto the paper. Nonimpact printers use various methods to place ink (or another colored substance) on the page.

When evaluating printers for purchase, you should consider four criteria: image quality, speed, initial cost, and cost of operation.

A dot matrix printer is a common type of impact printer. A dot matrix printer uses a print head, which contains a cluster of pins. The printer can push the pins out to form patterns, in rapid sequence. The pins are used to press an inked ribbon against paper, thus creating an image. The lowest resolution dot matrix printers have an array of nine pins; the highest resolution dot matrix printers have twenty-four pins. The speed of dot matrix printers is measured in characters per second.

An ink jet printer is an example of a nonimpact printer. It creates an image by spraying tiny droplets of ink onto the paper. Ink jet printers are inexpensive for both color and black printing, have low operating costs, and offer quality and speed comparable to low-end laser printers.

Laser printers produce higher-quality print and are fast and convenient to use, but they are also more expensive than ink jet printers. Laser printers are nonimpact printers. They use heat and pressure to bond tiny particles of toner (a dry ink) to paper. Laser printers are available in both color and black and white, and the highest end laser printers provide resolutions of 1200 dpi and greater.

Snapshot printers are specialized, small-format printers used to print small color photographs. Snapshot printers are popular among users who own digital cameras. Snapshot printers are fairly slow, and they can be more expensive to operate than standard ink jet or laser printers.

Thermal-wax, dye-sublimation, fiery, and IRIS printers are used primarily by print shops and publishers to create high-quality color images.

Plotters create large-format images, usually for architectural or engineering purposes, using mechanical drawing arms, ink jet technology, or thermal printing technology.

Types of Storage Devices

Storage devices can be categorized as magnetic or optical. The most common magnetic storage devices are diskettes, hard disks, high-capacity floppy disks, disk cartridges, and magnetic tape. The primary types of optical storage are compact disk read-only memory (CD-ROM), digital video disk read-only memory (DVD-ROM), CD-Recordable (CD-R), CD-ReWritable (CD-RW), DVD-Recordable (DVD-R), DVD-ReWritable (DVD-RW) and PhotoCD.

Magnetic Storage Devices

Magnetic storage devices work by polarizing tiny pieces of iron on the magnetic medium. Read/write heads contain electromagnets that create magnetic charges on the medium. Diskette drives, also known as floppy disk drives, read and write to diskettes. Diskettes are used most often to transfer files between computers, as a means for distributing software, and as a backup medium. 3.5 inches diskettes are available at present. Before a magnetic disk can be used, it must be formatted – a process that maps the disk's surface and creates tracks and sectors where data can be stored. When a disk is formatted, the operating system creates four distinct areas on its surface: the boot sector, FAT, root folder, and data area.

Hard disks can store more data than diskettes because of their higher-quality media, faster rotational speed, and the tiny distance between the read/write head and the disk's surface. Removable hard disks combine high capacity with the convenience of diskettes.

High-capacity floppy disks are becoming a popular add-on for many computers. They offer capacities up to 250 MB and the same portability as standard floppy disks.

Data cartridges are like small removable hard disks and can store up to 200 GB.

Magnetic tape systems offer slow data access, but because of their large capacities and low cost, they are a popular backup medium.

Optical Storage Devices

CD-ROM uses the same technology as a music CD does; a laser reads lands and pits on the surface of the disk. Standard CD-ROM disks can store up to 700 MB. Once data is written to the disk, it cannot be changed.

DVD-ROM technology is a variation on standard CD-ROM. DVDs offer capacities up to 17 GB.

Other popular variations on CD-ROM and DVD-ROM are CD-Recordable, CD-ReWritable, DVD-Recordable, DVD-ReWritable and PhotoCD.