1.a. What are some ways people use computers in the home, at work, and at
school?
The uses of computers include education, self-improvement,
correspondence, communication, information gathering, ordering goods and
services, banking,
entertainment, planning, business,
finance, commerce, illustration, interactive instruction, archiving, and other
tasks.
1.b. What does it mean to be computer literate?
Being computer literate means you have knowledge and understanding of
computers and their uses.
2. a. How is hardware different from software?
Hardware is the collection of physical components that are used to make the
computer.
Software is the set of instructions that tell the stored program computer
what to do.
2. b. Why is hardware useless without software?
Without instructions, the stored program computer cannot perform any tasks.
Digital logic hardware is not always useless without software. Not all logic devices are general purpose computers. When you take a
course in digital logic, you will construct
some simple logic devices that do simple tasks without using a stored program. Examples of useful digital
hardware without software: digital clock, simple alarm systems, simple elevator
control logic, simple automobile engine electronic ignition.
3. a. What is a peripheral device?
Any external device that attaches to the system unit is called a peripheral
device.
3. b. What hardware components are considered peripheral devices? (Page
4.23): Device that connects to a system unit and is controlled by the processor
in the computer.
Components such as the keyboard, mouse, microphone, monitor, PC camera,
digital camera, scanner, and
printer are located external to the system unit.
A peripheral device is one that is not part of the basic architecture of the
system. It often requires interfacing hardware and software to permit the
computer to use the device.
On main frame computers, the CPU and memory make up the computer. Disk
drives, tape drives, printers, and display units are peripherals.
4. a. What are six common secondary storage devices?
Common secondary storage devices include hard disk, 3.5-inch floppy disk, Zip Disk, CD-ROM, DVD-ROM,
CD-RW drive, magnetic tape cartridge,
cassette magnetic tape.
The terms "primary storage" and "secondary
storage" have their origin in a two-tiered storage system where
"primary storage" referred to magnetic core and "secondary
storage" referred to all other storage devices. The primary
difference is the order of magnitude difference in average access time.
Primary Storage is storage accessed by the processor as the primary immediate
source of instructions from a stored program, and is the preferred source for
frequently accessed data.
Storage systems are now multi-tiered. In an
arms-race style battle, computer engineers are on a never-ending quest to
increase the rate of completion of execution of instructions. One strategy
has been to insert faster (and thus more expensive, and therefore smaller
capacity) memory units to speed-match between primary storage and processors and
devices. Such an additional memory unit is called a "cache"
(like the Eskimo cache of fish).
4. b. How are they different?
Storage devices differ in physical method of data storage, physical method of
reading data, capacity, density, access speed, longevity, removeability, dimensions, and cost.
Magnetic storage media include: hard drive, 5.25-inch floppy, 3.5-inch
floppy, zip disk, magnetic tape, cassette tape.
CDs store data by microscopic pits made in the recording media
using
a laser. Therefore, the shape of the recording media is altered at the
spot where the pit is made. This is a topological change. CDs are read by a
low
power laser. CD-R records by heating an organic dye to make a spot opaque, which reflects
less light. CD-RW records by heating a crystalline compound.
Use of one power setting causes the compound to become crystalline when it
cools; a higher power causes it to become amorphous when it cools.
Reading is done by a low power laser. Well-reflected
light is read as a "1". Otherwise, it is read as a
"0".
It is common today for a hard drive to have larger storage capacity that
either a CD or DVD disk. Typical storage capacities are
CD and DVD are much slower than a hard disk for data transfer.
Short Answer Question #4B CLICK
for Storage Device Summary.
The CD-ROM is recorded by using a laser to burn microscopic pits into the
recording surface.
When recording, CD-R, CD-RW use a laser as a heat source to cause a chemical
reaction. Learn more in the lesson plan on storage devices.
5. a. Why do people use the Internet?
People use the Internet for communication, information retrieval, commerce,
conferencing, entertainment, and occasionally education. Many courses are
available over Internet. See The World Lecture Hall at http://www.utexas.edu/world/lecture/
.
5. b. How do most users connect to the Internet?
Most users connect to the Internet through computers at work or school.
These usually have a dedicated line connection via a local area network.
Home users usually connect through a local dial-up point of presence to an
Internet Service Provider via a modem connection. Some Internet service
providers are national companies such as America On Line or Microsoft
Network. The cost of such a connection is market driven, and is sometimes
related to the service you receive.
The entertainment cable industry is changing from simplex to duplex
operation, allowing subscribers to connect to the Internet through the same
cable service used for cable TV. This includes the Time-Warner Cable Road Runner, Media One, Cox, Bend, Multimedia, and the @home cable modem networks.
For more information, visit http://usmcug.usm.maine.edu/~kpesce/rr/
.
