Hardware Reference
In-Depth Information
24.
To be able to fit 133 minutes worth of video on a single-sided single-layer DVD, a fair
amount of compression is required. Calculate the compression factor required. As-
sume that 3.5 GB of space is available for the video track, that the image resolution is
720
480 pixels with 24-bit color (RGB at 8 bits each), and images are displayed at
30 frames/sec.
×
25.
Blu-ray runs at 4.5 MB/sec and has a capacity of 25 GB. How long does it take to read
the entire disk?
26.
A manufacturer advertises that its color bit-map terminal can display 2
24
different col-
ors. Yet the hardware only has 1 byte for each pixel. How can this be done?
27.
You are part of a top-secret international scientific team which has just been assigned
the task of studying a being named Herb, an extra-terrestrial from Planet 10 who has
recently arrived here on Earth. Herb has given you the following information about
how his eyes work. His visual field consists of about 10
8
pixels. Each pixel is basical-
ly a superposition of five ''colors'' (i.e., infrared, red, green, blue, and ultraviolet), each
of which has 32 intensities. The time resolution of Herb's visual field is 10 msec. Cal-
culate the data rate, in GB/sec, of Herb's eyes.
28.
A bit-map terminal has a 1920
1080 display. The display is redrawn 75 times a sec-
ond. How long is the pulse corresponding to one pixel?
29.
In a certain font, a monochrome laser printer can print 50 lines of 80 characters per
page. The average character occupies a box 2 mm
×
2 mm, about 25% of which is
toner. The rest is blank (i.e., no toner) The toner layer is 25 microns thick. The print-
er's toner cartridge measures 25
×
×
8
×
2 cm. How many pages is one toner cartridge
good for?
30.
The Hi-Fi Modem Company has just designed a new frequency-modulation modem
that uses 64 frequencies instead of just 2. Each second is divided into
n
equal time in-
tervals, each of which contains one of the 64 possible tones. How many bits per sec-
ond can this modem transmit, using synchronous transmission?
31.
An Internet user has subscribed to a 2-Mbps ADSL service. Her neighbor has sub-
scribed to a cable Internet service that has a shared bandwidth of 12 MHz. The modu-
lation scheme in use is QAM-64. There are
n
houses on the cable, each with one com-
puter. A fraction
f
of these computers are online at any one time. Under what condi-
tions will the cable user get better service than the ADSL user?
32.
A digital camera has a resolution of 3000
2000 pixels, with 3 bytes/pixel for RGB
color. The manufacturer of the camera wants to be able to write a JPEG image at a 5x
compression factor to the flash memory in 2 sec. What data rate is required?
33.
A high-end digital camera has a sensor with 24 million pixels, each with 6 bytes/pixel.
How many pictures can be stored on an 8-GB flash memory card if the compression
factor is 5x? Assume that 1 GB means 2
30
bytes.
34.
Estimate how many characters, including spaces, a typical computer-science textbook
contains. How many bits are needed to encode a book in ASCII with parity? How
many CD-ROMs are needed to store a computer-science library of 10,000 topics?
How many single-sided, dual-layer DVDs are needed for the same library?
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