Information Technology Reference
In-Depth Information
reset_vectors();
return(0);
}
16.6 Exercises
16.6.1
How many pins does a standard D-type parallel port connector have:
(a)
9
(b)
12
(c)
25
(d)
36
16.6.2
How many data bits can the parallel port transmit at a time:
(a)
8
(b)
12
(c)
16
(d)
32
16.6.3
What is the major limitation of a standard Centronics parallel port:
(a)
It is only an output
(b)
It is not compatible with many printers
(c)
Incompatibility of software (d)
Limited cable types
16.6.4
What is the maximum data of a standard Centronics parallel port:
(a)
15 kbps
(b)
150 kbps
(c)
1.5 Mbps
(d)
10 Mbps
16.6.5
What is the standard I/O base address for a standard parallel port:
(a)
3F8h
(b)
378h
(c)
2F8h
(d)
278h
16.6.6
What is the standard I/O base address for a secondary parallel port:
(a)
3F8h
(b)
378h
(c)
2F8h
(d)
278h
16.6.7
What is the standard interrupt line for a standard parallel port:
(a)
IRQ3
(b)
IRQ4
(c)
IRQ5
(d)
IRQ7
16.6.8
Write a program that sends a 'walking-ones' code to the parallel port. The delay
between changes should be 1 second. A 'walking-ones' code is as follows:
