8-44. The protective ground, pin 1, of the RS-232
8-45.
8-46.
8-47.
8-48.
interface connector in the DTE/DCE mode should
always be connected to the shielded cable shield
at both ends.
1. True
2. False
Pin 7 of the RS-232 interface connector in the
DTE/DCE mode should always be connected at
both ends for which of the following reasons?
1.
2.
3.
4.
To complete the path for control signals only
To provide a complete path for the data
signals only
To provide timing signals to the peripheral
device only
To provide a common reference for all
signals
Pin 3 of the RS-232 interface connector in the
DTE/DCE mode is used for which of the
following purposes?
1. To send data signals
2. To send control signals
3. To receive data signals
4. To receive control signals
Pins 4,5,6, and 20 are used in the DTE/DCE
mode using the RS-232 interface connector for
which of the following purposes?
1. To send and receive data signals
2. To send and receive control signals
3. To send and receive timing signals
4. To establish the communications link
In parallel data operations, the IOA or line
driver/receiver provides the means to accomplish
which of the following tasks?
1. Convert the byte or word to a sequential bit
stream
2. Drive or detect the digital signals
3. Convert serial data to parallel data
4. Provide constant timing signals at the
specified voltage levels
8-49.
8-50.
8-51.
8-52.
8-53.
In parallel data operations, one I/O channel could
consist of which of the following devices?
1.
2.
3.
4.
Two cables, one for input and one for output
or a single cable to handle both input and
output
Eight or more data lines
A number of control lines
All of the above
The data strobe in single parallel cable operations
is used for which of the following purposes?
1.
2.
3.
4.
To check for data on the data lines
To ensure that the data on the data lines is
stable
To signal the external device that data is
ready to be read from the data lines
All of the above
In single parallel cable operations, a busy signal is
sent under which of the following conditions?
1. The computer output buffer is full
2. The external equipment is not energized
3. The external equipment input buffer is full
4. The computer is involved in internal
operations
In two-cable parallel operations, an external
interrupt enable can be described as which of the
following signals?
1. A signal sent from the external device on the
input line
2. A signal sent from the computer on the output
l i n e
3. A signal sent from the external device on the
output line
4. A signal sent from the computer on the input
line
When an external interrupt code is placed on the
data lines, it is accompanied by which of the
following signals?
1. An external interrupt request
2. An input data acknowledge
3. An input data request
4. All of the above
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