8-46. 8-47. 8-48. 8-49. 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 In parallel data operations, one I/O channel could consist of which of the following devices? 1.  Two  cables,  one  for  input  and  one  for output  or  a  single  cable  to  handle  both input  and  output 2.  Eight  or  more  data  lines 3.  A  number  of  control  lines 4.  All  of  the  above 8-50. The data strobe in single parallel cable operations is used for which of the following purposes? 1.  Checks  for  data  on  the  data  lines 2.  Ensures  that  the  data  on  the  data  lines is stable 3.  Signals  the  external  device  that  data  is ready  to  be  read  from  the  data  lines 4.  All  of  the  above 8-51. In single parallel cable operations, a busy signal would be sent under which of the following conditions? 1. 2. 3. 4. The computer output buffer is full The external equipment is not energized The external equipment input buffer is full The computer is involved in internal operations 8-52. In two cable parallel operations, an external interrupt enable can be described as which of the following? 1.  A  signal  sent  from  the  external  device on  the  input  line 2.  A  signal  sent  from  the  computer  on the  output  line 3.  A  signal  sent  from  the  external  device on the output line 4.  A  signal  sent  from  the  computer  on the input line 8-53. 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 67