CABLE DESIGN LEGEND:  The diagrams should be interpreted as follows:

 DEVICE-1   DEVICE-2   The cable is viewed from end to end, with the DEVICE-1 
 ------------------    end to be connected to the port on DEVICE-1, and the
   2 --------- 3       DEVICE-2 end connected to the port on DEVICE-2.
   3 <-------- 2      In the example on the left, pin 20 at the DEVICE-1 end of
   4 --|-----> 8      the cable should be connected straight through to pin 20
   5 <-|              of the DEVICE-2 end. Pin 2 at one end should be connected
  20 --------- 20     to pin 3 at the other end.  Pin 4 from DEVICE-1 should be
                      connected to pin 5 at the same end, as well as pin 8 at
                      the DEVICE-2 end of the cable.  
SPECIAL NOTE:  If a straight through cable has been designed(pins 1--1, 2--2,
  3--3, 4--4, 5--5,...etc., not all pins in the design are necessary.  This
  design is given for completeness.  A general rule is: if the lead is not
  present in both DEVICE 1 & 2's ports, there is no need to include it.  Yet 
  a flat/ribbon cable with all 25 leads should be used for ease & completeness.
MODEMS TO COMPUTERS:  The straight through cable includes connecting pins 22,
  Ring Indicator, at both ends.  Unless a modem is being connected to a DEVICE,
  these pins are probably not needed.  In the case of an IBM AT to modem cable,
  connect pin 9 at the AT end to pin 22 at the modem end of the cable.
SYNCHRONOUS CONNECTIONS:  Ignore Pins 15, 17, & 24 of a straight through cable
unless it is being designed to connect a device and modem for synchronous
communication.  
.....PRESS ANY KEY TO CONTINUE
