title: controling individual pins on a serial port
body: <p>I know that serial ports work by sending a single stream of bits in serial. I can write programs to send and receive data from that one pin.</p>
  
  <p>However, there are a lot more other pins on the serial port connection that normal aren't used but from documentation all seem to have some sort of function for signalling as opposed to data transfer.</p>
  
  <p>Is it possible in any way to cause the other pins that are not used for direct data transfer to be controlled individually? If so, how would i go about doing that?</p>
  
  <p>EDIT: more information</p>
  
  <p>I am working with a modern CPU running windows 7 64-bit on an intel core i7 870 processor. I'm using serial to usb ports because its imposable for me to do anything directly with a usb port and my computer does not come with serial ports and also for some inexplicable reason i have a bunch of these usb to serial port adapters lying around.</p>
  
  <p>My goal is to control mutipul stepper motors (200 steps per rotation, 4 phase motors). My simple circuitry accepts single high pulses and interprets it as a command to cause the motor to rotate one step. The circuit itself will handle the power supply and phase switching. I wish to use the data transfer pin to send the rotation signals (we can control position and velocity by altering the number of high pulses and frequency of high pulses through the pin, however there is no real pulse width modulation). </p>
  
  <p>I have many motors to control but they do not need to be controlled simultaneously. I hope to use the rest of the pins and run them through a simple combination logic circuit to identify which motor is being moved and which direction it is to move in. This is part of the power switching circuitry.</p>
  
  <p>The data transfer pin will operate normally at some low end frequency. However, i want to control the other pins to allow me to give a solid on or off signal (they wont be flipping very quickly, only changes when i switch to controlling another motor). </p>