You can easily generate a PWM signal to drive a Victor, Jaguar, or Talon using the RTS & DTR pins of the RS232 serial port on an old junker laptop with an early Pentium or 486 processor.
This paper describes a simple method of logging diagnostic data through the Robot Controller’s second serial port. The concept is to add a FLASH memory based serial logger to the RC, and provide a simple software macro for sending data to the logger.
There's no crying in robotics! - TubaMorg [more] 
