Hi All, do anyone here have any idea of how to change the printer port for 8051 microcontroller into USB port.
"head of the cable is for printer port is that possible to change to USB?"
Almost certainly not - see the link I posted earlier.
You are going to have to Buy or Upgrade To a system that is designed to work on USB - it is most certainly not simply a matter of changing the connector!
"The cable is connected to the PC. Another end of the cable is connnected to the circuit itself."
What does the cable do? Is it simply for Flash programming, or does it also support debugging, etc? What PC software does it work with?