I found an old USB to TTL (RS232) converter and I couldnt find the pin outs for it:

 

 

 

 

 

 

 

Based on the pins of the prolific chip I worked out that the pins on the left hand side correspond to: [use at your own risk]

 

1-

2-DTR

3-?RXD

4-

5-RTS

6-?TXD

7-

8-5V

9-

10-GND