Summing this issue up, it is most likely going to be a driver issue. And until we know which serial chip your Prolific cable is using there is not much we can do in the way of selecting your CHIRP serial driver.

Alternately what you can do is try each Prolific drivers identified in the following two headings at CHIRP’s document  Mac USB Drivers:
  1. Prolific PL-2303 cables - official drivers for the genuine Prolific cables
  2. Generic PL-2303 cables (counterfeit and/or “Generic”)
Pete

On May 29, 2014, at 7:55 PM, Jeff Grantham <jeff@kb5wck.com> wrote:

I honestly don't remember.  I bought it years ago.  

From: Pete Mackie <pete@seaquest.com>
Reply-To: Discussion of CHIRP <chirp_users@intrepid.danplanet.com>
Date: Thursday, May 29, 2014 9:52 PM
To: Discussion of CHIRP <chirp_users@intrepid.danplanet.com>
Subject: Re: [chirp_users] Chirp vs. Win8.1

Is your Prolific cable a Chinese clone—with know bugs in the serial chip—or a Prolific cable built and sold by Prolific?

there is a big difference between these two Prolific cables.

73 for the evening.
Pete