How can i activate the serial port on OS X 10.9.2?

The device you bought looks like the Plugable adapter I bought, which is based on Prolific PL2303, so you just need to know what the tty for the serial device is. The drivers on the Plugable site says 10.6 or greater, so maybe try those.

http://plugable.com/products/pl2303-db9

In my case, its /dev/tty.usbserial. If you want to just connect to a switch, install the drivers and use screen like so:

screen <serial device> <baud rate>

ex:

screen /dev/tty.usbserial 115200

Who makes the serial port, and do they supply a driver for Mavericks? I just looked at a Prolific product and it seems to only be for Windows.

We just released a new Mac app called Serial- it's a terminal emulator that works with USB to serial devices without requiring you to install any drivers in most cases, as we're able to talk to the most common USB to serial devices directly. It's available on the app store and there's a free demo on our website. Link: http://www.decisivetactics.com/products/serial

I know it uses a Prolific chipset, but I don't know that means the driver you found will necessarily work. This is from the questions section on that device:

http://www.amazon.com/adapter-work-Macbook-running-10-8-5/forum/Fx2HTE8NIDII1F7/ Tx1ECOBWAMC32ME/1/ref=cm_cd_dp_aar_al_a?_encoding=UTF8&asin=B0007OWNYA

It's saying the device will work up to 10.8.5

I have no idea. Serial ports are fairly rare anymore to begin with, so it all depends on finding a vendor that supports Mavericks.

This might help you.

http://robpickering.com/2013/12/enabling-a-usb-to-serial-port-adapter-under-os-x -10-9-mavericks-1623