I really want to learn how to do parallel/serial port programming on my Mac. Now I know I'd have to buy a USB adapter, but it seems like it's so much easier on PCs than it is on Macs. I just saw this article about a light show you can setup with a circuit board that connects to your Parallel port. If you look at the Linux source, it's very simple. I see that it uses ioperm and outb which seem to be Linux hardware IO commands. Is pretty much the only option for any type of port IO in Mac OS X limited to IOKit? If true, that seems like overkill for simple stuff. I am studying Computer Engineering so I have already done some basic Parallel port programming in Windows, but the thing I did was using a Win32 library specifically made for a certain board we were using. Any info would be appreciated. Edit: Oh and Keyspan has some sample code for accessing serial ports over USB. Maybe that's all I need? But can that be used with Parallel->USB adapters? Edit 2: I see this post which has some more info.