Then, a new option came along. How about using a Raspberry Pi as the computer to drive the printer? That way I'd free up the laptop for everything else. I already have a monitor that I can re-purpose, I also have a keyboard and mouse collecting dust. So I ordered the Raspberry Pi starter kit from amazon for under $70. I did add an HDMI - DVI cable adpter for $8 since the Dell monitor has a DVI port rather than HDMI.
I can't believe how easy this was to set up. The Raspberry Pi came with NOOBS preloaded on the micro SD and a wireless usb NIC. I plugged everything in, ran through the setup and booted to the desktop. I entered my network password in the network config tool and had internet connectivity in under a minute. At www.RepRap.org, I found instructions to install my Pronterface on a Debian Linux box. The system threw an error when I ran this command sudo echo "deb http://apt.ulrichard.ch/ squeeze main contrib non-free" >> /etc/apt/sources.list and I had to hack around a bit to figure out how to edit the \etc\apt\sources.list file. After un-commenting out the line in there, I got the Pronterface files to download and install.
I started up the program, plugged in my Airwolf3d v5.5, set the baud rate to 250000, and low and behold, it connected. I sent a few test commands, and the printer moved correctly. I preheated the hot end to 240, everything was working as it should. I copied a calibration file from my laptop onto a usb memory stick and plugged it into the last open port on my Raspberry Pi. Pronterface recognized the mounted drive and I was able to load the gcode file and print it.
I thought it was going to take me a week or two to get this to work. It took less than 4 hours. Now I can run all three of my printers without worrying if I'm going to inadvertently kill a print job in the Airwolf3d