J-Comp
Flatwater Electronics Main page
The J-Comp loom control is entirely external, with it's own power supply, and connects to the loom with the original computer cable.  Connection to the computer is with an integral USB cable.  Just plug it in, turn it on, connect your computer and weave.  

In addition, there are visual indicators showing both loom operation and communications between the loom control and the computer.  These indicators help to identify whether problems are with the loom or the computer.

The J-Comp loom control uses the Macomber Loom Driver.   I recommend using Fiberworks weaving software.  However any weaving software that has the Macomber loom driver will run the loom.
Fiberworks
The USB connection uses the FTDI USB to Serial.  With the latest versions of Windows and starting with Mac OS X 10 the Converter is "plug and play" as the USB drivers are included in those operating systems.  

For older systems, such as Windows XP or Mac OS X 9 and earlier, a driver may be downloaded to your PC and installation is straightforward.