The
Jam!! has one function: it allows the PlayStation to be connected to an SVGA monitor (while allowing PC video to pass through when not in use). Why would this be useful? Well, there are a few instances which spring to mind. First, it is generally more acceptable for a person to ?hog? a computer than the TV. If you are going to be in front of the computer anyway, who cares if you are playing PSX. Second, although TVs are usually, on average, larger than PC monitors, they are not as crisp or accurate, and are typically older. In addition, TV sound systems are usually not as well suited for games as PC sound systems, which were designed with gaming in mind.
This actually would be a fairly weak argument if it weren?t for the fact that the Jam!! takes its video signal from the PSX in the S-Video format. This provides a picture which is much more vibrant and sharp than the video signal most PSX games are using on their TVs. So, the final word on Functionality is this -- If you do have an old TV and have a nice-sized monitor (or plan to upgrade your monitor before your TV), then you should consider picking up a Jam!!