Back to my Ohio Scientific Challenger 1P

Vintage Computer Buds, I dug out some cables and hooked up my Challenger 1P to my TV. Instead of hooking the video directly to the TV like I did before, I hooked it through a Magnavox Modulator that rebroadcasted the video signal on channel three. This worked for some reason. Well, kind of. The URL is to a photo of what displayed on the TV. It wasn't too easy to read, but it is clearly some kind of ASCII character dump. No clue what's going on. Do I need to invest in a proper old-style modulator like they used on the Atari 2600 that will "split" the A/V signal from a single RCA cable and then put it on channel 3? Per the website, [ http://www.old-computers.com/museum/computer.asp?st=1&c=813 ] that looks to be the case... Here's the output I do have. What the heck is my machine doing? http://imgur.com/UWcZ8 -- -Jon Jonathan Katz, Indianapolis, IN.