The text was dynamically updated by Incredible Technologies as part of their network for the games. The display board apparently also served as a sort of "port multiplexer" - the modem was connected directly to it (heck, there were even provisions for the modem to be built into the board, but those spots were always depopped). There's a flash chip on the board (Intel, IIRC) that probably stores all the current data for the device to display.
There's a way to move a set of resistors around and make it boot off that flash chip, but then you'd need a way to program it. There's no JTAG interface or anything to bit bang the address/data bus, IIRC, so that may not be an easy task aside from a bootloader.
That and figuring out how to actually work the front panel part is about as far as I got reverse engineering those things before I got totally busy. I've had other things way higher up the priority list ever since. Heck, I've been working 45+ hour (billable, let alone the administrative time) weeks for the past month or so.