There used to be an entire forum here dedicated to the "homebrew" community. After a LOT of work, it started fracturing off into other forums (jesse's hunting page, hagshouse, and some that i forget) . Its about that time that some individuals started building their own boards for use in the homebrew cams (BG2, snapshot sniper, etc). The first affordable "commercial" cameras that i remember, had the same camera's that we were using (samsung, sony, etc) but they had their own boards, but they could manufacture a lot cheaper thus the cheaper prices.
When we moved out here to CO and i had to clean out my attic, i found a couple of sony film cams and some of those walmart motion sensors, no less than 15 or so completed trail cams (film) , and 4 or 5 digital homebrew trailcams. I kept a few working ones just for nostalgia .