Somewhere around 40, starting in mid-1980s with Koala MacVision digitizer connected to Macintosh 512K desktop computer (1-bit output!)
I bought and resold a lot of small-sensor cameras because I was bored and hoped to find one with a nice gritty, mid-fi look. But this was mostly wasted effort, as the majority of them applied noise reduction with a heavy hand and/or suffered from ugly sensor artifacts. Ricoh GX100 was one of the better ones. But as I later discovered, half-frame 35 mm film cameras loaded with high speed film also deliver the goods.
In recent years, my buying has slowed to a trickle (trying to avoid boredom-buying), and most of it has been Sony: Not very gritty/mid-fi, but useful. Really am surprised that the cameras which I've kept the longest should come from a company known for producing motion pictures, radios, robotic dogs and game consoles, but so it goes.