It has been a while since I have see one. They were/are mounted on the tractor front, with a flat belt drive. A cradle held the log, and tipped, or rocked the log into the saw blade. The blade is large. I'm not sure, but 24" diameter?
As noted, they cut logs, and hands, and arms with no discrimation.
As hazardous as a chain saw can be,the chain saw can't hold a candle to the buzz saws.
They may be someone with better information, that's my take.
