As far as Splatterhouse is concerned, there is also a chainsaw in Splatterhouse 2. Unlike part 1, where the only chainsaws were attached to Biggy Man, Rick can use the chainsaw against the third boss. Unfortunately, that's the only place in the game it can be found.

And I have to ask... were there any older Evil Dead games? I don't recall seeing any (except for a bad Zelda II ROM hack) prior to Evil Dead: Hail to the King (PSX, DC, PC - and yes, the chainsaw was present in it). Then again, maybe there was a PC game or something prior to that that I never saw.