Safety Guy Butts in . . .
Aside from those historical models posted, all (?) modern chainsaws are designed to be used 'right handed'. That is, the right hand on the rear handle, and the left hand on the top handle.
This info is posted in all of the owner's / user's manuals / safety guides, etc.
Why? A couple of examples.
1) In a kick-back situation, when bucking/crosscutting a horizontal log, a chainsaw held right handed will pass by the right side of your head (if correctly held, sightly to the right, and with a locked left elbow). A chainsaw held left handed will kick back right toward your face or into your right forearm.
2) The 'kill switch' for most modern saws is located to be operated with the right thumb. Holding the saw 'lefty' makes this harder to reach while maintaining a secure grip on the rear handle.
3) Harder to reach the trigger while maintaining a secure grip on the rear handle when felling.
This doesn't mean you can't get away with it sometimes, but it should not be a regular practice.
I once found one of those consumer education pamphlets at Lowe's that said you could use a chainsaw either right or left handed, and sent them copies of the owner's manuals from the Husky saws they were selling, that said 'right hand only'. Lowes' pulled the brochures but never even acknowledged my letter.
Philbert