serial number on frame

Can anyone tell where I can find a serial number on a 1990 S-10 frame?
I have been told on the drivers side right behind the motor mount? Also on the p***anger side frame rail right in front on the rear axle and also on the p***enger side right around the fire wall or under the door area. How many letter/numbers. Is it the same as the vin number.

Thanks

 

Need help guys

 

ask here

http://www.s10forum.com/forum/?

 

Stamped on the frame facing up. Right around the drivers door. Not a real clean stamp either. Need the body off to see it clearly.