1) prepare a critical note on the drive system used with machine tools. Specify their relative merits and demerits. describe the coordinate systems of NC machine tools with a neat sketch. describe the construction and the operating steps of automatic tool changer. a) prepare a note on slide positioning system. b) describe the principle of optical grating. prepare a critical note on principle of working of pneumatic, hydraulic and electro-mechanical systems for position control. a) prepare a note on punched tape. b) prepare a note on NC part programming. prepare a critical note on compute automated part programming.