Apparatus for forming holes in sheets of material at precise locations therein in relation to first and second marking means on each sheet at two respective locations therein, said apparatus comprising lockably adjustable receiver means for receiving sheets one by one and for holding said sheets in fixed position, operating means operatively positionable in determined location relative to said receiving means for forming holes in said sheets at precise locations therein, movable optical means for viewing each sheet to detect said first and second marking means respectively at said two locations thereon, display means operatively associated with said optical means for simultaneously visually displaying images of said first and second marking means, index positioning means on said display means, means for moving said optical means relative to said receiver means to establish correspondence between said index positioning means on said display means and the images of said first and second marking means, means for locking said optical means relative to said receiver means to establish a fixed relation between said index positioning means and said operating means, and means for adjustably moving said receiver means with said optical means fixed relative thereto to align the images of said first and second marking means on another sheet, as viewed on the display means, with the index positioning means thereon, said operating means being operated to form holes in each sheet of material when the images of said first and second marking means on the sheet are substantially aligned with the index positioning means as viewed on said display means.