BTO I worked for part time summers in high school planted corn with a 494 planter, 4-38 inch rows, beans he planted 6-30's with a Deere 690. To be best of my knowledge Deere never made a 690, his was made from two 490's with some parts left over.
Dad got a brand new 490 spring of '52. One of the first 4-row planters in the neighborhood. It was getting pretty worn out by 1972 when Dad quit farming. The old runner style planters were a real PITA to set depth with. I remember the last field of beans we planted spring of '72. 20 acres, had been fall plowed, worked up like a sandbox, Dad always only made 2 rounds of endrows, took 3+ hours he stopped and adjusted planter so much to keep planter from burying the seed. Should have been able to plant the whole field in not much more time than that! If a clay sidehill was damp when disked, cloddy, planter would drop seed on top of ground. Planter had two sets of Gandy boxes, insecticide and herbicide. Used only one set most times. Always hill dropped corn, group of 3-4 seeds every 25-30 inches. Beans were drilled, one or two every 8-10 inches.
Today's planters are beastly expensive for what they are, but their ability to plant no-till, hold seed depth, even spacing between plants, and allow planting up to 7-8 mph or more is amazing. These 50-60 year old planters need to be in a museum, not trying to plant a crop today.