What Is Harvard Mark I?

In 1944, an awesome computer was born. It was called the Harvard Mark I, and it was a monster. It stood 55 feet long, eight feet high, and weighed five tons. Don't let its size fool you—this thing could do some serious math. During World War II (WWII), when it was first released, the Harvard Mark I provided vital calculations for the U.S. Navy that helped them win the war. If that wasn't impressive enough, this was also the first computer to have what we now know as "programming." So while it may not be first in line when it comes to being the world's first programmable computer—that honor goes to Konrad Zuse's Z3 model from 1941—it is still widely considered one of the essential computers ever built. This was a significant breakthrough in computing technology, but it was also very big—so big that it took up an entire room. It weighed around 5 tons and required two rooms to house it: one for the computer's inner workings and another for its operator. The operator used a teletypewriter keyboard to communicate with the machine, which could take up to 24 hours to process one instruction. Despite its size and complexity (it required six people to operate), the Mark I served as a template for future computers. It connected early theoretical work by Charles Babbage (1791–1871) and modern-day computers. The Mark I was a computer that was the first of its kind and was used to calculate rocket trajectories during World War II. Howard Aiken developed it at Harvard University. The Mark I remained in use at Harvard until 1959, when fully electronic computers already far surpassed its technology. Mark, I was followed by Mark II, Mark III and Mark IV.