Instead the Mark I was constructed out of switches, relays, rotating shafts, and clutches. But it was not a purely electronic computer. This was the first programmable digital computer made in the U.S. Mark I computer which was built as a partnership between Harvard and IBM in 1944. it was the first operating machine that could execute long computations automatically.
Mark I is the first machine to successfully perform a long services of arithmetic and logical operation. Mark I : The IBM Automatic Sequence Controlled Calculator (ASCC), called the Mark I by Harvard University, was an electro-mechanical computer. Some of the computers of this generation were: These computers were large in size and writing programs on them was difficult. The Vacuum tube was developed by Lee DeForest in 1908.
They stored information in the form of propagating sound waves. The high cost of vacuum tubes prevented their use for main memory. the first ‘computer’ to use electronic valves (ie. The digital computes using electronic valves (Vacuum tubes) are known as first generation computers.