Complex sentence: To be useful for business applications the computer had to be able to handle a number of data streams, input and output, simultaneously and its chief designer, Dr. John Pinkerton, therefore designed the machine to have multiple input/output buffers.
Split into simpler sentences: To be useful for business applications, the computer had to be able to handle a number of data streams, input and output, simultaneously. Therefore, its chief designer, Dr. John Pinkerton, designed the machine to have multiple input/output buffers.