Given that computers are made up of transistors and diodes a binary system is inevitable. This is because either the transistor gets voltage and is switched to On, or it doesn't get voltage and is therefore stuck on Off. Now, this binary system will have to give way when quantum computers come in if scientists at Santa Barbara university have anything to do wit progress. They say that a five state system would enable staggeringly powerful computers.
They are positive that a trinary system would enable three position switches, and a single 'trit' could hold far more information than today's 'bits'. This groups have already built a computer with five basic states. Ask this question in two years time!
Computers most certainly do still use the binary system. A good example of this is with cell phones. Cell phones are known exclusively to use the binary system to program their computer systems. Home computers use the binary system in the same that it has been used for computers since the beginning of computers. A computer saves and retrieves data with a system of numbers that is better known as the binary system. It uses a string of numbers in order to process commands and complete functions. It is officially known as the base-2 numeral system and has been used in digital circuitry for a very long time. The binary number code system can actually trace its roots back to 16th and 17th century Europe. It is believed that some form of binary number code was present during the days of acient China and the days of Biblical lore in Egypt.