Objective: In the last lecture we discussed the importance of binary numbers in the representation of numbers, letters, mathematical symbols, voice, and pictures. Since all these phenomenon can be represented by strings of binary numbers, a single computer-communication system can manipulate all of them. We do not need separate systems for each. Total integration is about 30 years in the future. This lecture covers the current technology for manipulating the strings of binary numbers, which is referred to as microelectronics. Future manipulation of strings of binary numbers may be based on light circuits.