Intel 8085

The Intel 8085 is an 8-bit microprocessor made by Intel in the mid-1970s. It was binary compatible with the more-famous Intel 8080 but required less supporting hardware, thus allowing simpler and less expensive microcomputer systems to be built.

The "5" in the model number came from the fact that the 8085 required only a 5-volt power supply rather than the 5V and 12V supplies the 8080 needed. Both processors were sometimes used in computers running the CP/M operating system, and the 8085 later saw use as a microcontroller (much by virtue of its component count reducing feature). Both designs were later eclipsed by the compatible but more capable Zilog Z80, which took over most of the CP/M computer market as well as taking a large share of the booming home computer market in the early-to-mid-1980s.

The 8085 can access 65,536 individual memory locations, but can only access one at a time, because it is an eight bit microprocessor and each operation requires eight bits to preform it. Unlike some other microprocessors of its era, it has a seperate address space for up to 256 I/O ports. It also has a built in register array which are usually labeled A,B,C,D,E,H and L. The microprocessor also has three hardware based HALT operations which are found in pin 7 pin 8 and pin 9, these are called respectfully RST 7.5, RST 6.5, RST 5.5. RST 7.5 is used in case of a power surge.

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