The Intel 8085 (“eighty-eighty-five“) is an 8-bit microprocessor introduced by Intel in 1977. It was binary compatible with the more-famous Intel 8080but 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 requires only a +5-Volt (V) power supply rather than the +5 V, −5 V and +12 V supplies the 8080 needed. Both processors were sometimes used in computers running the CP/M operating system.

The Intel 8085 required at least an external ROM and RAM and an 8 bit address latch (both latches combined in the Intel 8755 2Kx8 EPROM / 2×8 I/O, Intel 8155 256-byte RAM and 22 I/O and 14 bit programmable Timer/Counter) so cannot technically be called a microcontroller.

Both designs (8080/8085) were eclipsed for desktop computers by the compatible Zilog Z80, which took over most of the CP/M computer market as well as taking a share of the booming home computer market in the early-to-mid-1980s.

The 8085 had a long life as a controller. Once designed into such products as the DECtape controller and the VT100 video terminal in the late 1970s, it served for new production throughout the life span of those products (generally longer than the product life of desktop computers).

Intel 8085A CPU Die

Pro-Log Corp. put the 8085 and supporting hardware on an STD Bus format card containing CPU, RAM, sockets for ROM/EPROM, I/O and external bus interfaces. The included Instruction Set Reference Card used entirely different mnemonics for the Intel 8085 CPU, as the product was a direct competitor to Intel’s Multibus card offerings (wikipedia)



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