8086
The 8086, introduced in 1978, is still the compatibility basis for all Macs and PCs today. A little later, Motorola’s 680×0 appeared, also one of the most successful chips of all time.
The Intel 8086 is a 16-bit microprocessor from Intel. Developed in 1978, it became the forefather of the 80×86 family. The design was based on Intel’s 8-bit CPUs 8080 and 8085, the instruction set was designed so that assembly source code for the 8080/8085 could easily be automatically converted into valid 8086 source code. However, there was no direct compatibility, i.e. the possibility of running the 8080 programs without reassembly. Like the 8080, the 8086 lacked some essential components such as interrupt and DMA controllers, which were added as external chips. The 8086 also does not support floating point operations, but can natively work with an Intel 8087 coprocessor, which then performs the floating point calculations. The Intel 8089 coprocessor offers extended I/O functions and serves, among other things, as a DMA controller. Version 8088 was later released with an external command and data bus reduced to 8 bits.
