808x > AMDD8086
Modified: March 11, 2005, 10:44 pm
Manufacturer:AMD
Model:D8086
Speed:4.77MHz
Type:8086
Data Code:8351
Introduced:1978
Transistors:29,000
Package:40CDIP
Process:3 Micron
Architecture:16 bit x86
Used in:Computers, Terminals Etc
Description:.
Intel 8086 microprocessor is a first member of
x86 family of processors. Advertised as a "source-
code compatible" with Intel 8080 and Intel 8085
processors, the 8086 was not object code
compatible with them. The 8086 had complete 16-
bit architecture - 16-bit internal registers, 16-
bit data bus, and 20-bit address bus (1 MB of
physical memory). Because the processor had 16-
bit index registers and memory pointers, it could
effectively address only 64 KB of memory. To
address memory beyond 64 KB the Intel 8086 used
segment registers - these registers specified
where code, stack data and extra data 64 KB
segments are located within 1 MB of total
processor memory. To accommodate this awkward
memory addressing many 8086 compilers included 6
different memory models: tiny, small, compact,
medium, large and huge. 64 KB direct addressing
limitation went away with the introduction of the
32-bit protected mode in Intel 80386 processor.

AMD was a second source to IIntel, often
overtaking them in production.