80186 is often forgotten to have existed because it didn't see much success in the market / because IBM skipped it and went with 80286 for the AT, but it did exist.
The 80186 didn’t really introduce anything new architecturally. It’s basically an 8086 with a few more chips bundled on-die. 80286 however introduced protected mode, expanded the address size to 24 bit, hardware enforce memory protection, multitasking, etc.
Four because you have to count 8086 itself (486 was one, not zero, geverations before the Pentium and so on).
80186 is often forgotten to have existed because it didn't see much success in the market / because IBM skipped it and went with 80286 for the AT, but it did exist.
The 80186 didn’t really introduce anything new architecturally. It’s basically an 8086 with a few more chips bundled on-die. 80286 however introduced protected mode, expanded the address size to 24 bit, hardware enforce memory protection, multitasking, etc.
I believe 80186 was for embedded systems.