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Three - after 8086 you had 80286, 80386, 80486 and then Pentium (superscalar).
by vlovich123 4d ago
Three - after 8086 you had 80286, 80386, 80486 and then Pentium (superscalar).
- dpq 4d ago80186 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.
- vlovich123 4d agoThe 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.
- pkaye 4d agoI believe 80186 was for embedded systems.
- librasteve 3d agonope
- hyperman1 3d ago80186 Was not IBM PC compatible. It had e.g. a PIC, DMA and timer built-in, and these were incompatible with the chips in a 8086 based IBM PC. There were a few new instructions, too, mostly closing holes. You could left or right shift with a constant, while the 8086 had only 1 or the CX register. I think mul also gained a constant. The fact that Intel released a CPU that could not be put in a PC probably indicates how low they estimated the survivability of the PC.
- icedchai 3d agoThere were "PC compatibles" that used it, like the Tandy 2000. You are correct in that they may not have been entirely compatible, but they did exist.
- Sharlin 4d agoFour because you have to count 8086 itself (486 was one, not zero, geverations before the Pentium and so on).