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Guy Harris (talk | contribs) →Examples: Wireless network interface controllers *are* network interface controllers; listing both of them is redundant. |
→Moving up the line: removed dot before unfinished sentence, added cn for that part, note that the 68000 gates on the 68000 processor doesn't seem a joke, see https://en.wikipedia.org/wiki/Transistor_count#cite_note-29 + Motorola_68000 |
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The same basic evolution occurred with [[microprocessor]]s as well. Early designs were extremely simple, and even the more powerful 8-bit designs of the mid-1970s like the [[Zilog Z80]] had instruction sets that were simple enough to be implemented in dedicated logic. By this time, the control logic could be patterned into the same die as the CPU, making the difference in cost between ROM and logic less of an issue. However, it was not long before these companies were also facing the problem of introducing higher-performance designs but still wanting to offer [[backward compatibility]]. Among early examples of microcode in micros was the [[Intel 8086]].<ref name=microcode/>
Among the ultimate implementations of microcode in microprocessors is the [[Motorola 68000]]. This offered a highly [[orthogonal instruction set]] with a wide variety of [[addressing mode]]s, all implemented in microcode. This did not come without cost, according to early articles, about 20% of the chip's surface area (and thus cost) is the microcode system
===RISC enters===
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