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Comment by kens | Hacker News Reader

Yes, I've been working through different parts of the 8086 lately. My goal is to understand the microcode. I hope people aren't getting tired of the 8086 :-)

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> I hope people aren't getting tired of the 8086 :-)

On the contrary! These posts are fascinating and captivating!

Maybe the NEC V33 would be interesting to compare. 8086 compatible, but all done with regular logic, no microcode.

I'm surprised that NEC would do away with the microcode, since there is a lot of microcode in the 8086. It would be interesting to see how much circuitry it took to replace the microcode.

According to the Japanese Wikipedia page [1] it was actually in response to a lawsuit about V30 breaching the copyright of 8086 microcode. The extra speed would just be a bonus.

[1] https://ja.wikipedia.org/wiki/NEC_Vシリーズ

Supposedly that made it twice as fast at the same clock speed.

Someone (not me!) edited

https://en.wikipedia.org/wiki/NEC_V20

to say

"The NEC V33 is a super version of the V30 that separates address bus and data bus, and executes all instructions with wired logic instead of micro-codes, making it twice as fast as a V30 for the same clock frequency. V33 has the performance equivalent to Intel 80286. NEC V33 offers a method to expanding the memory address space to 16M bytes. It has two additional instructions BRKXA and RETXA to support extended addressing mode. The 8080 emulation mode was not supported."

That's pretty interesting. How does the transistor count compare?

No, quite the opposite. I look forward to reading your news posts. And this is generally how I find out about them. Please keep up the great work.

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