3 ms·
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 too
by kens 6y ago
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.
- tyingq 6y agoSupposedly that made it twice as fast at the same clock speed.
- tpmx 6y agoSomeone (not me!) edited https://en.wikipedia.org/wiki/NEC_V20 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."
- Arcorann 6y agoAccording 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 https://ja.wikipedia.org/wiki/NEC_Vシリーズ