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Notes on the Pentium's microcode circuitry

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180 points leotravis10 | 2 comments | 3/31/2025, 6:35:00 PM | HN request time: 0.421s | source
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kens ◴[3/31/2025, 6:51:00 PM] No.43538380[source]▶

Author here for your Pentium questions :-)

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dreamcompiler ◴[4/1/2025, 4:20:00 AM] No.43542817[source]▶

Isn't the Pentium's microcode upgradable? Or is that only in later chips?

These fixed transistors imply no upgradability.

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1. kens ◴[4/1/2025, 5:23:00 AM] No.43543118[source]▶

Microcode updates were first implemented in the Pentium Pro. When the original Pentium had the infamous FDIV bug, the only fix was for Intel to replace the processors at a cost of $475 million.

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2. sroussey ◴[4/1/2025, 5:57:00 AM] No.43543303[source]▶

Good thing win95 came out soon after and filled everyone’s coffers from new equipment buying