> People often ask if microcode could be updated on the 8086. Microcode was hardcoded into the ROM, so it could not be changed. This became a big problem for Intel with the famous Pentium floating-point division bug. The Pentium chip turned out to have a bug that resulted in rare but serious errors when dividing.
Do we really know whether fixing the Pentium FDIV bug would have actually been in the reach of microcode patching capabilities? Based on googling the FDIV bug is due to errors in some sort of PLA which presumably couldn't have been patched.
The Pentium FDIV algorithm could have been changed in microcode Newton-Raphelson to sidestep the issue. Depends on exactly what resources they would have in microcode.
Do we really know whether fixing the Pentium FDIV bug would have actually been in the reach of microcode patching capabilities? Based on googling the FDIV bug is due to errors in some sort of PLA which presumably couldn't have been patched.