Well, unfortunately I found a board that this mod *doesn’t* work for. I bought a Micronics (Micron) M54Li since it would be able to cache more than 64MB of RAM — and my modded Tilamook locks up if L2 is enabled. I even tried adding split rail detect mod even though the CPU already booted without it.

So, this isn’t a silver bullet. There are apparently motherboards that you still can’t enable L2 on…

aspiringnobody wrote on 2025-10-17, 14:57:

I bought a Micronics (Micron) M54Li

This is a really very old generation of a socket 5 mainboard, being on the market at the same time with the earlier socket 4 for the first generation of Intel Pentium.
Even it is equipped with a SiS-chipset, it will have probably big problems to work with this last Tilamook-generation of a Pentium 1.
Aside from that, this board does not offer dual-voltage (Vcore and V I/O) for any MMX-CPU, so how did you solve this problem?

aspiringnobody wrote on 2025-10-17, 14:57:

Well, unfortunately I found a board that this mod *doesn’t* work for. I bought a Micronics (Micron) M54Li since it would be able to cache more than 64MB of RAM — and my modded Tilamook locks up if L2 is enabled. I even tried adding split rail detect mod even though the CPU already booted without it.

So, this isn’t a silver bullet. There are apparently motherboards that you still can’t enable L2 on…

Yes, I just discovered this with my Lucky Star 5VP3. I wonder if there's yet another mod that needs to be done. It seems to not like this VIA chipset, since L2 worked on a 430HX board.

Wow, these Tillamooks have become too expensive for the mere curiosity value they have. I have a 166mmx with a semi-unlocked multiplier that does 3.5x83 easily. Wonder if a BF0 bridge would have the same result as on a Tillamook chip?

Mine were able to reach stable frequencies over 400MHz. 100MHz external clock was no problem, only multiplier was the limiting factor.
These are the absolute pinacle of Pentium MMX. So if you want to go P55C, these are the way.