Hi all,

I have a Tulip TC42 system with a PCA TC42B13 motherboard (OEM Tulip desktop, Socket 5/7 era) running a Pentium 75 MHz CPU.

BIOS is PhoenixBIOS 4.03.

I would like to upgrade to a Pentium 133 MHz, but I cannot find any documentation about the jumper or DIP-switch settings for CPU frequency.

Current situation:

Tulip TC42 (PCA TC42B13 motherboard)
PhoenixBIOS 4.03
CPU option in BIOS only shows “CPU Speed: Full Speed” (no selectable values)
No clear CPU speed jumpers visible on motherboard (only ISA/PCI riser present)
System currently runs stable at 75 MHz (50 MHz FSB × 1.5)

What I am trying to achieve:

Set system to 133 MHz (likely 66 MHz FSB × 2 multiplier)

Question:
Does anyone know the exact jumper or DIP-switch settings on this board (or CPU riser if applicable) to switch from 75 MHz to 133 MHz?
Or does this board automatically switch FSB based on CPU, meaning a Pentium 133 would just work without changes?

Any manuals, photos, or service docs would be highly appreciated.

Thanks!