The multi output frequency oscillator (MOFO) is a dual clock mod for the Sony PlayStation that provides a switchable PAL/NTSC GPU clock and PAL/NTSC RGB Encoder subcarrier clock, as well as a fixed subcarrier clock for PAL60 operation.

What is the difference between a DFO, MFO, and MOFO?

• The Dual Frequency Oscillator (DFO) provides an auto switching GPU clock output.
• The Multi Frequency Oscillator (MFO) provides an auto switching GPU clock output and an auto switching subcarrier clock output.
• The Multi Output Frequency Oscillator (MOFO) provides an auto switching GPU clock output, an auto switching subcarrier clock output, and an additional fixed subcarrier clock output.

The MOFO is an updated version of the MFO which itself was an updated version of the DFO.

Compatibility

PU-8 / PU-18

• GPU output is necessary for correct GPU clock in 50Hz and 60Hz console modes.
• Sub-A output is not necessary because the GPU creates the correct PAL & NTSC subcarrier clocks in all regions.
• Sub-B output can be used to force PAL60 operation for use with TVs that are incompatible with NTSC signals.

PU-20 / PU-22 / PU-23 / PM-41

• GPU output is necessary for correct GPU clock in 50Hz and 60Hz console modes.
• Sub-A output is necessary to get correct PAL & NTSC subcarrier clocks in all regions.
• Sub-B output can be used to force PAL60 operation for use with TVs that are incompatible with NTSC signals.

Recommended Dual Clock Mod

PU-8 / PU-18

• If using RGB = DFO (or MOFO using GPU clock output only)
• If using composite video & a dual format PAL/NTSC TV = DFO (or MOFO using GPU clock output only)
• If using composite video & a single format TV = MOFO (GPU clock output & Sub-B clock output)

PU-20 / PU-22 / PU-23 / PM-41

• If using RGB = DFO (or MOFO using GPU clock output only)
• If using composite video & a dual format PAL/NTSC TV = MOFO (GPU clock output & Sub-A clock output)
• If using composite video & a single format TV = MOFO (GPU clock output & Sub-B clock output)

Manufacturing

Nothing special. 1mm PCB is fine.

Version History

• MOFO v1 - 06/05/2023