Dual frequency oscillator on PS1. Perfect NTSC/PAL timings

% Leah Rowe % 2020-03-13

This applies to any PS1 that has the 208-pin GPU. For older SCPH-1xxx models there is a 2nd install point for adding a 2nd oscillator and you just then need to cut the relevant trace depending on your model.

I am selling these pre-modded on https://minifree.org/

Picture of motherboard is based on the one from: https://commons.wikimedia.org/wiki/File:Sony_Playstation_1_SCPH-7502_motherboard_top.jpg (CC-BY-SA 4.0 license)

Here’s how to do it!

Installation diagram:

NOTE: I recommend installing the oscillator above the RF shield (the one that the CD drive is mounted upon)

Example installation pics:

If the above diagram is confusing, then here are written instructions:

If PAL PS1, cut trace leading to pin 196 and (via 220ohm resistor) the output of a 53.69mhz oscillator goes to it.

If NTSC PS1, cut trace leading to pin 192 and (via 220ohm resistor) the output of a 53.2mhz oscillator goes to it.

PWR can be 3.3v. Larger 4-pin oscillators are typically used on 5V systems but can also be powered by 3.3v. An oscillator is just a crystal and some caps/transistors at the end of the day!

NOTE: An easier way to do DFO is to IGNORE this guide completely, and buy this kit instead: https://videogameperfection.com/products/dual-frequency-oscillator/ NOTE: If you use this kit, there is a PAL/NTSC pin on the video encoder which is the control pin. then you just remove the 220ohm resistor from the PS1 going into pins 192/196 and connect to pad.

Notes:

Remarks:

You need:

Download the source code for this page

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Workers of the world, unite! You have nothing to lose but your chains.
Workers of the world, unite! You have nothing to lose but your chains.
Workers of the world, unite! You have nothing to lose but your chains.
Workers of the world, unite! You have nothing to lose but your chains.
Workers of the world, unite! You have nothing to lose but your chains.
Workers of the world, unite! You have nothing to lose but your chains.
Workers of the world, unite! You have nothing to lose but your chains.
Workers of the world, unite! You have nothing to lose but your chains.
Workers of the world, unite! You have nothing to lose but your chains.
Workers of the world, unite! You have nothing to lose but your chains.
Workers of the world, unite! You have nothing to lose but your chains.