ps1mods.md 5.1 KB

% My super modified Sony PlayStation 1 with MM3 modchip and enhanced audio/video % Leah Rowe % 23 June 2019

I am a sucker for retro videogames. You may recall from my How I do my computing article that I mentioned I own a PlayStation. I've recently replaced the one mentioned in that article with an original SCPH-1002 (PU-8) revision, and I felt like sharing pictures of all the mods that I've done to it.

UPDATE: I re-did this mod and improved the efficiency of the modchip wiring. See: better_ps1mods.md

A description is below of the mods that I've done. Followed by this are actual photos.

There is also a video, which you can see here:

Your browser doesn't support HTML5 video. Here is a link to the video instead.

Alternatively, a direct link to the video is as follows: https://av.vimuser.org/ps1mods/ps1mods.webm

If you have an old gaming system that you would like me to mod, send me an email :) I love any excuse to sit in my lab and tinker with electronics, and I thoroughly enjoy the work!

I have performed the following mods to this system (an SCPH-1002 model, with the high-quality audio DAC and the separate RCA phono jacks for audio):

  • Installed a MultiMode3 stealth modchip. This enables to boot CD-R backups and games from any geographical region, thus bypassing the DRM that is otherwise present on an unmodified playstation.
  • Cut the trace for pin 6 on the multi-out, which handles Composite Video, and connected it directly to a proper Composite Sync signal pulled from the GPU directly (pin 156) and filtered with a 470 ohm resistor and 220uF 4V capacitor in series. The result of this is vastly improved picture quality when using RGB sync, because now there is a proper Composite Sync signal; an unmodified playstation will simply use Composite Video as sync, which creates a distortion on the output
  • Cut the trace for audio on the multi-out. The multi-out now only outputs video signals
  • Cut the trace for audio on the RCA phono jacks
  • Re-directed (via jumper wires) audio that was going to the multi-out, to the RCA phono jacks. This results in better quality audio because it's now separated from the video lines, meaning there is less interference on the audio. The RCA jacks on an unmodified SCPH-100x playstation are usually very noisy with a lot of interference from nearby components, and the audio on the multi-out is better quality but still affected by interference from the video lines. Thus, this mod does away with both problems and creates the best possible audio quality (with the exception that it is possible on a few later playstations to add a Toslink output for digital audio. However, I don't have a setup capable of using Toslink)
  • Replaced the default green LED with a red one, also replaced the resistor with the correct size (75 ohm) and connected it to the power rail for the laser sled instead of directly to the PSU. This results in a blinking red LED on disc activity, or whatever the laser moves position, due to fluctuating power output when this happens. The LED is connected in parallel so as not to affect the operation of the CD drive (from which the power rail is able to provide plenty more current draw than the CD drive actually needs, thus making the LED mod feasible)
  • Professionally calibrated the laser assembly so as to read discs again like new, as if it were just out of the factory. Most of these laser units work fine but need some tweaking nowadays when you buy these old consoles

I really just wanted to show off my work. In addition to the above video, here are pictures:

Composite Sync mod, for proper RGBS output:

Mod for enhanced audio quality:

Mod-chip installation (7-wire MultiMode3 stealth):

Replacement LED (red colour. Resistor is underneath the board):

One more shot of the mod chip, for good measure!

Laser assembly power rail connected to LED via detachable jumper wire (male+female):

System has been re-assembled and its ready to go!

I had a lot of fun building this! I'm soon going to be creating a whole new company (on a new website. it won't be done through minifree.org) selling these systems pre-modded similarly to the above.