PS1 disable dithering w/ Gameshark or Action Replay codes

I recently came across this post. Looks pretty cool to see dithering disabled with Action Replay codes. I wonder how involved it would be to find more codes to run on physical hardware? It reminded me of gameshark codes found for the N64 to disable AA.
Hacks below found by Chris Covell.
https://twitter.com/covell_chris/status/946046856064143360

 

wow cool!

 

How would one find the code for each game? I would love to give this a try on a few games not listed.

 

Well, the author of these codes gave these indications - maybe we could try to reverse his work to see what adresses have in commun :

@https://twitter.com/covell_chris/status/946047748180140032

 

I asked the question about disabling dithering 2 years ago and now its possible. great!
Esppiral should see this. He is the widescreen master! I would love to see Silent Hill on original hardware without dithering!

 

Yea I wondered about it for a while too since something similar has been done with N64 to remove AA. I just stumbled on it at random.

 

That's pretty neat,

Now those psx games look like Saturn games without dithering but showing banding instead.

I'd like to see the same done for the Dreamcast, very few titles actually run without dithering on the Dreamcast, and they look impressively clean compared to the ones that use it.

 

Humm, weird.

I tried to reverse the process of what Chris Covell did in 2 games, to determine which value he replaced by 0000 (in Crash Bandicoot 2 and Ridge Racer).

In Ridge Racer NTSC-J, at adress 00AD1B08 in Cheat Engine (80046468 - 7F574960), original value is 0200.
In Crash Bandicoot 2 NTSC-J, at adress 00ADA514 in Cheat Engine (8004EE74 - 7F574960), original value is also 0200.

Unfortunately, when I replaced 0200 by 0000 in Cheat Engine, nothing happened. :/

But I noticed 1 thing :

Ridge Racer :



Crash Bandicoot 2 :



Look how values before and after 0200 are (almost all) the same in these 2 games. Why ?

 

Silent hill without dithering looks super bad

 

Hmm on emulator with original resultion, dithering disabled and scanlines it looks IMO good .

 

Someone with a twitter account can ask Chris Covell on his twitter page. He has a main website but I don't see anything PS1 related.
http://www.chrismcovell.com/index2.html

 

I do wonder how good games like Metal Gear Solid, Resident Evil, Alone in the Dark would look like without Dithering. I would assume it would look as good as the Dreamcast ports with the exception of it being 240p instead of 480p like on Dreamcast.

 

chris will create a guide for us

https://twitter.com/braschka12345/status/957582122818076672

 

Awesome!

 

Very cool. I can see this being a game by game preference though. I haven't spent much time on PSX over the years and had no idea how present dithering is.

 

Is anyone else interested in using Gameshark codes to run on real hardware with original discs or just HEX patches?
Just wondering. I've been using Gameshark Module that connects to the back of the I/O port to run games in widescreen. Same thing with the N64 to disable AA and run games in widescreen.

 

I wasn't even aware of dithering on 2D primitives, since they aren't supposed to use any shading by default. I mean, the only instance of dithering should be present on semi-transparent sprites and if you explicitly add a MODE primitive to the draw chain, at least from what I can recall specs.

 

Sorry to post it here, but may this info help to achieve the same on the Dreamcast?

http://mc.pp.se/dc/pvr.html



31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
TH D COL
The pixel format of the frame buffer to which rendering is to take place.
TH - Alpha threshold
Set this to control the alpha threshold level when output colour mode is ARGB1555.
D - Dither enable
Setting this bit enables dithering in highcolour modes.
COL - Colour mode select
Selects the frame buffer pixel colour mode (all colour modes are little endian, e.g. in RGB888 the blue byte comes first)
Value Colour mode Bytes per pixel
0 0 0 RGB555 2
0 0 1 RGB565 2
0 1 0 ARGB4444 2
0 1 1 ARGB1555 2
1 0 1 RGB888 4
1 1 0 ARGB888 4

 

Sharing a new thread that has been started by ShaolinAssassin over at pcsx2 forums to remove dithering on PS1 games. There is a few posts on the widescreen thread where user Flatout shared some good info on what values to look for.
https://forums.pcsx2.net/Thread-PSOne-Dithering-OFF-patches
https://forums.pcsx2.net/Thread-PSOne-Widescreen-Patches?page=83

 

Tested with Crash Bandcoot. I guess there is small mistake in the code: 800041394 0000 The correct one is: 80041394 0000
It looks IMO better. Less pixelated when in motion. For people who like to keep a short distance to their TVs will see the most significant difference. The only downside is the shading on non-textured objects which looks rougher. I would love to see game like Silent Hill, RR4, Gran Turismo wtc. without dithering.
Here some screenshot. I have tested it via OSSC using scanline and without. The combination with scanlines and no dithering is a great one.

https://img3.picload.org/image/ddppiwor/c2.jpg
https://img3.picload.org/image/ddppiwaw/c1.jpg
https://img3.picload.org/image/ddppiwol/c3.jpg