Dissecting Sega Saturn Doom

[Dark Pulse]

21 minutes ago, Whiteysnakey said:

Thanks for having a look. :) It was looking at what happens on the PS1 version when you enable Nightmare that initially got me curious, Most likely looking in the wrong place.

You are, and I told you this over Discord...

 

The string is just a garbage string, basically. Nightmare as a proper selection was removed - so they removed the associated text. In its place became the password character set. The string is useless. Do not search by the string.

 

I'll repeat what I said there as well: You are looking for an address that has a value of 0 at "I am a wimp," 1 at "Not too rough," 2 at "Hurt me plenty", and 3 at "Ultra-Violence." Check the whole RAM, set the difficulty to IAAW, filter for 0, set the difficulty to NTR, filter for 1, etc.

 

When you can find one that confirms to all four of those values when you have that option set in the main menu, change the value of that address to 4. That will become Nightmare difficulty - if it exists.

 

If you find no results, it either doesn't exist, or it's doing things differently from how difficulty select worked in PS1 - which is unlikely, considering it's a port of PS1.

Edited August 3, 2022 by Dark Pulse

[Vic]

https://segaxtreme.net/threads/action-replay-codes-for-nightmare-difficulty-in-saturn-doom.25268/#post-182986

[Dark Pulse]

4 hours ago, Vic said:

https://segaxtreme.net/threads/action-replay-codes-for-nightmare-difficulty-in-saturn-doom.25268/#post-182986

Excellent work by that guy. There you go, WhiteySnakey - mystery solved.

[fafling]

Thank you !

Do you know why @Whiteysnakey deleted his messages ? He also disappeared from Kronos Discord after discussing about the possibility of the nightmare mode in Saturn Doom.

[Dark Pulse]

2 hours ago, fafling said:

Thank you !

Do you know why @Whiteysnakey deleted his messages ? He also disappeared from Kronos Discord after discussing about the possibility of the nightmare mode in Saturn Doom.

Probably because he was thinking that searching for the string would unlock Nightmare, and I was trying to tell him he was barking up the wrong tree and that searching for the string was a false flag. As you and I both know, the string actually has nothing to do with what Nightmare mode "is."

 

What he was basically looking for is what you found - the address that held the RAM value for "selected difficulty," which is what I was trying to point him to.

 

That said, the extra codes you did to make it more fully work and not completely wig out are very impressive stuff. :)

 

And yes, the game should be totally completable in Nightmare mode. Monster placements are the same as Ultra-Violence (that's standard Doom behavior), the fast reaction times and fast projectiles are all there, and all that's missing is enemy respawns (probably for RAM reasons, is my guess). That's all identical to PS1 Doom, which Saturn Doom is basically a port of (it wasn't supposed to be, but it's a long story; not sure if you want to hear it or are familiar with it).

Edited August 10, 2022 by Dark Pulse

[fafling]

Yes I know about the story of the Saturn port.

It's sheer luck that the code for the nightmare mode was left in place instead of being cleaned off.

[Dark Pulse]

1 hour ago, fafling said:

Yes I know about the story of the Saturn port.

It's sheer luck that the code for the nightmare mode was left in place instead of being cleaned off.

Since it's pretty much a straight port (right down to lumps like LIGHTS being left in the WADs even though the Saturn doesn't use that renderer at all), I figured there was at least a good shot of it being present :P

[ludicrous_peridot]

Just now, fafling said:

Yes I know about the story of the Saturn port.

 It's sheer luck that the code for the nightmare mode was left in place instead of being cleaned off.

My guess would be they (Rage) didn't have much time (or even a "mandate" - who knows)  for cleaning things up :)

[Dark Pulse]

3 hours ago, ludicrous_peridot said:

My guess would be they (Rage) didn't have much time (or even a "mandate" - who knows)  for cleaning things up :)

It was definitely time.

 

After Carmack shot down Jim Bagley's original renderer and mandated that it had to use the original renderer, there was pretty much next to no time left before the game needed to be mastered, so Bagley quick-and-dirty ported the PSX version. He didn't have time to sift through the code, clean it up, or do much improvement to it.

[aboyes1989]

20 hours ago, Dark Pulse said:

It was definitely time.

 

After Carmack shot down Jim Bagley's original renderer and mandated that it had to use the original renderer, there was pretty much next to no time left before the game needed to be mastered, so Bagley quick-and-dirty ported the PSX version. He didn't have time to sift through the code, clean it up, or do much improvement to it.

 

 

Such a shame that his engine was shot down, and what could have been with the Saturn port. Especially seeing how well Quake ran and looked on the Saturn when moved to the Slave driver engine. 

[Dark Pulse]

38 minutes ago, aboyes1989 said:

Such a shame that his engine was shot down, and what could have been with the Saturn port. Especially seeing how well Quake ran and looked on the Saturn when moved to the Slave driver engine. 

Carmack himself has gone on record saying that in hindsight, he should've let Jim see if he could have come up with a solution to solve the texture swim.

Edited August 13, 2022 by Dark Pulse

[Dexiaz]

There is a Z-Treme/Hellslave Engine, which is homebrew and w.i.p., but looks pretty much interesting:

 

 

I'd like to remade the Doom on this engine, but the map editor is Trenchboom (which is good), and I suck at Quake mapping. This is like the opposite plan to revive Doom on Sega Saturn: instead of fixing the original engine to make it stable I'd made the game again on a new engine.

[aboyes1989]

On 8/13/2022 at 11:47 AM, Dark Pulse said:

Carmack himself has gone on record saying that in hindsight, he should've let Jim see if he could have come up with a solution to solve the texture swim.

 

Absolutely, and if the only issue he had was texture swim then damn why couldn't he just let that go? I guess that's easy to say now, looking back on 32bit games, certain quirks like that add a charm and aesthetic that I know a lot of people enjoy. I guess back in the mid 90s, a programming genius like Carmack just saw that as completely unacceptable. It's a shame really.

[Dark Pulse]

30 minutes ago, aboyes1989 said:

Absolutely, and if the only issue he had was texture swim then damn why couldn't he just let that go? I guess that's easy to say now, looking back on 32bit games, certain quirks like that add a charm and aesthetic that I know a lot of people enjoy. I guess back in the mid 90s, a programming genius like Carmack just saw that as completely unacceptable. It's a shame really.

Carmack was a stickler for not doing anything that would harm the reputation or impressions of the product. He'd rather chop monsters, levels, materials, you name it if that meant that resources could put towards keeping the experience intact.

 

Texture swim definitely can look ugly, especially since it'd have a version of the game that would _not_ swim - several of them, in fact. Don't forget, before the Saturn port came Jaguar, 3DO, 32X, PS1, I think even SNES Doom was out by this time. None of them had that issue (though to be fair, SNES Doom didn't even have textured flats...), so to have one port where it'd suddenly happen would definitely be problematic.

[aboyes1989]

48 minutes ago, Dark Pulse said:

Carmack was a stickler for not doing anything that would harm the reputation or impressions of the product. He'd rather chop monsters, levels, materials, you name it if that meant that resources could put towards keeping the experience intact.

 

Texture swim definitely can look ugly, especially since it'd have a version of the game that would _not_ swim - several of them, in fact. Don't forget, before the Saturn port came Jaguar, 3DO, 32X, PS1, I think even SNES Doom was out by this time. None of them had that issue (though to be fair, SNES Doom didn't even have textured flats...), so to have one port where it'd suddenly happen would definitely be problematic.

 

Yeah that is true, to suddenly show up on a port releasing two or more years after other versions wouldn't look great. However, because of Carmack, the Saturn had a port that played worse than most of the other versions, and looked worse than the PlayStation version, and arguably the Jaguar port too.

 

It is all hindsight, of course. It's easy to look back and think about what should have been done, but it would have been cool to have another unique version of the game. At least another that ran well.

[ludicrous_peridot]

I've added a new small tool to the suite that dumps Sega Saturn Doom sounds from DOOMTONE.BIN ; the output is in DOS Doom (should it be called DMX?) format; reflecting on this a little bit in another thread. 

 

One interesting thing I found while assigning names to the lumps was that contrary to my expectations they did not exactly match the list in PSX source code, which I would have expected, with the value used as an offset to pick the sound to play. sfx_firsht2 (unused in PSX code) and sfx_wpnup (sounds the same as sfx_sgcock) are missing, but otherwise the order of the sounds is exactly the same as in the header linked, which gives an insight into the differences in the port source code to the "original" PSX version. Or I am imagining things :).

 

I tried to map the structs at the start of the .BIN file to actual SCSP control words, but they did not seem match 1 to 1. It appears this was data read by game engine code, and actual control words sent to SCSP were constructed based on the fields of the struct rather then verbatim file contents were sent. One particular outcome of this was that I was unable to find exact sampling frequency used for the PCM data, and ended up "tuning" the sounds manually until the durations were more or less in sync with recording from mednafen, which landed me at 5200Hz. 

 

EDIT: The same format is used in Revolution X (XXXTONE.BIN files are found there) and sampling rate for these is different, but I have no idea where in the file it could be derived from after comparing several files, so leaving it as is.

Edited November 5, 2022 by ludicrous_peridot
revolution x

[fafling]

On 11/5/2022 at 10:28 AM, ludicrous_peridot said:

I tried to map the structs at the start of the .BIN file to actual SCSP control words, but they did not seem match 1 to 1. It appears this was data read by game engine code, and actual control words sent to SCSP were constructed based on the fields of the struct rather then verbatim file contents were sent. One particular outcome of this was that I was unable to find exact sampling frequency used for the PCM data, and ended up "tuning" the sounds manually until the durations were more or less in sync with recording from mednafen, which landed me at 5200Hz. 

 

That's the correct frequency as computation from the SCSP registry values yields the same result.
In the SCSP debug screen of Kronos emulator, Doom sound effects are all played with octave (OCT) value 12 and frequency number switch (FNS) value 909.
Octave is a 4 bit two's complement value, so 12 is certainly an unsigned value and the actual octave is in fact -4.
There's a formula to compute the playback frequency Fs of a sample from these 2 parameters :
Fs = (FNS + 1024) * 44100 / (2^-OCT * 1024)
Which gives precisely 5202,96 Hz.

[taufan99]

On 12/2/2022 at 6:58 AM, fafling said:

That's the correct frequency as computation from the SCSP registry values yields the same result.
In the SCSP debug screen of Kronos emulator, Doom sound effects are all played with octave (OCT) value 12 and frequency number switch (FNS) value 909.
Octave is a 4 bit two's complement value, so 12 is certainly an unsigned value and the actual octave is in fact -4.
There's a formula to compute the playback frequency Fs of a sample from these 2 parameters :
Fs = (FNS + 1024) * 44100 / (2^-OCT * 1024)
Which gives precisely 5202,96 Hz.

All this frequency talk gave me quite a good idea to "reimagine" several other sound effects if they were placed in the Sega Saturn port. *chuckles*

[Wadmodder Shalton]

On 11/27/2021 at 11:49 AM, Mattfrie1 said:

The rumor behind the Japanese version running at a slightly higher FPS has been squashed by others in recent years. The other rumor surrounding this edition, that the CD audio tracks have been rearranged, is also false. The only change in the music for this edition is one CD audio track (A Calm Panic Rises, Track 18 on the PAL and NTSC-U discs) was inexplicably removed from the Japanese CD. This pushes up the running order of the track rotation for the remaining levels in the game starting from Map 10. This also makes the size of the disc slightly smaller for the Japanese version as well (528mb vs. 557mb)

I've always thought that the NTSC-U and NTSC-J versions of Saturn Doom were poorly converted PAL to NTSC conversions, mainly because of the framerate.

[taufan99]

5 hours ago, Wadmodder Shalton said:

I've always thought that the NTSC-U and NTSC-J versions of Saturn Doom were poorly converted PAL to NTSC conversions, mainly because of the framerate.

I don't suppose that'd have been the case for the Sega Saturn port (*cough cough* OG Genesis/Mega Drive port of Shadow of the Beast, anyone?), although I'd be very glad to be proven wrong.

 

Actually y'know what, the Sega Saturn port just could benefit a lot from the reverse-engineered code of both the PSX port and D64 (maybe even Doom 32X Resurrection, as all four are based on the Atari Jaguar port). Again, I'm aware of how notoriously hard Sega Saturn is for third-party developers, but I'm taking my chance to post this just in case a homebrew Sega Saturn developer comes across this. Who knows what stuff they could come up with

[Dark Pulse]

On 12/5/2022 at 5:50 AM, taufan99 said:

Actually y'know what, the Sega Saturn port just could benefit a lot from the reverse-engineered code of both the PSX port and D64 (maybe even Doom 32X Resurrection, as all four are based on the Atari Jaguar port). Again, I'm aware of how notoriously hard Sega Saturn is for third-party developers, but I'm taking my chance to post this just in case a homebrew Sega Saturn developer comes across this. Who knows what stuff they could come up with

Not really. PS1 and N64 are flavors of MIPS, so there is some level of crossover, but the Saturn's SH2 is a totally different instruction set (SuperH), so it wouldn't be so easily transferable.

 

Then again, this was the dawn of most games being programmed in C on consoles, and then potentially being hand-tuned after the fact. Few developers wrote in direct assembly language going forward, and by the time of the next generation (Dreamcast/PS2/GameCube), it was all but dead.

[fafling]

On 4/6/2020 at 12:16 AM, Mattfrie1 said:

@Wesker If you have an Action Replay or other game hacking device for your Saturn you can input the following code that swaps the city sky with the unused Inferno sky. You can leave it active but it will have the reverse effect when you get to the Doom II city levels displaying the Inferno sky instead of the correct one, so make sure you leave it off if you aren't playing through any of the fire sky levels.

 

160769B0 332E
160769C8 332E
16076950 352E
16076968 352E

 

I've also been doing a playthrough of Saturn Doom again for the first time in a while plus some extra tinkering around with the Action Replay, I'll give my notes in a follow-up post.

 

Here's an Action replay code that swaps in the inferno sky without touching the city levels :

https://segaxtreme.net/threads/action-replay-code-for-unused-sky-in-saturn-doom.25309/

Also includes elements that make me think that the use of the city sky instead of the inferno sky was intentional.

[Dexiaz]

On 8/13/2022 at 5:28 PM, Dexiaz said:

There is a Z-Treme/Hellslave Engine, which is homebrew and w.i.p., but looks pretty much interesting:

 

Somethin new:

 

UPD:

 

 

Quote

Here is my latest project : a tech demo showing the first two levels of the classic PC game, Unreal (1998), remade for my own custom Sega Saturn engine - the same one I wrote for Hellslave. This is my entry for the Sega Xtreme 2023 Saturn homebrew competition. For obvious legal reasons, I won't port the whole game - I never planned to go beyond the first 3 levels, which were in the demos. It's in my own engine, so no source code of the original was used and the maps/animation had to be done from scratch. Ponut64 wrote the amazing sound driver while Corvusdeux did most of the 3D models and animations. I coded the tools, the whole game engine and I remade the levels with Trenchbroom - then converted with my own BSP compiler to my own Saturn map format. There are still several glitches and collision issues and the framerate could be improved a lot (it's far from optimized at the moment). The biggest challenge was mostly to make everything fit in RAM. I had to make massive changes to the engine to allow Nyleve falls to work - one week ago it didn't even run without a RAM cart, but the RAM cart is too unreliable, I decided to not use it. I worked on this whole project for around 4 months, with maybe an average of 1 hour per day

 

Trenchbroom, huh? If the engine will be released, possibly Trenchbroom mappers can handle the idea of recreating Doom. Actually, so far I know about tool which converts Doom to Quake map format, but it will require extra work with texturing, lighting and trigger scripting. But still...

Edited December 25, 2022 by Dexiaz

[Individualised]

On 8/13/2022 at 1:28 PM, Dexiaz said:

There is a Z-Treme/Hellslave Engine, which is homebrew and w.i.p., but looks pretty much interesting:

 

 

I'd like to remade the Doom on this engine, but the map editor is Trenchboom (which is good), and I suck at Quake mapping. This is like the opposite plan to revive Doom on Sega Saturn: instead of fixing the original engine to make it stable I'd made the game again on a new engine.

Oddly enough this started out as a Sonic Xtreme mod if memory serves correct.

[Dexiaz]

7 hours ago, Individualised said:

Oddly enough this started out as a Sonic Xtreme mod if memory serves correct.

 

As far as I remember it's true.

 

But this is kinda normal, sometimes it happens. Like, the Aurora Engine (Neverwinter Nights) was reused to create The Witcher 1 (which is very different game). Or RPG Maker was used to create a horror game (Ao Oni).

[fafling]

Reworked the nightmare difficulty AR code : https://segaxtreme.net/threads/action-replay-codes-for-nightmare-difficulty-in-saturn-doom.25268/post-184029

Edited April 25, 2023 by fafling

[fafling]

Fixed a bug in the US master code : https://segaxtreme.net/threads/action-replay-codes-for-nightmare-difficulty-in-saturn-doom.25268/post-184042

[fafling]

@ludicrous_peridotThe link to download your tool for SCR and CHR file conversion gives an error : "We could not locate the item you are trying to view. Error code: 2S328/1".

Internet archive has a snapshot of it from earlier this year : https://web.archive.org/web/20230614191102/https://www.doomworld.com/applications/core/interface/file/attachment.php?id=100754

 

Also the last 2 command lines listed in your post to convert PNG to game formats are using chrtools.png and scrtools.png instead of chrtools.py and scrtools.py.

[Individualised]

On 12/24/2022 at 10:44 AM, Dexiaz said:

 

Somethin new:

 

UPD:

 

 

 

Trenchbroom, huh? If the engine will be released, possibly Trenchbroom mappers can handle the idea of recreating Doom. Actually, so far I know about tool which converts Doom to Quake map format, but it will require extra work with texturing, lighting and trigger scripting. But still...

Been a while but hope XL2 will open source this in the future given that they're no longer working on Saturn homebrew. Would be a massive shame to see this go to waste

Edited September 30, 2023 by Individualised

[Dimon12321]

Did anyone manage to extract the WAD file from Saturn's game image?