DreamSNES 0.9.6 BUG List

Mr._Chips · Post by **Mr._Chips** » Tue Mar 05, 2002 12:23 pm

Also,
Mario RPG, Yoshi's Island do not work as stated on webpage. many games also refuse to save.

sqrt(-1)+1 · Post by **sqrt(-1)+1** » Tue Mar 05, 2002 4:17 pm

The webpage says "Yoshi's Island (and other SuperFX games) no longer crashes DreamSNES", which seems to be true. Compare with 0.9.4 where starting Yoshi's island would lock up the emulator. :-) I've managed to crash it with Doom though.

Ex-Cyber · Post by **Ex-Cyber** » Wed Mar 06, 2002 5:42 am

I have a feeling that pretty much all the score/math bugs are rooted in a problem with decimal mode emulation in the 65816 core. While I haven't actually disassembled anything to see if this is the case, I think it's fairly likely. Decimal mode is a mode of the 6502 and 65816 that is intended for doing math in binary coded decimal (BCD), which is a special type of numeric encoding that represents two decimal digits in a binary byte.

The NES's 6502 core doesn't have decimal mode (or at least has a really funky version that only works on a few instructions). This may have led to a misunderstanding regarding its implementation, as there seems to be much more documentation available for NES 6502 than 65816 (most introductions to 65816 assume 6502 knowledge, since it was typically used as a 6502 replacement). In fact, I don't think I've ever seen a detailed description of decimal mode. Anyway, a routine intended to do math in BCD would get incorrect results if calculated normally. This would result in incorrect math as has been reported. The instances in which calculations continue "forever" until interrupted (e.g. the score totals in SF2 Turbo) are probably due to the program waiting for a particular result (most likely a value being equal to zero) that don't occur in the expected number of operations, or don't occur at all, which results in the loop continuing indefinitely (or at least for a much longer time than expected). Decimal mode is rarely, if ever, used for critical graphics/sound calculations (e.g. sprite positioning or calculating BG table addresses), though, so it's not an immediately obvious bug when dealing with a game console. Perhaps the decimal mode emulation in the new CPU core was incomplete and disabled to get this release out because the author(s) didn't think it was important enough to hold up the release.

As for the compression thing, it's entirely possible (and likely) that some games compress their data before writing it to SRAM. Running a compression algorithm on compressed data generally doesn't do much good. And, as has been previously implied by someone else, it's mathematically impossible for a given compression algorithm to compress all possible data sets (for an explanation of this, try a Google search for "pigeonhole principle").

Hope this sheds a little light on the subject, at least.

Boogerman · Post by **Boogerman** » Wed Mar 06, 2002 5:48 am

Yoshis Island works and Mario RPG has worked since 0.9.3

mc · Post by mc » Wed Mar 06, 2002 12:47 pm

Ex-Cyber wrote: I have a feeling that pretty much all the score/math bugs are rooted in a problem with decimal mode emulation in the 65816 core. While I haven't actually disassembled anything to see if this is the case, I think it's fairly likely. Decimal mode is a mode of the 6502 and 65816 that is intended for doing math in binary coded decimal (BCD), which is a special type of numeric encoding that represents two decimal digits in a binary byte.

And I'm fairly confident that this is not the case. Because of the
relative obscurity of the BCD mode, the decimal ADC/SBC instructions
are the only ones in the CPU core which have undergone exhaustive automatical
testing and thus are proven correct for all input values.

If it wasn't for this fact, I'd agree with you though. :-)

Mr._Chips · Post by **Mr._Chips** » Thu Mar 07, 2002 12:38 am

Boogerman wrote:Yoshis Island works and Mario RPG has worked since 0.9.3

So how come they both freeze up my DC (even with saving off) ??

mirrorsaw_2000 · Post by **mirrorsaw_2000** » Thu Mar 07, 2002 3:35 am

Mr._Chips wrote:
Boogerman wrote:Yoshis Island works and Mario RPG has worked since 0.9.3
So how come they both freeze up my DC (even with saving off) ??

Bad roms perhaps? Yoshi's Island loads up fine for me, although it's terribly slow (45-50%).

Boogerman · Post by **Boogerman** » Thu Mar 07, 2002 4:25 am

Yeah, if a ROM doesn't work, boot it up in SNES9x on PC and see if it runs in that... that should tell you if it's a bad ROM or not

Akuma[] · Post by **Akuma[]** » Thu Mar 07, 2002 8:42 am

Bug??? If there is zero free space on your memory card you will get booted back to the menu when you try to start a game.

mirrorsaw_2000 · Post by **mirrorsaw_2000** » Thu Mar 07, 2002 9:10 am

Kirby Superstar locks up DreamSNES.

StriderXg2 · Post by **StriderXg2** » Thu Mar 07, 2002 10:31 am

Akuma[] wrote: Bug??? If there is zero free space on your memory card you will get booted back to the menu when you try to start a game.

Actually, if you dont have enough space and you load a game it should tell you how many blocks it needs. for example yoshi's island keeps going and needs 20 blocks to save(yet it flashes this annoyingly repeatedly and asks for a different number every time) and the same with Earthbound.

Btw Yoshis' Island for me works about 70%...different for everyone i guess

nakamichi · Post by **nakamichi** » Thu Mar 07, 2002 2:34 pm

Tested some more ROMs,nearly tested about 300! of 'em so far...
Here's another bug update:

* Y's V:Expert (jap) :
Annoying pops and crackles in the sound all of the time and severe screen "blinking" in some places.

* Captain Commando :
The score gets all weird and messy.

* Bubsy :
The +60 lives bug is also in this game,but unlike in the other games,it has no effect to the number of lives,only the "lives indicator" blinks and shows 60+x lives,but when you lose those "x" lives you have,the game ends like it should have...
Just those blinking fake number of lives annoy me.

*** (!) CORRECTION (!)
The "bug" in Hook I've mentioned before is NOT a bug...enemies really don't give any score.I've tested that with other verisons of DSNES and I think the game is made that way by the programmers.So,there's NO bugs with Hook. Sorry.

Until my LAST update (I think I tested nearly ALL 350 ROMs I have),sayo~nara.

Wow,this bug list is becoming popular :) I hope these bugs will get exterminated in the next release.

C YA DSNES fans...

Akuma[] · Post by **Akuma[]** » Fri Mar 08, 2002 1:12 pm

StriderXg2 wrote:
Akuma[] wrote: Bug??? If there is zero free space on your memory card you will get booted back to the menu when you try to start a game.
Actually, if you dont have enough space and you load a game it should tell you how many blocks it needs. for example yoshi's island keeps going and needs 20 blocks to save(yet it flashes this annoyingly repeatedly and asks for a different number every time) and the same with Earthbound.

Btw Yoshis' Island for me works about 70%...different for everyone i guess

Thats not a bug!! Thats suppose to happen!

I'm talking about if you have "ZERO" or "0" free space on the vmu you will get booted to the main menu where you can change the settings, select game etc...

I havn't tried playing without a memory card yet but I'll try it later and see what happens!

StriderXg2 · Post by **StriderXg2** » Sat Mar 09, 2002 12:28 pm

Akuma[] wrote:
StriderXg2 wrote:
Akuma[] wrote: Bug??? If there is zero free space on your memory card you will get booted back to the menu when you try to start a game.
Actually, if you dont have enough space and you load a game it should tell you how many blocks it needs. for example yoshi's island keeps going and needs 20 blocks to save(yet it flashes this annoyingly repeatedly and asks for a different number every time) and the same with Earthbound.

Btw Yoshis' Island for me works about 70%...different for everyone i guess
Thats not a bug!! Thats suppose to happen!

I'm talking about if you have "ZERO" or "0" free space on the vmu you will get booted to the main menu where you can change the settings, select game etc...

I havn't tried playing without a memory card yet but I'll try it later and see what happens!

i know, i was saying what you had said in your last post wasnt a bug, as well.

nakamichi · Post by **nakamichi** » Mon Mar 18, 2002 3:46 pm

Even more bugs this time...

* Zenki (jap)
I found a score/lives bug in this game as well.
Your score gets up to 99999990 in a short time and your lives go up to 99! This is not fair (no challenge)

* QIX (the hidden game)
I wish also the QIX hidden mini-game included in DSNES 0.9.6 was fixed.It has a "bug" which makes the game unfair and not true to the original.When you lose a life,all the cleared area is gone!
In the REAL QIX,the area stays until it's GAME OVER or stage clear,so for now I cannot play this game

(what a pity,QIX is my favorite game,BTW)

More bug reports after I finish Super Metroid with a new record time

...that's why I'm kinda slow these days...

***DSNES TEAM,PLEASE READ THIS***

-> If anyone of the DreamSNES team wants to include a music track(MP3 file) made by myself with a Dreamcast(!) in the next release of DreamSNES... I have several good tracks to be used as a DreamSNES menu BGM

And what about playing a MIDI file instead of a MP3 in the background for much faster ROM loading(only while loading ROMs)?

-> Also how can I contribute with a translation for the next DreamSNES? I like to do translations in several other languages which were not included in DSNES 0.9.6...

Nakamichi Synth Station
http://www.mp3.com/synthstation
coming soon!

Ima sayo~nara...
(damn,I can't type Kanji with PlanetWeb...and I CANNOT post with DreamPassport...I wish I could be able to post with my Dream Passport...I'm now stuck with this PlanetWeb thing...grrr!)

xzoner2 · Post by **xzoner2** » Mon Mar 18, 2002 4:39 pm

2 more bugs

*Earthworm Jim 2* Lots of sound effects are missing like being hit for example

*Robocop vs Terminator 2* flickers like mad i cant enjoy the game without getting a seizure

Does anyone else have these problems or just bad roms?

AesclepiusCrow · Post by **AesclepiusCrow** » Tue Mar 19, 2002 6:46 am

Here's one, but maybe it's just me.

During the play of a certain few games featuring menus like Final Fantasy V and VI, I'm getting very twitchy keypress response. Works fine with other RPGs, game works fine in Snes9x, and even other Squaresoft games seem to be fine with it. Anyone else having really odd responses from button press? A good example would be, pressing a button, not having a response, pressing it again, then having the first and second button press working all at once. (Like talking to townspeople, pressing a button to escape, having nothing happen, then pressing again to have the speech window close, and then repop up.) It may actually be my controller, but I haven't had any trouble with any others. Perhaps a problem with frame skip actually ignoring keypress commands? Anyone?

nakamichi · Post by **nakamichi** » Thu Mar 21, 2002 5:02 pm

*CHECK the checksum of your ROMs first before posting*

Those two "bugs" which you noticed are not bugs at all.You must have a bad dump of the ROM(Earthworm Jim).I've tested my ROM and it works 100% correct with ALL sound effects.Before you post,make sure to check whether you have a good ROM or not.To do this,run the ROM on SNES9x 1.37 or later(v1.39) on your PC and see if it displays a message "Checksum OK".Only then you have a good non-hacked ROM.Make sure you run ROMs with good chcksums on your DreamSNES 0.9.6 before posting bug reports.About the Final Fantasy games,there is no problem with these games for me.I checked FF5 and FF4 and they were O.K.The response lag in certain games is probably due to the severe frameskip which actually affects the key response in some way.It is NOT a bug,ad it will be corrected when the emulation is speeded up and the frameskip is lowered so the frameskipping has less effect on the control response time.
An example of ho framesip actually affects controls is when you run MAMED on your DC and set frameskip to 10 or 11.But if the game runs only 25-30% speed,but with NO frameskip,the controls are more responsive,but everyting is very slow.

* About DOOM :
This game probably doesn't run because this version of DreamSNES is based on a version of SNES9x older than v 1.39 (I think it's 1.37).I've tried running DOOM on SNES9x 1.37 and it DOESN'T WORK,but with 1.39 it WORKS!

So for some non-working ROMs it's not the DreamSNES programmers' fault,but the version of SNES9x they used as a base has the same problems,similar case is with MAMED for DC.

*** GOOD GAMES THAT RUN ~100% ***

Tired of games running slow on your DreamSNES and you want a fast AND good overhead view shooter?
Try "Flying Hero Bugyuru" (japanese)! It moves very smoothly even with STEREO sound !
Also try "Metal Warriors" (US) in 60Hz with mono sound...man,this game is faaast!
and "BlazeOn" (US).It moves very fast,almost 100% w/sound!
* FOR RETRO FANS ONLY!!! *
Try "Nichibutsu Arcade Classics vol.1" (japanese).This game is a must-have for retro arcade fanatics!
Also the "Tecmo Shooting Collection" (japanese) is a wonderful game to have for retro shooter freaks.
And the "Ninja Gaiden(I like the name Ryukenden more) Trilogy" is a blast from the past!

Well,that's all for today...
Post bugs if you find 'em,but CHECK the ROMS first,then post a report.
Gotta test s'more ROMs...mata ne~
-----------------------------------
I'd like to see some Kanji! I'm tired of his ASCII font :)

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< NAKAMICHI >

DreamSNES 0.9.6 BUG List

Make sure you check the checksum of the ROM before you post