Report all your Stella bugs here (TIA, GUI, etc)

[+stephena]

OK, after a long break it looks like we have a few more developers back on board for Stella, and we want the next release to be a big bug-fix release. So, can everyone report their bugs here. Just a few pointers:

 

1) Please try the latest version of Stella (v/2.2) before reporting a bug, as it may already have been fixed.

 

2) If it's a rendering/TIA bug, please include as detailed a description as possible (name/version of ROM, exactly how it isn't working and how it should be working, etc).

 

3) Be as detailed as possible; include operating system used, video card, sound card, rendering mode (software or OpenGL), or anything else you feel would help.

 

At some point, we'll be activating the Sourceforge bug tracker for Stella, so there'll be a much better way to report and track the progress of bugs. But for now, this forum will have to do.

 

So, please do some intensive testing. We can't improve Stella if we don't know about the problems ...

[+Trebor]

Hi stephena,

 

I believe the screenshots provide all the details you need:

 

 

-Trebor

Edited August 19, 2006 by Trebor

[supercat]

1) Please try the latest version of Stella (v/2.2) before reporting a bug, as it may already have been fixed.

 

I just downloaded Stella from SourceForge and it was 2.1; also, how do I use Stella to run bins? It just seems to like zips?

 

Here's a couple bins to try. The first is mishandled by Stella 2.1 but correctly in Z26; there should be yellow vertical lines on either side of the logo, generated via repeat RESBL stores.

 

The second demo is mishandled by Z26 and Stella 2.1. The red diagonal line is Player 0; the yellow one is the Ball; the green diagonal line is player zero. The vertical lines are all playfield (score mode). Stella is closer to accurate than Z26, but neither is right.

 

The red vertical lines should cover up everything. The green vertical lines should cover everything but the red diagonal line. The best way to patch Z26 to acommodate this is to have a third version of the sprite ordering table, used for score mode (presently Z26 uses two copies, for playfield-in-front or playfield-behind). In this third copy, the ball should be behind the playfield and both sprites; the playfield should be behind Player/Missile 0 but in front of Player/Missile 1.

jf2.bin

test.bin

Edited August 19, 2006 by supercat

[+stephena]

Hi stephena,

 

I believe the screenshots provide all the details you need:

 

-Trebor

Thanks for that, I've already reported this bug to the TIA guys, but it's nice to see some screenshots of it.

[+stephena]

1) Please try the latest version of Stella (v/2.2) before reporting a bug, as it may already have been fixed.

 

I just downloaded Stella from SourceForge and it was 2.1; also, how do I use Stella to run bins? It just seems to like zips?

I just checked, and the latest version on Sourceforge *is* 2.2. Maybe you could try another mirror or something?? As for running a bin, if you launch from the commandline it's just 'stella NAME_OF_ROM'. That file could be either a bin or a zipfile; Stella will figure it out and use it.

Here's a couple bins to try. The first is mishandled by Stella 2.1 but correctly in Z26; there should be yellow vertical lines on either side of the logo, generated via repeat RESBL stores.

This works with the current CVS code, so that's one taken care of I'll forward the second bug to Brad.

[+Trebor]

Phoenix, as seen here:

 

 

No background music/melody.

 

Same ROM (Offline list verified) has background music/melody in Z26.

 

***UPDATE EDIT: Please ignore. I forgot the difficulty switches affect whether the melody plays or not.

ROM works fine.

 

-Trebor

Edited August 24, 2006 by Trebor

[yuppicide]

I just noted a problem with the latest version 2.2 for Windows.

 

I had Adobe Photoshop CS2 open. I minimized and opened Stella 2.2, full screen of course. I opened a game and played it for a few seconds taking a screenshot.

 

Closed Stella and went back to Photoshop and my screen was messed up! The right side where you have colors, layers, etc, was dragged into the middle of the screen!

 

I have no problems with Photoshop other than Stella.

 

Another thing.. is there two different screenshot keys or something?! I took 4 screenshots in a game.. one came out small (304 x 190) and the other three came out large (608 x 380) double size of the first.

Edited August 29, 2006 by yuppicide

[+batari]

Here's another possible bug: Stella does not seem to change SWCHB bits for difficulty and color/BW switches if you switch them during a frame when SWCHB is not read.

[SeaGtGruff]

I noticed a weird bug in the TIA enable/disable feature. It seems that sometimes the playfield will be displayed, even though it's disabled. It seems to happen when certain combinations of the other TIA objects are enabled. The following screenshots show what I mean. These are from my Sudoku WIP:

 

Sudoku.bas.bin (Note: Run with E7 M-Network bankswitching.)

 

Here is a screenshot with everything disabled; only the background color is being drawn:

 

 

Here is a screenshot with only P0 enabled (phosphor effect on):

 

 

Here is a screenshot with only P1 enabled (phosphor effect on):

 

 

Here is a screenshot with only M0 enabled (phosphor effect on):

 

 

Here is a screenshot with only M1 enabled (phosphor effect on):

 

 

Here is a screenshot with only BL enabled:

 

 

Here is a screenshot with only PF enabled:

 

 

Okay, now here is a screenshot with only P0 and M0 enabled. Notice that the playfield lines in the grid are visible:

 

 

Next, here is a screenshot with only P0 and M1 enabled. Again, notice the playfield lines in the grid:

 

 

Next, here is a screenshot with only P0 and BL enabled. Notice the playfield in the title bar-- but only on the scanlines where P0 is drawn-- as well as the playfield line in the grid-- but only on the right half of the screen, just above where the ball is drawn. This doesn't happen with P1 and BL, by the way, only with P0 and BL:

 

 

Next, here is a screenshot with only P1 and M0 enabled. Note the playfield lines in the grid:

 

 

Next, with only P1 and M1 enabled:

 

 

Finally, with only M0, M1, and BL enabled. If either M0 or M1 are disabled, the playfield line disappears:

 

 

MR

[+stephena]

I just noted a problem with the latest version 2.2 for Windows.

 

I had Adobe Photoshop CS2 open. I minimized and opened Stella 2.2, full screen of course. I opened a game and played it for a few seconds taking a screenshot.

 

Closed Stella and went back to Photoshop and my screen was messed up! The right side where you have colors, layers, etc, was dragged into the middle of the screen!

AFAIK, this is a side effect of SDL in Windows, when toggling between fullscreen and windowed mode. If SDL switches to a fullscreen resolution different from the desktop one, when it switches back it sometimes rearranges whatever was on the desktop. It happens with all SDL Windows apps, not just Stella. If possible, I suggest to use OpenGL mode and turn on the option to use 'Desktop res in fullscreen mode'. In that case there won't be a resolution change, and the desktop windows won't be rearranged.

Another thing.. is there two different screenshot keys or something?! I took 4 screenshots in a game.. one came out small (304 x 190) and the other three came out large (608 x 380) double size of the first.

OK, there are two issues here:

 

1) Non-standard window sizes are because some ROMs are tweaked to show only the 'usable' portion of the screen, and not the missing portions, as it would be displayed on a real machine. The latest version has a toggle button to not do this (ie, to show *all* content), and the next version of Stella will remove these tweaks completely.

 

2) A screenshot is taken at the current zoom level. So if you zoom to 1 and take a snapshot, you get one of approx. 320x200 or so. If you zoom to 2, then snapshots will be approx. 640x400, etc.

[+stephena]

Here's another possible bug: Stella does not seem to change SWCHB bits for difficulty and color/BW switches if you switch them during a frame when SWCHB is not read.

I noticed a weird bug in the TIA enable/disable feature. It seems that sometimes the playfield will be displayed, even though it's disabled. It seems to happen when certain combinations of the other TIA objects are enabled. The following screenshots show what I mean. These are from my Sudoku WIP:

OK, I will look into these.

[jbanes]

I noticed a weird bug in the TIA enable/disable feature. It seems that sometimes the playfield will be displayed, even though it's disabled. It seems to happen when certain combinations of the other TIA objects are enabled. The following screenshots show what I mean. These are from my Sudoku WIP:

OK, I will look into these.

FYI, I've seen this bug in Pitfall II as well. The playfield renders on the left-hand side of the screen, where-ever sprites are. In addition, just disabling the playfield fails to make waves go away. Instead, the playfield and (I think it was missiles) have to be disabled to stop the waves.

[yuppicide]

AFAIK, this is a side effect of SDL in Windows, when toggling between fullscreen and windowed mode. If SDL switches to a fullscreen resolution different from the desktop one, when it switches back it sometimes rearranges whatever was on the desktop. It happens with all SDL Windows apps, not just Stella. If possible, I suggest to use OpenGL mode and turn on the option to use 'Desktop res in fullscreen mode'. In that case there won't be a resolution change, and the desktop windows won't be rearranged.

 

Okay. Thanks I will try those suggestions.

 

Another thing.. is there two different screenshot keys or something?! I took 4 screenshots in a game.. one came out small (304 x 190) and the other three came out large (608 x 380) double size of the first.

 

1) Non-standard window sizes are because some ROMs are tweaked to show only the 'usable' portion of the screen, and not the missing portions, as it would be displayed on a real machine. The latest version has a toggle button to not do this (ie, to show *all* content), and the next version of Stella will remove these tweaks completely.

 

2) A screenshot is taken at the current zoom level. So if you zoom to 1 and take a snapshot, you get one of approx. 320x200 or so. If you zoom to 2, then snapshots will be approx. 640x400, etc.

 

I'm confused. The screenshots were all from the same game.. I did them one after the other.. Jungle Hunt. 3 of them came out 304 x 190 and one came out 608 x 380.

[+Trebor]

Pitfall II extra sound chip improvements perhaps (?) I don't know how else to phrase it. Neither Z26 nor Stella sound like the real cart playing on an actual 2600. Both Stella and Z26 sound different from each other too. Can this be improved? Who's more accurate?

 

-Trebor

[+Trebor]

H.E.R.O. on various screens in levels 5-7 (Perhaps other levels as well):

 

 

A red lines appears like the laser that you shoot on the left side of the screen, and follows the vertical movement of your character within a certain range of scanlines.

 

-Trebor

[+SpiceWare]

Not a bug - but a request.

 

How about a way to make the emulator run as fast as possible? I'm testing Medieval Mayhem for "out of time" conditions that occur by using breakif { _scan==#263 } and then letting it run. The past few times it's taken a few hours for the condition to occur. If I could tell Stella to run as fast as possible then the tests could go quicker.

 

I saw an option to control framerate under Video Settings that seemed to imply I could make it run up to 5 times faster. Setting it below 60 results in Stella running slower. Setting it faster resulted in Stella running at normal speed. I'm running Stella 2.2 under OS X.

[+stephena]

Not a bug - but a request.

 

How about a way to make the emulator run as fast as possible? I'm testing Medieval Mayhem for "out of time" conditions that occur by using breakif { _scan==#263 } and then letting it run. The past few times it's taken a few hours for the condition to occur. If I could tell Stella to run as fast as possible then the tests could go quicker.

 

I saw an option to control framerate under Video Settings that seemed to imply I could make it run up to 5 times faster. Setting it below 60 results in Stella running slower. Setting it faster resulted in Stella running at normal speed. I'm running Stella 2.2 under OS X.

I'm betting it's because the main render loop in Stella is tied to framerate, and if you're using OpenGL it's probably syncing to vblank (60 fps on most machines). Try turning that off (it's a Mac thing, not Stella), or switch to software rendering mode. Or maybe OSX syncs to vblank in software mode too??

[bwmott]

I noticed a weird bug in the TIA enable/disable feature. It seems that sometimes the playfield will be displayed, even though it's disabled. It seems to happen when certain combinations of the other TIA objects are enabled. The following screenshots show what I mean. These are from my Sudoku WIP:

OK, I will look into these.

FYI, I've seen this bug in Pitfall II as well. The playfield renders on the left-hand side of the screen, where-ever sprites are. In addition, just disabling the playfield fails to make waves go away. Instead, the playfield and (I think it was missiles) have to be disabled to stop the waves.

The TIA object enable and disable functions were added after the original TIA code was developed. Inside the TIA code the state of the TIA object flags are "cached" in pointers to precomputed tables for drawing the frame. I'm guessing these table pointers are not being updated when the enable/disable methods are invoked.

 

I'm making a number of changes to the TIA code for the next release and will attempt to address this issue during that work.

 

-- Brad

[bwmott]

H.E.R.O. on various screens in levels 5-7 (Perhaps other levels as well):

 

 

A red lines appears like the laser that you shoot on the left side of the screen, and follows the vertical movement of your character within a certain range of scanlines.

 

-Trebor

I'll look into this while I'm working on the TIA code for Stella.

 

-- Brad

[bwmott]

Here's another possible bug: Stella does not seem to change SWCHB bits for difficulty and color/BW switches if you switch them during a frame when SWCHB is not read.

Could you say more about this issue? Is this when the debugger is open or during normal execution?

 

Thanks,

 

-- Brad

[bwmott]

Pitfall II extra sound chip improvements perhaps (?) I don't know how else to phrase it. Neither Z26 nor Stella sound like the real cart playing on an actual 2600. Both Stella and Z26 sound different from each other too. Can this be improved? Who's more accurate?

 

-Trebor

There are no plans for doing any sound emulation changes for the next release, however, I'll add this to the list of items to look into for later releases.

 

-- Brad

[+SpiceWare]

I'm betting it's because the main render loop in Stella is tied to framerate, and if you're using OpenGL it's probably syncing to vblank (60 fps on most machines). Try turning that off (it's a Mac thing, not Stella), or switch to software rendering mode. Or maybe OSX syncs to vblank in software mode too??

I have it set to software mode. OpenGL mode runs slow for some reason.

[+stephena]

I noticed a weird bug in the TIA enable/disable feature. It seems that sometimes the playfield will be displayed, even though it's disabled. It seems to happen when certain combinations of the other TIA objects are enabled. The following screenshots show what I mean. These are from my Sudoku WIP:

OK, I will look into these.

FYI, I've seen this bug in Pitfall II as well. The playfield renders on the left-hand side of the screen, where-ever sprites are. In addition, just disabling the playfield fails to make waves go away. Instead, the playfield and (I think it was missiles) have to be disabled to stop the waves.

The TIA object enable and disable functions were added after the original TIA code was developed. Inside the TIA code the state of the TIA object flags are "cached" in pointers to precomputed tables for drawing the frame. I'm guessing these table pointers are not being updated when the enable/disable methods are invoked.

Yes, that's probably my fault, since I added this enable/disable code, and didn't really understand the entire TIA class.

[+stephena]

I'm betting it's because the main render loop in Stella is tied to framerate, and if you're using OpenGL it's probably syncing to vblank (60 fps on most machines). Try turning that off (it's a Mac thing, not Stella), or switch to software rendering mode. Or maybe OSX syncs to vblank in software mode too??

I have it set to software mode. OpenGL mode runs slow for some reason.

Yes, but I believe OSX renders even software buffers to an OpenGL texture, and somewhere in the system settings (Quartz, compositing??) these updates are sync'ed to the screen refresh rate. I know that can be turned off; I just don't know where (I *have* done it, so I'm sure it can be done).

[cd-w]

This isn't a bug, but it would be nice if it was possible to disable the supercharger loading bars. It can be a pain waiting for them to finish when doing SC development.

 

Chris