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Testing the new Stella TIA core

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Also, that's a good upportunity to EF[sC] to 6502.ts. Are you perchance hitting NUSIZ just when the first pixel is being rendered?

 

So the missile (M1) is also being moved - something like:

 

0000XX

000XX0

00XX00

00XX00

000XX0

0000XX

 

but shown as:

 

0000X0

000X00

00X000

00X000

000X00

0000X0

 

So I don't think it's an off by one pixel, but it could be off by one machine cycle......I haven't looked at the code for literally years, so I wouldn't like to promise that the old Stella TIA core had it right......I have the source code on an old HDD somewhere, so as Thomas suggests I should maybe try to build a version that works on normal Harmony at some point, if I remember correctly the bank switching etc.. was pretty tight and it wouldn't be as straightforward as you might think to change the bank switching scheme..

Edited by eshu

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Hi eshu!

 

I just had I a look at the ROM --- woha, that looks awsome, I wouldn't believe that this is actually a 2600 if I didn't know better :) I just received shipping confirmation for my Harmony Encode, so I should be able to test this on real hardware soon.

Edited by DirtyHairy
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The "0" (zero) is finally fixed on Pole Position.

I knew it would be. Stella 5: Atari original.

post-29575-0-10719300-1481791002_thumb.png post-29575-0-87983400-1481791024_thumb.png

 

 

Stella 5: Hacked curve and color. Stella 4.7.2: Hacked curve and color.

 

post-29575-0-49914100-1481791075_thumb.png post-29575-0-31587500-1481791088_thumb.png

 

 

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Noticed this little dot on the left side on both the old core and the new core. Don't know if it has ever been addressed?

post-4806-0-85444400-1481827716_thumb.pngpost-4806-0-89741700-1481827717_thumb.pngpost-4806-0-00612100-1481827719_thumb.png

 

On the lower right-hand corner, by the red stripe, there is a black mark. Also don't know if this has ever been addressed. Same in old/new cores.

post-4806-0-60610100-1481827715_thumb.png

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That's no bug in emulation. All those glitches (plus a few more) happen on (my) real hardware too.

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Vong has a constant background tone during gameplay.

 

Note: I only have emulation to test with, and my comparisons are made with the older versions of stella vs these pre-releases. Hope that is helpful.

Edited by Keatah

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Thanks for checking out pole position and for confirming that the remaining glitches happen on real hardware, too :) I'll check out Vong, but nothing has changed regarding audio emulation.

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Meltdown by 20th Century Fox Look'n Good!

The rods are now symmetrical in all columns.

 

Before:

post-4806-0-14044200-1481931591_thumb.png

 

New TIA:

post-4806-0-94819700-1481931589_thumb.png

post-4806-0-79603400-1481931752_thumb.png

 

New TIA with phosphors option to blend the two alternating frames together:

post-4806-0-97009600-1481931957_thumb.png

 

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This bug is about game speed and framerates.

 

Starting out with any game and the framerate set to AUTO.. it's cool.

 

AND once you got a rom loaded and are playing, in this test build, using Tab> Video Stettings> Framerate> 10

The game slows down to 10 frames-per-second as expected. And it displays 10 FPS in the upper lefthand corner. As expected. Good.

 

---

 

But if you go back and set it to AUTO, the game stays at 10 FPS and the little counter in the upper lefthand corner says 0 FPS. The game continues playing at 10 FPS

 

Setting it to 60 FPS restores normal speed.

Setting it AUTO now, it stays at the last setting, of 60, but display 0 FPS

 

If you exit the game to the selector and start again, it's normal again till you change the speed. It's kinda like once you select a speed manually you can't get back to AUTO.

 

This happens on NTSC, don't know about PAL or if turning VSYNC off changes the behavior.

 

---

 

Dunno if that's a TIA core issue or how the TIA core connects to the interface. I'm not an expert programmer.

Edited by Keatah

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Stephen,

 

The "modifier key" Cmd + M doesn't toggle HMOVE blanks seen in "debug colors".

 

Mac OS X latest (Sierra)

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Re: Meltdown.

It does look good, but is it CORRECT ?

 

Your phosphor shot shows the right 2 looking different than the left two rods.

Aren't they all displayed looking the same? Or is that screen shot not capturing properly?

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The screenshot is accurate. I didn't have time to go and correct my posting to comment that it is an improvement, but not quite there.

Edited by Keatah

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Stephen,

 

The "modifier key" Cmd + M doesn't toggle HMOVE blanks seen in "debug colors".

 

Mac OS X latest (Sierra)

For me this is independent from the debug colors. I cannot disable HMOVE blanks at all.

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This bug is about game speed and framerates.

 

This is a known issue, and is being worked on.

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The "modifier key" Cmd + M doesn't toggle HMOVE blanks seen in "debug colors".

 

Toggling of HMOVE blanks has been completely removed. The new core doesn't draw anything in the HMOVE blank area, so there is nothing to toggle (the area is always black). The fact that you could ever see anything at all in this area was a peculiarity of the old core; it wasn't correct emulation.

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Re: Meltdown.

It does look good, but is it CORRECT ?

 

Your phosphor shot shows the right 2 looking different than the left two rods.

Aren't they all displayed looking the same? Or is that screen shot not capturing properly?

 

Indeed, you are right. I've made some adjustements to NUSIZx during decode, and it looks OK now. You can find more screenshots attached to the corresponding ticket on github https://github.com/DirtyHairy/stella/issues/36 (those at the bottom of the page are the final ones).

 

8801f2ee-c4a1-11e6-9ec1-197ac4b870c3.png

Edited by DirtyHairy

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Dunno if that's a TIA core issue or how the TIA core connects to the interface. I'm not an expert programmer.

 

The latter ;-) Stella manages speed in terms of frames, while 6502.ts manages it in terms of pixel clocks. Therefore, the 6502.ts core did not initially contain the logic necessary for Stella to maintain a constant framerate.

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In case someone hasn't noticed yet, there is a 3rd pre-release which includes quite some more bug fixes of the new core and improvements over the old core.

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I tested "Snoopy and the Red Baron", which in the stable Stella version has problems displaying the cloud and mountains, both made of a combination of players, missiles and playfield graphics updated and repositioned every line.

Screenshots of the game in various Stella versions with and without "debug colors":

post-10599-0-97094500-1482339754_thumb.pngpost-10599-0-04432600-1482339754_thumb.png

post-10599-0-15060700-1482339772_thumb.pngpost-10599-0-24672200-1482339771_thumb.png

post-10599-0-35163900-1482339770_thumb.pngpost-10599-0-40459400-1482339769_thumb.png

post-10599-0-56013000-1482339768_thumb.pngpost-10599-0-61173000-1482339767_thumb.png

real hardware:

post-10599-0-18288300-1482339753_thumb.jpg

post-10599-0-20524800-1482339748_thumb.jpg

post-10599-0-31560700-1482339751_thumb.jpgpost-10599-0-86966500-1482339749_thumb.jpg

 

 

 

5.0.0pre3 is closest to real hardware, the only issue seems to be a missing pixel in the left mountain.
Real hardware screenshot is from my 7800 which has composite mod. It shows some color bleed, so it's difficult to see every pixel. Unfortunately my S-video modded 6-switch (which has a much clearer video out) needs some servicing. Maybe an hack of the game that only displays Players OR Missiles would help in debugging the problem.
I used PAL version of the game, but apart for the different colors, the NTSC has the same behaviour.

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I am not so sure if the single pixel is the only bug. But that's really hard to tell.

 

Two PAL versions w/o player or missiles attached.

Snoopy (no players).bin

Snoopy (no Missiles).bin

Edited by Thomas Jentzsch
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Thanks for the hacked roms. I managed to take better pictures (I purposely misadjusted the color pot on the board in order to get a crisp B/W image).
Hardware: PAL 7800 (board C300633-001 rev. C), TIA chip produced in 1989.

post-10599-0-28268200-1482358194_thumb.jpg

post-10599-0-43145900-1482358184_thumb.jpgpost-10599-0-03466700-1482358187_thumb.jpg

 

Missiles only:

post-10599-0-23448700-1482358196_thumb.jpgpost-10599-0-36877700-1482358199_thumb.jpg

 

Players only:

post-10599-0-77158400-1482358189_thumb.jpgpost-10599-0-44194900-1482358192_thumb.jpg

Hope it helps.

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This was fixed a few minutes ago, by checking another ROM, MESS and on real hardware. The missiles were 1 pixel too far right.

 

Thanks for making us aware.

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