Jump to content
IGNORED

Testing the new Stella TIA core


stephena

Recommended Posts

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
Link to comment
Share on other sites

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
  • Like 2
Link to comment
Share on other sites

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
Link to comment
Share on other sites

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.

Link to comment
Share on other sites

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
Link to comment
Share on other sites

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.

Link to comment
Share on other sites

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.

  • Like 2
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...