SMS core

[Newsdee]

Let's all give a big thanks to Sorgelig for porting the SMS core! It works really well!

[NegSol]

Thank you Sorgelig !! Great port!

I uploaded a short video captured from he HDMI Output.

https://youtu.be/yPHEmD2lN-U - SMS Core 20171002

At the moment the core does not offer any filter options for the picture. However some filtering appears to be applied.
While the VGA output looks nice and sharp, the HDMI output produces artifacts around object borders and looks blurry.

Still very decent port and a huge improvement compared to the existing MiST version. Great addition to the MiSTer core line up.

Cheers!

[Sorgelig]

Actually i regret the time i spent for porting this core. Compatibility with games are very low.
So, don't expect much from this core.

[Newsdee]

It's still a good example of how to port a core, so it's no wasted effort. Plus the games that do work are fun!

[NML32]

I'm always happy to see a new core ported over to MiSTer.
Thanks!!

[GreyRogue]

As mentioned in this thread, I found that the SMS core was having issue with SDRAM access timing:
http://www.atari-forum.com/viewtopic.php?f=117&t=34189#p354216
Testing with the FPGA's built-in RAM seemed to fix issues.
I decided I wanted to figure out how the SDRAM access worked, so I messed around with it. I made a change in my fork, and several games seem to run much better. For example, Psycho Fox and Alex Kidd - Lost Stars were both randomly resetting. They appear to be stable now. Feel free to test.

[NegSol]

Great to see your are making progress on this. Also I noticed some random resets in other Arcade cores (e.g. Moon Patrol). Could be completely unrelated but maybe an easy way to investigate sdram issues. Assuming these cores are less complex of course.

[Sorgelig]

Arcade cores don't use SDRAM.
It's possible some arcades may have protection against clones and it wasn't implemented - this is just guess. It's possible the core bug. But you need to understand that arcade cores don't use a common underlying computer core. Every arcade is its own custom system. Moon Patrol for example is the only core with such hardware.

If you think Moon Patrol has bugs, then talk to Darfpga as he already worked on improvements for this arcade.

[Sorgelig]

As mentioned in this thread, I found that the SMS core was having issue with SDRAM access timing:
http://www.atari-forum.com/viewtopic.php?f=117&t=34189#p354216
Testing with the FPGA's built-in RAM seemed to fix issues.
I decided I wanted to figure out how the SDRAM access worked, so I messed around with it. I made a change in my fork, and several games seem to run much better. For example, Psycho Fox and Alex Kidd - Lost Stars were both randomly resetting. They appear to be stable now. Feel free to test.

SDRAM problem is just a part of problems on this core. VDP needs a lot of improvements.
Originally i've thought i could re-use VDP from Genesis, but it turned out Genesis games don't use SMS video mode and thus it's not a part of Genesis core. So, SMS VDP needs to be developed separately.

[Sorgelig]

I suggest to adapt the sdram module from Genesis core as it's synchronous to CPU. In SMS, only CPU can access the ROM, so it's easy to make SDRAM transparent.

[albconde]

Testing greyrogue changes , some games work much better like sagaia, shadow of the beast or Solomon no kagi .

It's a good advance, but this core needs more work

[GreyRogue]

Fixed several initialization issues. Games should boot up a little more consistently now.

While I was in there, I added save support. Tested with Golden Axe Warrior, and appears to work.

Pull request created.

[albconde]

Tested the last changes , some more games now work , like rtype , or Robocop 3.
thans for you work .

[Sorgelig]

Soon i will apply latest framework changes and release the binary.

[PhantombrainM]

Thank you for the new release.
Picture is sometimes not centered and a little bit cutoff by VGA now.

Regards,
PhantombrainM

[NML32]

@PhantombrainM I see the same on my PVM. The picture is shifted a bit too much to the left.

[retrorepair]

Keep in mind this may be in keeping with original hardware though, if you have a real SMS I'd suggest comparing. It could just be that video timings are now accurate.

Video timings are difficult to replicate as they are not very well documented and can only really be replicated by studdying the originals with an oscilloscope.

[Sorgelig]

hsync position will be adjusted in future release.

[albconde]

Tested lots of games now work ok, most of the garbage in graphics is fixed now
Some isues.
addams family : problems in the top of the screen in game
After Burner : boot loader screen
black belt : problems in backgound
Bonanza Bros : boot loader screen
Cool Spot : graphics problems
Ghouls n ghost : boot loader screen , but version (t +por)(p1) work
Global Gladiatos : graphics problems
Golden Axe : : boot loader screen

[thgill]

Noticed something interesting with the latest SMS core release.

HDMi from the MiSTer into my monitor. Audio comes out fine.

However hdmi into my capture device and there is no audio.

I haven’t tested any older SMS cores, but is this a possible bug?

[jayp76]

Just a heads up.
Patched Game Gear games seem to work on the SMS Core, with minor caveats (missing start button).
At the momennt i only teste GG Shinobi. It works fine.
You can find the IPS patches on the SMS Power website.

[Sorgelig]

Just a heads up.
Patched Game Gear games seem to work on the SMS Core, with minor caveats (missing start button).
At the momennt i only teste GG Shinobi. It works fine.
You can find the IPS patches on the SMS Power website.

good idea. will investigate it.

[vanfanel]

This new version of the SMS core has totally changed how things look and SOUND! The new PSG implementation is much better, almost perfect, and graphics garbage is gone.

Some small problems I am seeing:
-Lord of the Sword has blitting problems everywhere: most scenario tiles seem to have a black background.
-The same defect can be seen in WonderBoy 3: The dragon's trap, during the fight with mecha dragon, when you hit the dragon.
-In Castle of Ilusion, there's a small green block on the top-right edge on the screen during the copyright text display.

[the1ross]

Does anyone know if SG-1000 games are compatible with this core or if they'll be added at some point?

[berighteous]

I can't get any games to load. Only boot loader screen. What's the trick? Am I missing something. The files are in my SMS directory.