Atari Jaguar Core

[pepito]

So existing to have this CORE ready!
and Cdrom support will be welcomed.

[VegaVegas]

Can anyone report how Alien vs Predator works currently??

[Chris23235]

Can anyone report how Alien vs Predator works currently??

I saw videos of this game running on the core, but couldn't get it to work myself, regardless of the version I tried.

[VegaVegas]

I saw videos of this game running on the core, but couldn't get it to work myself, regardless of the version I tried.

OK so even if it were supposed to be working then how would it look?? Where is any example showcase video??

[Chris23235]

I saw videos of this game running on the core, but couldn't get it to work myself, regardless of the version I tried.

OK so even if it were supposed to be working then how would it look?? Where is any example showcase video??

Look here:

https://youtu.be/u6tPsCS9B-c?t=766

[dmckean]

Can anyone report how Alien vs Predator works currently??

This core has very little implemented besides the 68000 CPU. I think it runs five games and it hasn't been worked on in two years now.

[Chris23235]

Can anyone report how Alien vs Predator works currently??

This core has very little implemented besides the 68000 CPU. I think it runs five games and it hasn't been worked on in two years now.

The core has the complete Jaguar hardware implemented.

[Kitrinx]

Can anyone report how Alien vs Predator works currently??

This core has very little implemented besides the 68000 CPU. I think it runs five games and it hasn't been worked on in two years now.

The Jaguar core has the 68000, the OS rom, the cart bus, the dram bus, and Tom and Jerry both fully implemented by converting atari's own netlists.

The issue with the core is the real hardware used a very wide and relatively fast dram bus, that seems to require dual ram to achieve on mister, and secondly that it has bugs that are difficult to identify. Because the two largest chips in the device (Tom & Jerry) are both generated, they are very difficult for humans to read, and simply learning how they work well enough to debug the DMA and memory timing issues is challenging.

[KremlingKuthroat19]

Can anyone report how Alien vs Predator works currently??

This core has very little implemented besides the 68000 CPU. I think it runs five games and it hasn't been worked on in two years now.

The Jaguar core has the 68000, the OS rom, the cart bus, the dram bus, and Tom and Jerry both fully implemented by converting atari's own netlists.

The issue with the core is the real hardware used a very wide and relatively fast dram bus, that seems to require dual ram to achieve on mister, and secondly that it has bugs that are difficult to identify. Because the two largest chips in the device (Tom & Jerry) are both generated, they are very difficult for humans to read, and simply learning how they work well enough to debug the DMA and memory timing issues is challenging.

Thanks for the detailed writeup! So it seems that Jaguar will work on MiSTer with dual ram exclusively. That's fine with me and it's good to know that Porkchop created a Dual Ram configuration. Maybe he created that build knowing this is the case for the Jaguar core.

Since there's no additional hardware in the CD drive, would the Jaguar CD also fit on a dual ram setup?

[Kitrinx]

This core has very little implemented besides the 68000 CPU. I think it runs five games and it hasn't been worked on in two years now.

The Jaguar core has the 68000, the OS rom, the cart bus, the dram bus, and Tom and Jerry both fully implemented by converting atari's own netlists.

The issue with the core is the real hardware used a very wide and relatively fast dram bus, that seems to require dual ram to achieve on mister, and secondly that it has bugs that are difficult to identify. Because the two largest chips in the device (Tom & Jerry) are both generated, they are very difficult for humans to read, and simply learning how they work well enough to debug the DMA and memory timing issues is challenging.

Thanks for the detailed writeup! So it seems that Jaguar will work on MiSTer with dual ram exclusively. That's fine with me and it's good to know that Porkchop created a Dual Ram configuration. Maybe he created that build knowing this is the case for the Jaguar core.

Since there's no additional hardware in the CD drive, would the Jaguar CD also fit on a dual ram setup?

The CDROM drive uses a proprietary ASIC called "Butch" which I know very little about, and is completely un-emulated to the best of my knowledge. No idea how much space it would take.

[frankschwab]

Does anyone know if the CDROM emulation on the Jaguar GameDrive was implemented in software or FPGA?

[Chris23235]

Does anyone know if the CDROM emulation on the Jaguar GameDrive was implemented in software or FPGA?

As the Gamedrive states that "many" CD games work and it only works on a Jaguar without CD-Addon my guess is they take a completely unique approach different from how the original hardware acted.

[german_user]

I don't think there's any point in debating a CD feature as long as the core is in such a state that almost nothing is running. I'm also not sure if anyone dares to take on the project after all these years.

[KremlingKuthroat19]

I don't think there's any point in debating a CD feature as long as the core is in such a state that almost nothing is running. I'm also not sure if anyone dares to take on the project after all these years.

I wouldn't say almost nothing is running. Afaik, many games are running, they're just not stable enough to be played. This core will need a lot of attention to get it to the point where it'll be good enough to be made public. This core is further along than any other non-official core outside of the Saturn, PS1 and Jotego's cores, if I'm correct. No one should hold their breath on when the core will be finished, but the core's in a great place all things considered.

[Kitrinx]

I don't think there's any point in debating a CD feature as long as the core is in such a state that almost nothing is running. I'm also not sure if anyone dares to take on the project after all these years.

I wouldn't say almost nothing is running. Afaik, many games are running, they're just not stable enough to be played. This core will need a lot of attention to get it to the point where it'll be good enough to be made public. This core is further along than any other non-official core outside of the Saturn, PS1 and Jotego's cores, if I'm correct. No one should hold their breath on when the core will be finished, but the core's in a great place all things considered.

most games load, and run for some period of time. Eventually the DMA deadlocks and the game halts. Only a few dont load at all. Tom & Jerry are taking up too much of the bus time currently so the 68000 is starved by about 50%. Depending on which of the processors the game was relying on to run (Jaguar was goofy and you could choose to use any of the three) this will impact the execution speed of games as well.

[atrac17]

The Atari Jaguar will be implemented by jotego this year. Not solely off netlists from Atari (nobody knows the version of Tom & Jerry - i.e. final version) and tourlus' core that electronash started fleshing out and porting to MiSTerFPGA.

[akeley]

Well, now. When Jotego says something, it's best to pay attention. Having a Jaguar core would be another big coup for MiSTer, alongside Saturn, ticking off two of the infamous not-so-great-in-emulation trifecta and leaving just N64 as the last frontier.

[FPGA64]

Jaguar core is already on Mister. It has a few issues but its already here

[akeley]

"A few issues" is a rather optimistic way to put it. If it was true we'd be all happily playing Jag games, and Jotego wouldn't bother with "fresh implementation".

[FPGA64]

Was playing the experimental Dual ram version last night. It played the games with issues. The current implementation is direct from the netlists used by Atari.

[akeley]

Seems we have a somewhat different definition of "issues", at least in the context of my first post here. For me a core on which games only "run for some period of time" does not count as an usable one (no matter how impressive the coding effort behind it is).

[Moondandy]

The dual ram Jaguar board is in a good WIP state, quite a lot of games seem to run fine now based on my testing yesterday. It's just going to take time, and hopefully JT announcing he wants to make his own core is the impetus for people to work on the current core and get it working fully and not the opposite, with people being put off now.

Based on the progress on NGPC, which would have been in Main within a matter of weeks if Robert had worked on it instead of JT, there won't be a JT Jaguar core this year. Even once it is released it will probably stay in beta behind a pay wall for another year. So maybe in 2024 there would be an unofficial core not behind a paywall. I think the other devs can get an official core out long before that, especially if Rysha is looking at it.

I imagine there will be a good few patreons scratching their head why CPS3 and PGM aren't on this list but Jaguar is.

[Kitrinx]

The current core may seem like it's in rough shape because it's so easy to make the object processor stall and crash, but a lot of things are going pretty right. I do think just spending a little dedicated time to get familiar with how the ASICs were made and clean up the TLW signal issues, which are almost certainly surrounding the problems, can get it into a very good state at this point.

[Moondandy]

Thanks for working on the Jaguar core, and hopefully you aren't put off by this JT announcement.

[Moondandy]

What would it take to get the information needed to emulate the Jag CD? Would it require getting a Butch chip to someone like Furtek to decap and trace, or get working hardware into someone's hands who can probe into it?

[KremlingKuthroat19]

Yeah with all due respect to Jotego who's an absolute FPGA legend, I'm not a fan of his calling "dibs" on console cores and then putting them and other cores on the backburner. Who knows if NGPC will even release this year. The progress is quite slow since the CPU isn't even complete yet and he's been working on that for the last quarter.

I'm trying to say this without being too disrespectful, but I'd much rather this current implementation of the Jag get completed since it's so far along and I don't want this work to be wasted if Jotego's working on it

[Moondandy]

Have had a lot of long, dull meetings today, so done a smoke test on the library (minus a few games that weren't in my pack I will need to track down). Decent coverage. 30 games playable, 14 you can't get into play. Generally distorted sound throughout, and several games have a belt of corrupt pixels in the bottom half of the screen, but that aside very playable in these games from what I have seen. The core has really come together, good effort Rysha!

If anyone wants to do some deeper testing just request edit access or ping me your email.
https://docs.google.com/spreadsheets/d/ ... sp=sharing

[german_user]

Do I understand correctly that 3 people work on the core, or does Rysha use Ash's base?

30 games can be started, that really wouldn't be that bad. There's actually less than 100 if I remember correctly.

[Moondandy]

There are only 50 official games in total and 30 were playable for a couple of minutes fine, save a few which had a similar graphical issues. There are likely other issues burries in there I didn't come across, but that would require deeper testing. I will try find the games I don't have tomorrow and try those as well. Great progress over the the version Ash last added to GitHub a few years back.

[dmckean]

Do I understand correctly that 3 people work on the core, or does Rysha use Ash's base?

Torlus wrote the core many years ago now using the netlist files from Atari. ElectronAsh ported it to MiSTer and attempted to make it run. Rysha (Kitrinx) is now also having a go at making it run. Ash's attempt had bandwidth issues so she implemented dual SDRAM to help alleviate that some. It still has a number of issues. The way the netlists were brought into verilog makes the code extremely difficult to understand.

There were only ever 50 official games released for the Jaguar. So having 30 run isn't too shabby.