- Thread starter Yippikaye
- Start date
ShootTheCore
Legendary
Last I checked, talking about Cave Multis is discouraged on these forums since the company in question is litigious and very protective of their IP.
That said, there is a 68000 Cave FPGA core nearing completion on the MiSTer project, and there's PGM boards for sale on these forums that can allow you to play the three PGM Cave games. So there are options...
That said, there is a 68000 Cave FPGA core nearing completion on the MiSTer project, and there's PGM boards for sale on these forums that can allow you to play the three PGM Cave games. So there are options...
it is mainly the 68000 series of cave games i am interested in...
hence i may have to bite the bullet with a mister setup,
but skill/effort involved to get a working mister just seems all too much for my level of knowledge.
hence i may have to bite the bullet with a mister setup,
but skill/effort involved to get a working mister just seems all too much for my level of knowledge.
No pain. No gain. This forum is your friend. If you run into any hiccups setting it up, post in the Mister thread or start a new one. I’m sure people will obligingly help.
No way, you can do this. It looks complicated at first, and there's a lot to take in, but it's really not bad.
regarding the mister another major reason for me not getting one is because all the consoles that intrest me i already own (and with sd carts most of the games too)
Hence while i am amazed with the mister project and try to stay informed;
i think (know) that a completed cave core may just be the tipping point for me to invest my time and money and get one.
And to get back on topic; it just maybe the cave multi done by stealth...
Hence while i am amazed with the mister project and try to stay informed;
i think (know) that a completed cave core may just be the tipping point for me to invest my time and money and get one.
And to get back on topic; it just maybe the cave multi done by stealth...
Hatsune Mike
Champion
Just FYI by its design the Atlus 68000 ( Cave ) FPGA project is either going to have added latency, or have misalignment between background and sprites. It is a flaw that is understandable given the development circumstances and limited number of memory buses present on the mister and most FPGA dev kits, so it doesn't reflect poorly on the developer (please stop harassing him about it). That said, it is a way that an inaccuracy is present that isn't super trivial to overcome here. Furthermore, I believe the memory access speed penalties are not simulated, and also there are stalls because of the use of a single memory controller.
How much added latency are we talking about? According to the dev that PCB has a framebuffer, so even if it adds an extra frame over and above that, for a free alternative to MAME with proper slowdowns we cannot expect more.
Hatsune Mike
Champion
"Framebuffer" as a term itself is not a problematic thing, in general. The original Atlus 68000 hardware used in DDP has a framebuffer for the sprites. However, his entire system uses a framebuffer, including the backgrounds, and not just the sprites. As designed, based on his paper, it sounds to me like the backgrounds will be delayed one frame compared to original hardware. The impact is minimal, but it means the background will appear to be shifted vertically a little bit, and things like the disappearance of the stage 3 sky ships will happen one frame out of sync. This can be remedied by adding an additional frame of latency to the sprite layer.
The original DDP hardware's sprites are effectively delayed by two frames: the sprite description list is double-buffered, and the sprite framebuffer is double buffered. In contrast, the background layout data is not double buffered, and is simply updated during vblank. Then, during active display, pixel data is generated on the fly through repetitive fetches from background VRAM and background character memory. The Atlus hardware Cave used is so simple, that one IC covers one layer. More backgrounds were added by simply adding more background ICs, and totally separate memory buses. That's two buses per background layer! (even though the VRAM is switched to the 68000 CPU bus during access, it is mastered independently by the background IC during active display).
To implement these old systems accurately, imo, we should be creating verilog models of each individual IC. I believe simplifications in order to facilitate connections with other ICs, or to reduce memory buses, should be done by helper components or wrappers.
Again, minimal problems, but it goes against the grain for something that is being sold with promises of higher accuracy. it sounds like a very simple problem, but to do it "right" the rabbit hole can go a bit deeper than expected.
The original DDP hardware's sprites are effectively delayed by two frames: the sprite description list is double-buffered, and the sprite framebuffer is double buffered. In contrast, the background layout data is not double buffered, and is simply updated during vblank. Then, during active display, pixel data is generated on the fly through repetitive fetches from background VRAM and background character memory. The Atlus hardware Cave used is so simple, that one IC covers one layer. More backgrounds were added by simply adding more background ICs, and totally separate memory buses. That's two buses per background layer! (even though the VRAM is switched to the 68000 CPU bus during access, it is mastered independently by the background IC during active display).
To implement these old systems accurately, imo, we should be creating verilog models of each individual IC. I believe simplifications in order to facilitate connections with other ICs, or to reduce memory buses, should be done by helper components or wrappers.
Again, minimal problems, but it goes against the grain for something that is being sold with promises of higher accuracy. it sounds like a very simple problem, but to do it "right" the rabbit hole can go a bit deeper than expected.
If I read that correctly, it can be accurate except backgrounds will be off by one frame (which seems like basically a non-issue in practice?).
That sure sounds a lot better than imposing extra delay due to more buffering.
That sure sounds a lot better than imposing extra delay due to more buffering.
Hatsune Mike
Champion
The backgrounds will be positioned incorrectly as a result, whenever there is scrolling.
It's not a big issue in practice, but since the fanaticism around the Mister has a lot to do with supposed accuracy, it would be a disappointing conclusion for a core.
It will look extra dumb in ESP Ra De, on stage 4, with the large train on the right side of the screen. Perhaps the average mister owner will never reach this stage, so it is a non-issue.
I hardly believe a small company like Cave (that barely care about their IP's anymore) have the muscles to go after a small team of hobbyists on the other side of the world. Especially if said team is working quietly in the dark until completion.
There are already multiple Cave games on Pandora boxes and conversions floating around without any problems. You give Cave too much credit.
Now, ganging up on a domestic arcade operator that would be running a CV1K multi in their cabs, that's a whole different story.
Cave obviously care about their IP. ESP Ra. De. is set for console release next month, and they’ve finally updated their iOS ports to work on newer versions. Ketsui came out last year for console and I’m pretty sure we’ll see more of the same in the future.
The hype around their elite standing with shmup enthusiasts, prices and scarcity for Cave PCBs would still be fueling their appeal as a company. Damaging that by creating a product that cheapens the worth of their legacy would be a blow to them that I can’t see them taking too lightly.
I’m 100% certain their legal team would not be kind to anyone who profited on a product playing their catalog on original hardware. Pretty sure @Darksoft has requested not to discuss it on the forums numerous times also.
Finally, the majority of their catalog is available on Xbox 360 running as close to perfect as you could get. Tee that up with a Jammaizer! and you’re good to go. Do yourself a favor and just indulge in a DoDonPachi PCB though as the port on Instant Brain is trash
Meh, buying a porting service 20 years later is hardly caring. The reason is that they're doing poor business with the mobile phone operations and they have left their core business area. Their profit margin is tanking hard the last few years.
Yes, they have requested us to not discuss it. Why, because Cave told them we are not allowed to discuss it in a forum for exactly that purpose?
No. I disagree, shooting is a niche genre in a niche hobby. They don't care what we few think. Their legacy comes with the profit the operators make (or made) in the arcades and their business relationship. And as of now, Cave is not making the profit they need.
Yes, they have requested us to not discuss it. Why, because Cave told them we are not allowed to discuss it in a forum for exactly that purpose?
1. The guy who runs the forum has asked us not to discuss it. I'm a polite guest (mostly) and abide by rules set out in the places I visit. It's called basic manners.
2. The reasons why it's not a good idea have been stated numerous times, by numerous people in this thread and in others. You can choose to think otherwise and that's fine too. 'Nuff said.
