ST-V Core?

[RiotRay]

Hi!

As the saturn core seems to make good progress, I was wondering if the ST-V core would be possible too.
The ST-V is just a saturn for the arcade after all (with little more ram?).

What do you think?

[FPGA64]

The saturn core almost fills the FPGA. I doubt there is room for additions but who knows

[rubberduck]

If only RAM is the problem i think this should be possible for Dual-SDRAM Configs. Are you sure thats the only difference?

[Chris23235]

The ST-V hardware was identical to the Saturn, it had the same ammount of RAM. The difference was that the ST-V games were stored on ROM-Cartridges instead of CD-ROM. Any potential ST-V core would have to change the CD-ROM interface to the hardware responsible for reading the data from the cartridge.

[pbsk8]

are there exclusive games for st-v?

[AmanoJacu]

are there exclusive games for st-v?

Most of the ST-V games were ported to the saturn, as it was very straight forward to do.

https://www.satakore.com/stv.php

[ExCyber]

The ST-V hardware was identical to the Saturn, it had the same ammount of RAM. The difference was that the ST-V games were stored on ROM-Cartridges instead of CD-ROM. Any potential ST-V core would have to change the CD-ROM interface to the hardware responsible for reading the data from the cartridge.

Based on a combination of my fading memories of Saturn architecture and skimming through MAME code:

ST-V cartridges use the same logical interface as Saturn cartridges. ROM cartridge support is probably a very low-priority task for the Saturn core, though (only two games use them, and both have patches available to use a RAM cartridge instead). Cartridge memory sits on the same bus (SCU "A bus") as the CD block, so I don't think it represents any additional SDRAM throughput beyond variation/configurability of wait states on that bus.

ST-V has an extra I/O chip, presumably because SMPC is simply too sophisticated to speak to a JAMMA cabinet. It doesn't look too bad (basically a handful of counters and GPIO ports?), but it's something that Saturn doesn't have.

Some games have protection chips that would need to be implemented or bypassed.

Batman Forever has an additional DSP board (for compressed speech samples?). This is based on a proper Analog Devices DSP processor, so probably not worth implementing for this one game. This processor family was common on '90s Midway hardware, so maybe that could be leveraged someday.

A few games have non-standard controls (three distinct types of mahjong panel, steering wheel/yoke, some kind of simulated whack-a-mole mechanism?).

MAME has one "ST-V" game that uses its own specific board, a custom cabinet, and the CD interface: Sport Fishing 2. I see several sources on the web claiming that its predecessor, Sports Fishing (yeah, they apparently changed "Sports" to "Sport" for the sequel), was the first arcade game to use Saturn hardware, and did so in combination with LaserDisc. Concrete evidence of this claim is elusive, but I suppose I can't be too dismissive, considering that I live in a timeline where the Pioneer LaserActive exists.

[TLPD-AVW]

ROM cartridge support is probably a very low-priority task for the Saturn core, though (only two games use them, and both have patches available to use a RAM cartridge instead).

Both Ultraman and KoF 95 cartridges have been supported by the Saturn core for a long time now. No need to patch discs to play them.

[ExCyber]

I suppose that's what I get leaving an unbelievably old version of the core in the root of my SD card and not really paying attention.

Just for grins, I loaded an ST-V BIOS on a non-ancient Saturn core, and it does actually display something, but it's a factory test mode that doesn't seem to accept pad input. It probably wants input through the aforementioned I/O chip, and might need an extra settings EEPROM that doesn't exist on Saturn (I missed this in my previous pass through the MAME code) before it will consider itself initialized and actually try to boot a game. At that point, I expect that it would run into the limits of the current cartridge support (ST-V games are unsurprisingly much bigger than the KoF95 and Ultraman cartridges, and the smaller ones seem to also have some non-obvious mirroring).