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SainT

Upcoming Jaguar SD Cartridge

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Oh, and something else which is very cool, I have a YM2149 core which I should be able to include too. I've not checked on how much space it takes up on the CPLD, but I think it should be fine. So CJ's ST ports could include sound.... :D

 

The audio out will just be a couple of registers, so they can just be output directly via the Jag DSP.

 

And I could also include a planar to chunky register too. Write your 4 planes, read back your 16 pixels in chunky 4bpp or 8bpp or whatever.

 

 

Very nice...this keeps getting better and better. Nice work man.

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Not an emulator as such... as CJ has said before, there's a lot of work goes into making ST stuff work on the Jag. Although there's no reason not to get EmuTOS running... :)

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Nice features :)

 

Don't think I'd use them though, as then they wouldn't work without the flash cart.

 

Surely everyone will have one, though? Lol. :grin:

 

Though getting YM sound support in for the JagSD should be pretty simple. I've not tried (yet), but I cant imagine there are many places to patch in a standard ST music driver for the $ffff88xx writes. And it will literally be swapping this for a write in the ASIC address space and a straight move two words from the ASIC to the DSP audio out at whatever frequency you like.

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Surely everyone will have one, though? Lol. :grin:

 

Though getting YM sound support in for the JagSD should be pretty simple. I've not tried (yet), but I cant imagine there are many places to patch in a standard ST music driver for the $ffff88xx writes. And it will literally be swapping this for a write in the ASIC address space and a straight move two words from the ASIC to the DSP audio out at whatever frequency you like.

Just let it get music into the VLM and I'll be a happy camper.

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Just let it get music into the VLM and I'll be a happy camper.

I can dream of a DLNA player that uses a SDcard with Wifi to read off a Plex server, right?

 

(sorry for the off-topic) I wish Polybius had a hidden VLM mode...

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Finally! After lots of pain getting the memory controller working properly in the case where the chip select and output / write enables were not strobed in-between accesses (just the address changes), I've got a bloody game running! :-o :D :lust: :rolling:

 

I can't explain how gratifying it is to see the bugger working as the last couple of days have been rather painful -- all the time feeling so close yet so far. I was wondering if it was even possible with my multiplexed bus approach, as during a read you need to leave the bus ouputting valid data until its latched on the console and hence you cant check the address for change. Thankfully there are a couple of cycles in-between reads where I can switch and check the address. It's very tight, but it's all synced perfectly to the Jag's 26mhz main bus through the CPU clock output on the cart (13mhz), then through a PLL to up it to 26Mhz. I've not tried other cycle access timings yet (it's on the default of 10), but as all commercial releases are at 10 cycles, it wont be an issue if they don't work.

 

The game itself is read from the SD card on the cart. I've got some very unoptimised and crude code for transferring the data from the SD card into a buffer on the microcontroller, then to a register on the cart which can be read over SPI from the Jaguar. Even with this shit setup its reading the 2mb game in about 14 seconds. And this is doing things like checking the transfer is finished after EVERY byte. So there's massive improvements to be had here, although I'm still limited to about 12mbit due to limitations of the microcontroller.

 

After a couple of days of working completely non-stop, I can take a break now!! :D

 

I'll post up a video tomorrow.

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I don't understand the techincal side very well, but well done. You must be v.pleased. 14secs is pretty good as a first stab. I guess that is the time to swap between carts/images. If you don't change the cart/image but power cycle the Jag, loading is instant?

Can't wait to see the video.

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I don't understand the techincal side very well, but well done. You must be v.pleased. 14secs is pretty good as a first stab. I guess that is the time to swap between carts/images. If you don't change the cart/image but power cycle the Jag, loading is instant?

Can't wait to see the video.

 

No, you have to load a cart in each time you boot. The ROM emulation is via SDRAM (the same sort of stuff you have in your PC), so it's not persistent at all between power cycles. Its not even persistent if you don't constantly refresh it during use! Load time though, when optimised at a hardware and software level, should only be a few seconds. At the moment the code is shockingly crap, I'm surprised its as quick as it is! :)

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Best news for Jag owners in a long while, especially for those who just want to play games that are insanely expensive or unavailable.

Thanks for your considerable efforts! Looking forward to the finished product! :)

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There's a fair bit of flexibility in there to add additional support for emulators / ports etc... if people wanted to go that route. Additional sound chips or data conversion are a damn site easier to do in hardware. The CPLD on the cart is currently only about 36% full, and that's the smallest chip with the functionality I need, so I may as well add some additional features in there. As there are a lot of open source cores for sound etc, it requires very little effort to add them in.

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That' a great piece of work, truly amazing. I can't wait to get one. :-)

 

I've got one question and maybe I've overread it but will it have a reset-button to get back to the main menu on the SD?

 

Or, even better, the possibility to have an in-game reset by using the Jag Contoller?

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That' a great piece of work, truly amazing. I can't wait to get one. :-)

 

I've got one question and maybe I've overread it but will it have a reset-button to get back to the main menu on the SD?

 

Or, even better, the possibility to have an in-game reset by using the Jag Contoller?

 

That's something I've not talked about -- I could have a reset button on the cart, although that doesn't help much as you could just power on and off if you have to be able to reach the console. However, resetting from the controller, which actually is useful, looks like its possible. The controllers are on the external side of the bus, which is connected to the cartridge at all times, so I can actually detect when the Jaguar is reading or writing to the controller port and actually intercept this. So I should be able to detect a keypress combination and reset the console.

 

There's potentially the possibility of some kind of cheat type menu as well, but only if you modify the Jaguar and install a cable which runs out to the cartridge. This is actually the developer connector on the Jaguar PCB and allows for non-maskable interrupts such that any program can be broken into.

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Doesn't the Jag already have the reset function from the controller? Seemed to me it was a hard wired thing and worked in every game, though I also recall a game or two that seemed to only go back to the game's menu rather than doing a full reset of the Jag. Am I wrong about that?

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Doesn't the Jag already have the reset function from the controller? Seemed to me it was a hard wired thing and worked in every game, though I also recall a game or two that seemed to only go back to the game's menu rather than doing a full reset of the Jag. Am I wrong about that?

 

You're thinking of *#, this just takes you back to the title screen / main menu. Not a full reset, and wouldn't take you to the SD menu.

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