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SainT

Upcoming Jaguar Game Drive Cartridge

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Here's a little update on the JagSD and also the upcoming NeoGeo Pocket SD as well...

 

 

I've been working on the NGPC flash as a stepping stone to the JagSD, as all the hardware (in some form) from the NGPC cart and programmer will be used in JagSD.

 

Apologies that anything I hold constantly wiggles about, genetics can be a twat. But amazingly I can manage to solder fine pitch SMT devices with that hand tremor, though... :)

awesome stuff, id love to beta test if you aint already got someone lined up :)

 

im going to have to buy a neo geo portable now :)

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GadgetUK has kindly offered his help, so I'll start with him initially as he's been of great help on the Lynx cart as well. But once things are working I'll be after another 2-3 people or something just to give it a good hammering. :)

Edited by SainT
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GadgetUK has kindly offered his help, so I'll start with him initially as he's been of great help on the Lynx SD as well. But once things are working I'll be after another 2-3 people or something just to give it a good hammering. :)

I'm always happy to help beta test hardware.

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Really looking forward to this one! Great vids on YouTube and I'll definitely be buying when their available.

 

Sent from my Nexus 6P using Tapatalk

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And I'm just down the road from you, so I can help too. I'd recommend OMF to help too he's good at finding stuff others miss.

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Here's a little update on the JagSD and also the upcoming NeoGeo Pocket SD as well...

 

 

I've been working on the NGPC flash as a stepping stone to the JagSD, as all the hardware (in some form) from the NGPC cart and programmer will be used in JagSD.

 

 

Very cool to hear about the NGPC flash drive. I currently own a Flash Masta. It works fine, but is limited to only store two games at a time (or one large game) since it doesn't have a slot for an SD card.

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I'm guessing you'll need an active jag dev team that could help you ** cough** cj

 

Yes, he's already on my radar... ;)

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Here's a little update on the JagSD and also the upcoming NeoGeo Pocket SD as well...

 

 

I've been working on the NGPC flash as a stepping stone to the JagSD, as all the hardware (in some form) from the NGPC cart and programmer will be used in JagSD.

 

Apologies that anything I hold constantly wiggles about, genetics can be a twat. But amazingly I can manage to solder fine pitch SMT devices with that hand tremor, though... :)

Ha, I put in Exxos' PSU and put together the Fast TOS switcher he sells into my 1040STe on Sunday. Dropped the soldering iron twice, once in my lap and once on the floor...

 

Never solder naked... granted I wasn't, it's just that really would have sucked. I do have a burn mark on my pants though..

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Here's a little update on the JagSD and also the upcoming NeoGeo Pocket SD as well...

 

 

I've been working on the NGPC flash as a stepping stone to the JagSD, as all the hardware (in some form) from the NGPC cart and programmer will be used in JagSD.

 

Apologies that anything I hold constantly wiggles about, genetics can be a twat. But amazingly I can manage to solder fine pitch SMT devices with that hand tremor, though... :)

 

This is a good update. I see both are coming along now. Both will be great.

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Thanks for the support everyone, always keeps the motivation up seeing people are excited about the prospect of these things! :)

 

I'm going to do my best to setup some kind of pre-order / shop type thing on retrohq.co.uk to make things a bit easier than doing it through a thread. I did have a look into it sometime last year, but I need some more work put into it yet... :)

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Who are these people?

 

If other people can see them, they are real. Otherwise, it's just in your head.

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As a developer, how will I be able to read data from SD card to JAG's main RAM at runtime?

How much memory will be addressable this way? I understand that CDRom - based games will be able to read those ~700 MB, but will there be a way for a programmer to page/swap in data from, say, 2GB SD card?

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I wonder if it's feasible for it to emulate both the Alpine and the skunkboard.

 

In what way "emulate"? I intend to have debugging capabilities (with a header which can be connected to the Jag PCB via a ribbon cable, like the Alpine), but I'm not sure what capabilities of the skunkboard would be wanted? Please let me know what you mean in more detail so I can consider what I can do.

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On 1/22/2017 at 3:27 AM, VladR said:

As a developer, how will I be able to read data from SD card to JAG's main RAM at runtime?

How much memory will be addressable this way? I understand that CDRom - based games will be able to read those ~700 MB, but will there be a way for a programmer to page/swap in data from, say, 2GB SD card?

 

I will most likely be doing the memory card interface much like how Atari handled the CD ROM interface. You request a block (or series of) from the memory card through some memory mapped registers, then stream the data back in over the I2S bus. This allows the best the Jag can offer in terms of DMA streaming.

 

I may also be doing some form of audio decompression on the micro on the card as well, such that you could request to play an MP3 and have this decompress on the card and stream over to the Jag as raw PCM data. So this would make Jag CD images smaller and also allow more flexibility for audio in any further games for the Jag.

 

The access to the memory card would be native as well, so you could access as much data as the card contains, it wont be limited.

Edited by SainT
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Thanks a lot for your answers. I have couple more technical questions:

 

 

I will most likely be doing the SD card interface much like how Atari handled the CD ROM interface. You request a block (or series of) from the SD card through some memory mapped registers, then stream the data back in over the I2S bus. This allows the best the Jag can offer in terms of DMA streaming.

OK, so the way I read it, is that the cart's microcontroller will be monitoring some memory area in jag's 2 MB address space at a specific range of addresses (sort of like memory ports), so then a developer can directly control the functionality of the SD cart (be it memory transfer, Ethernet, or whatever else functionality it will have) at any point at run-time.

 

So, this is how a memory transfer command might look like ?

; Transfer details
DESTINATION_ADDRESS_JAG .equ $40000
SOURCE_ADDRESS_SD       .equ $1F0300
BUFFER_LENGTH           .equ $1000

; SD-cart Registers 
SD_SRC       .equ $XYZ1
SD_DST       .equ $XYZ2
SD_LEN       .equ $XYZ5
SD_CMD       .equ $XYZ3
SD_STATUS    .equ $XYZ4
SD_TRANSFER  .equ $17

; Code to request the transfer
move.l #DESTINATION_ADDRESS_JAG, SD_DST
move.l #SOURCE_ADDRESS_SD, SD_SRC
move.l #BUFFER_LENGTH, SD_LEN
move.l #SD_TRANSFER, SD_CMD

I may also be doing some form of audio decompression on the micro on the card as well, such that you could request to play an MP3 and have this decompress on the card and stream over to the Jag as raw PCM data. So this would make Jag CD images smaller and also allow more flexibility for audio in any further games for the Jag SD.

I don't understand the point of saving couple KBs on an basically unlimited SD card, where 1 TB costs 3 cents, as it's still going to have to be raw&uncompressed in jag's very small 2 MB memory, so what am I missing here ?

Can you please leave this feature for after the launch ?

 

 

The access to the SD would be native as well, so you could access as much data as the card contains, it wont be limited.

Since 2^32 is only 4 GB, it's impossible to address more than that at a byte resolution. Which one of the following workarounds are you going for ?

1. Minimum Sector/Alignment size (e.g. using multiplies of 2,4,8,16,32,64,.....1,024+ KB)

2. 64-bit addressing

 

 

This is obviously a very long shot, and it's something for you to think about, but is there any possibility I could temporarily borrow a partially working (just the memory transfers working) prototype (I'd pay manufacturing and shipping costs) and create some prototype that would be using the additional SD card memory (I'd release the demo for free download) ? I've created run-time streaming endless terrain components in past (that work with only small terrain subset in memory), but stream everything else from the filesystem, where the terrain size is limited only by the space on the harddrive. E.g. you have a 1kmx1km terrain chunk in memory, but as you move through world, the engine is streaming the other chunks from the filesystem (so it does not matter if the world is 10x10 km or 1000x1000 km). I'm using WorldMachine for terrain generation, btw.

 

I understand if you wouldn't want to do that, but I figured I'd ask.

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If you want to see how data transfer might work from the memory card, look at the source code for accessing the Jaguar CD ROM via Butch. As I mentioned before, it will work in a very similar fashion.

 

Any features like the MP3 decoding would likely come after initial release, yes -- not essential but nice to have. And as the microcontroller and CPLD will be updatable via software, anything can be done via updates.

 

Memory cards are accessed in sectors -- larger ones anyway, the original spec used byte addressing as I remember, and hence was limited to 4GB. So that gives something like 2TB. I cant remember if block size varies at all from 512 bytes, but either way 2tb isnt going to be limitation.

 

Actual hardware is a little way off yet, I'll consider what's happening when I have some units to give out. My priority will be making sure of compatibility with all commercial titles initially, but I welcome discussion of any features people may want so I can make sure the hardware is built with as much flexibility as possible. There is a fair bit of logic space on the CPLD at the moment, so additional functionality is possible...

Edited by SainT
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