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FPGA Based Videogame System


kevtris

Interest in an FPGA Videogame System  

682 members have voted

  1. 1. I would pay....

  2. 2. I Would Like Support for...

  3. 3. Games Should Run From...

    • SD Card / USB Memory Sticks
    • Original Cartridges
    • Hopes and Dreams
  4. 4. The Video Inteface Should be...


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I'd argue the Famicom keyboard is a pretty rare accessory in the west. How many collectors even have one? Only a handful of games utilized it, such as Family Basic, and I'm not sure how playable those ROMs are without Japanese...

nintendo_family-computers_1.jpg

 

Cost a pretty penny to ship from Japan, too:

http://ebay.com/sch/i.html?_from=R40&_trksid=p2050601.m570.l1313.TR12.TRC2.A0.H0.Xfamicom.TRS0&_nkw=famicom+keyboard

 

Yes but look at the schematic for it.

 

It's very likely a USB/AT/PS2 to Famicom expansion port would be easy to make, and then the FPGA NT Mini wouldn't need to have that logic in the FPGA to do Family Basic or C64 Basic, Apple II basic, etc.

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Yes but look at the schematic for it.

 

It's very likely a USB/AT/PS2 to Famicom expansion port would be easy to make, and then the FPGA NT Mini wouldn't need to have that logic in the FPGA to do Family Basic or C64 Basic, Apple II basic, etc.

Okay that makes sense. I thought you meant plug in a Famicom keyboard and use it with the classic computer cores. Didn't the NT Mini already have a USB port? Just use that. No adapters. Add a simple hub if you need a mouse or additional HID controllers.

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Okay that makes sense. I thought you meant plug in a Famicom keyboard and use it with the classic computer cores. Didn't the NT Mini already have a USB port? Just use that. No adapters. Add a simple hub if you need a mouse or additional HID controllers.

 

It's a question about saving space on the FPGA. Right now, we don't really know what can be plugged into the USB port as it's only listed as "charging" on the FAQ. If it's only able to charge, then it's not useful. If it it's addressable by the FPGA then it still needs a HID driver.

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It's a question about saving space on the FPGA. Right now, we don't really know what can be plugged into the USB port as it's only listed as "charging" on the FAQ. If it's only able to charge, then it's not useful. If it it's addressable by the FPGA then it still needs a HID driver.

That's a USB A port. Between the power button and power plug.

IMG_4326.jpg

 

USB-A cannot be used for charging or powering the device, only B/C. Or are you referring to the USB-A as an auxillary charge port for 8-bitdo / other controllers? :dunce:

 

How much space do an HID driver take up? What about hubs? Does that require additional driver, say for use with mouse / keyboard?

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That's a USB A port. Between the power button and power plug.

IMG_4326.jpg

 

USB-A cannot be used for charging or powering the device, only B/C. Or are you referring to the USB-A as an auxillary charge port for 8-bitdo / other controllers? :dunce:

 

How much space do an HID driver take up? What about hubs? Does that require additional driver, say for use with mouse / keyboard?

It's meant to be used to change things like the 8bitdo the Mini came with

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That's a USB A port. Between the power button and power plug.

IMG_4326.jpg

 

USB-A cannot be used for charging or powering the device, only B/C. Or are you referring to the USB-A as an auxillary charge port for 8-bitdo / other controllers? :dunce:

 

How much space do an HID driver take up? What about hubs? Does that require additional driver, say for use with mouse / keyboard?

 

No idea off hand, but on some dev boards, it's actually done by the PIC microcontroller, not the FPGA.

http://opencores.org/project,usb_phy, 111 LUT's ( Spartan II XC2S50), (PHY means the physical interface, doesn't include HID driver) I suppose the driver would have to be written to wrap whatever is physically plugged in against the CPU computer core being used.

 

Information out there is kinda sparse as to what it would entail, but I imagine that using the FPGA resources is the more ideal mechanism, but it might not be suitable for the NT Mini, but something plugged into the 15-pin famicom expansion port could be since done on a cheap microcontroller. eg http://www.hobbytronics.co.uk/usb-host-keyboard

 

Anyway, I imagine a Z3K would have more resources to do a computer.

 

Also note on the MiST you can't plug in two mice, as only one is supported. So a two player game that would use it like Lemmings or Marble Madness on the Amiga would be impossible. So it may be desirable to plug in a USB mouse into the controller ports anyway for console/computers that had mice setup that way (like the Amiga and the SNES) but on the NT Mini that's not likely to happen.

 

That kinda leads me to another question that I hadn't thought of till now. I wonder if 8bitdo would make a "classic computer" keyboard ala amiga/c64/atari/etc layout for the NT Mini or Z3K

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The MiST only does a resistor-ladder VGA which is the same thing that VGA on cheaper development boards do. (They're only capable of 4-bits per channel, so they can only do 4096 colors), MiST apparently can do 6-6-6.

But in order to do DVI/HDMI you need to either do it on the FPGA, or you offload it to a framebuffer/scaler HDMI ASIC, which defeats the purpose of trying to eliminate latency.

 

Although the MiST physically has 6bit VGA as input to the DAC, it's able to output 8bit color (and more) by using pulse-width modulation. The technique has been used on the Amiga AGA core, e.g.:

 

As for upscaling, you can eliminate latency if you do simple scandoubling on an FPGA (like with the OSCC) but as soon as you do some conversion of frequency (e.g. to move from 50hz to 60hz) you needs a framebuffer, which will add some amount of lag.

 

The problem of HDMI is that's it's not very tolerant of non-standard frequencies, so you will need to either fudge the original machine clocks to give a clean 50hz/60hz video output (which can cause incompatibilities), or use a framebuffer to "clean" the frequency to something compatible (lag). As far as I know this is inevitable; all projects have to deal with this (MiST + upscaler, FPGA Arcade Replay HDMI, or even Kevtris' with the NT as explained above in this thread).

 

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Hi kevtris, given the XRGBMini is end of life, given the incredible experience you accumulated about HDMI for those old 8 bits, any chance you would try to make a XRGBMini replacement?

 

Wrt HDMI out freq It can do like the original:

mode 1 -> pass thru (if the signal is a little off it's up to the TV to sync on it, no delay/lag but it only works on some TVs and with some consoles)

mode 2 -> via framebuffer (no HDMI issue but stutter when a frame is dropped or duplicated as needed .... so be it)

 

You could probably whip one out in a couple of week-ends, if the case is NOT milled aluminium chances are you can even sell it for far cheaper than the actual XRGB Mini sold for.

Also it can just focus on RGB in, SVideo in, Composite in, and maybe Component, no useless HDMI pass-thru or any JP only cabling, and you could include the LM1881 sync stripper (a <1$ part) that greatly helps (I shoved one in in the XRGBMini Scart to JP21 adapter and solved tons of issues with NeoGeo, SMS, Genny etc...etc... wrt sync signals on those old geezers, no more CSYNC, boosted CSYNC, or any other nonsense to deal with).

 

But I digress.

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FWIW, Micomsoft is supposedly working on a framemeister replacement, though it sounds like it's a couple years out.

Hopefully it'll cost a lot less, I enjoy mine but it was a steep price. Up to the purchase point all my consoles were SVideo modded, if I would have purchased it before I could likely have saved quite some money, time and headache as RGB cables were plentiful and they just work .... oh well, it's an hobby anyway can't complain for what I learnt along the way.

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Hi kevtris, given the XRGBMini is end of life, given the incredible experience you accumulated about HDMI for those old 8 bits, any chance you would try to make a XRGBMini replacement?

 

[...]

Great idea for a new product! Some time ago, kevtris was also asking whether people are interested in the Ultimate NES flashcart. I'm sure kevtris' flashcarts would sell well too...

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Great idea for a new product! Some time ago, kevtris was also asking whether people are interested in the Ultimate NES flashcart. I'm sure kevtris' flashcarts would sell well too...

It's already here, it's called Analogue Nt Mini with Jailbroken FW ;-)

 

Honestly I did wait for Krikzz to fix it's EDN8 mappers to finish sound support where due and fix the horrible FDS off-pitch sounds but almost nothing happened in 2Y. Same thing that happened for FM support for SMS games on MegaED v1 or v2/x7/whatever. Same thing that happened to have fixed KR and some US mapper support for MasterED. Dunno, I like Krikzz works but he's spreading thin and he sells anyway so unless a better competitor comes along he won't do much to rectify.

 

So told rather than a flash cart solution I'd really want for the Z3K to take precedence, as we said limited to 8/16 bits (but the fact that kevtris is mad on the PCE guys doesn't bode well for that particular system to see light of day anytime soon and I don't know how far kevtris is wrt MD/Genny and SNES cores, let alone the NeoGeo [were there any other cart based 16bits? aside INTV I mean])

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Personally I feel like his time is better spent on Nt Mini cores + Zimba 3k work. Unless... can we clone an accurate version of kevtris on an FPGA? :)

He can always make the cart some time after the Z3K release. And of course, it's bit a different target than the Zimba, I suppose. "I'm only playing on a original console" type of thing. Mind you that mappers and software are already there, so it's a matter of reusing this stuff in a clever way.

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Great idea for a new product! Some time ago, kevtris was also asking whether people are interested in the Ultimate NES flashcart. I'm sure kevtris' flashcarts would sell well too...

Holy cow, that's awesome! Ever since the Retrovision had indefinite unavailability. It would be perfect for use with the AVS... :lust:

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It's already here, it's called Analogue Nt Mini with Jailbroken FW ;-)

 

Honestly I did wait for Krikzz to fix it's EDN8 mappers to finish sound support where due and fix the horrible FDS off-pitch sounds but almost nothing happened in 2Y. Same thing that happened for FM support for SMS games on MegaED v1 or v2/x7/whatever. Same thing that happened to have fixed KR and some US mapper support for MasterED. Dunno, I like Krikzz works but he's spreading thin and he sells anyway so unless a better competitor comes along he won't do much to rectify.

 

So told rather than a flash cart solution I'd really want for the Z3K to take precedence, as we said limited to 8/16 bits (but the fact that kevtris is mad on the PCE guys doesn't bode well for that particular system to see light of day anytime soon and I don't know how far kevtris is wrt MD/Genny and SNES cores, let alone the NeoGeo [were there any other cart based 16bits? aside INTV I mean])

I think you've got it wrong.

 

Kevtris has bigger ambitions than fixing competitor's hardware. He's got a vision and has been working on cores for all the systems he's reverse engineered. If he gives his best research away for free in the form of flashcart mappers and plugins, it would devalue his own stuff when he finally develops his all-in-one Zimba3000 solution.

 

That said, the Krikzz Everdrives are amazing pieces of tech as I have many systems, but Krikzz weakness is the expansion audio chips. FME-7 and VRC-6 have been vastly improved since release through third party mappers, but why would Kevtris release his perfect implementation for free when his sound mappers are currently a HiDef NES / NT / NT Mini exclusive?

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Hi kevtris, given the XRGBMini is end of life, given the incredible experience you accumulated about HDMI for those old 8 bits, any chance you would try to make a XRGBMini replacement?

 

Wrt HDMI out freq It can do like the original:

mode 1 -> pass thru (if the signal is a little off it's up to the TV to sync on it, no delay/lag but it only works on some TVs and with some consoles)

mode 2 -> via framebuffer (no HDMI issue but stutter when a frame is dropped or duplicated as needed .... so be it)

 

You could probably whip one out in a couple of week-ends, if the case is NOT milled aluminium chances are you can even sell it for far cheaper than the actual XRGB Mini sold for.

Also it can just focus on RGB in, SVideo in, Composite in, and maybe Component, no useless HDMI pass-thru or any JP only cabling, and you could include the LM1881 sync stripper (a <1$ part) that greatly helps (I shoved one in in the XRGBMini Scart to JP21 adapter and solved tons of issues with NeoGeo, SMS, Genny etc...etc... wrt sync signals on those old geezers, no more CSYNC, boosted CSYNC, or any other nonsense to deal with).

 

But I digress.

I think this would just duplicate the OSSC's efforts. That said, this is essentially what the second FPGA in the Z3K is supposed to be doing. It would not be a big stretch to have a RGB input (either through a VGA or SCART connector) and a HDMI output. Hey maybe the Z3K analog board could also work in reverse and accept an input and send an output over the HDMI.

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I think this would just duplicate the OSSC's efforts. That said, this is essentially what the second FPGA in the Z3K is supposed to be doing. It would not be a big stretch to have a RGB input (either through a VGA or SCART connector) and a HDMI output. Hey maybe the Z3K analog board could also work in reverse and accept an input and send an output over the HDMI.

Remember, Kevtris needed to adjust the timings slightly in order to prevent errors. So an RGB upscaler can't have just timing without breaking compatibility, so a frame buffer is required since the timing of the input cannot be adjusted. Then it becomes a laggy upscaler like any other device. And native digital from source to output is infinitely better than an analog-to-digital video conversion in the chain. It isn't like audio where analog sound can be assigned any arbitrary sample rate.

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