FPGA Based Videogame System

[Videodr0me]

no, the video is all generated internally to the FPGA. There's several PLLs on the FPGA itself, and I am using those to generate the various clocks. There's around 22 clock domains on the design as it stands. The problem is I would need some non-integer N/M ratio to get the right clock for the HDMI stuff from the 21.47Mhz domain. Right now video gets a clock that varies depending on video mode. i.e. it's 148.5Mhz in 1080p mode. There's no easy way to lock the two PLLs together (the one generating 21.47Mhz and the 148.5Mhz one) in the proper ratio to offer 60.09 hdmi.

 

The video always runs at 60.00 fps and it will cause cycle stealing on the snes side to make it stay in synch with the hdmi for the zero delay mode. If you run full/single buffered, the cycle stealing is turned off and is allowed to free run.

 

So, this means that - and please correct me if i am wrong, as there are probably a myriad of things i am simplifying away:

 

a) the SNES is always run at original clock speed in non-zero delay modes

b) Even In zero delay mode the SNES is still running at original clock, but is stopped for a number of cycles after each scanline in order for the hdmi readout of that line to catch up.

 

but does that not lead to problems if for example a sound sample is playing and ending right before the clock is stopped, couldnt this (very small) delay lead to discontinuities (clicks, popps)?

 

Does this have something to do with the "Earthworm Jim (PAL)" audio problems in zero-delay mode?

 

I am an advocate for a special 60.09 mode - and I believe (from my own testing) that your worries about hitting that 148.5 Mhz exactly are maybe a little to strict. And even with a 148.5 Mhz Master HDMI Clock there are ways to get to that 60.09 (or even to the the exact frequency). Just some ideas, you probably already thought about:

 

1) Use an integer multiplier of 7 * 21,47 =~150,29 HDMI Clock - I beleive that 90%+ of TVs would handle that.

2) Keep the 148.5Mhz HDMI clock, but shorten each frame by two or three lines of vsync (in the frame sent over hdmi, not in the snes) and/or adjust hsync a little. With a little linear programming one should be able to find a combination that hits 60.09 and is still TV compatible

3) Do not use cycle stealing, but just change the 21,47 clock to run at 148,5 / 7 = ~21,214.(If all fails and we must live with 60.00Hz - at least this would prevent cycle stealing)

4) use any of the tricks above in combination to get closer to 60,09, in order to reduce cylce stealing (if it cannot be avoided altogether)

 

In all cases such options should come with a disclaimer and a hot-key on boot-up to restore "normal" hdmi behavior. I find the Super NT such a great system almost living up to all the claims made by analogue, but without a tearing and frame drop free hdmi mode at original speed it is not really 100%. But i am pretty optimistic that a way will be found and implemented via firmware update, if not now maybe after the dust has settled a bit.

 

Apart from that I found the following incompabilities:

 

- JP Samurai Spirits crashes after the initial Logo, sometimes the cherry-blossom animation runs for half a second before the screen blanks.

- JP Accele Brid crashes during gameplay - music continues playing but game freezes.

- JP Bakukyuu Renpatsu!! Super B-Damon lets you only use hotkeys during fades to black. As these become very seldom in game, hot-keys cease to work for long periods of time

- JP Zootoo Mahjong (my favourite Mahjong) no hot-keys at all

- Pac-Man (A&S NES Hack) graphics corruption

Edited February 19, 2018 by Videodr0me

[bikerspade]

Mine randomly turns on and off, when it's connected to the TV USB Port while the TV is off. Seems like the TV power cycles the USB Ports from time to time... It's fine when the TV is on, but I also don't like that the TV turns the SuperNt on when I just want to watch a movie or something. Enabling the TV's USB-Charge function doesn't change that, although it's supposed to keep the USB ports powered all the time. Often I see the SuperNt's power LED lit when the TV isn't even on. So for now i'm using the USB 3.0 port on my Xbox One which doesn't power cycle all the time...

Do you have a Chromecast, and if so, does the same symptom happen when you are using it while powered by the TV's USB?

[Fafner]

Game collecting has gone from a dorky hobby into something driven by people who think of it as an investment to eventually cash in.

 

Thats why Im hoping the collecting bubble bursts!

Id like all the investor collectors to get out and just leave the one who collect because they love it!

Im all about welcoming new people to the hobby but would rather have discussions about whats fun to play rather than showing off what you have thats rare and worth money!

[lekrang]

Thats why Im hoping the collecting bubble bursts!

Id like all the investor collectors to get out and just leave the one who collect because they love it!

Im all about welcoming new people to the hobby but would rather have discussions about whats fun to play rather than showing off what you have thats rare and worth money!

 

It is eventually going to happen.

New generations aren't attached to physical media.

People who love it will keep their collections unless they encounter difficult financial times.

Most of the people who got into the current collecting mania trend just because it is trendy and they like playing a game or two like once every six months will eventually sell.

I already see allot of people who acquired large quantities of retro games in the past few years and went way over budget selling it all off on facebook groups.

 

It's not about IF it will happen but WHEN.

[kwnage]

Do you have a Chromecast, and if so, does the same symptom happen when you are using it while powered by the TV's USB?

I have an Amazon FireTV but that thing doesn't have a power LED, so I can't see if it turns on and off randomly while the TV is off. I could try something simple like a USB light or fan if i were really eager to know...

 

Just to clarify: The SuperNt doesn't turn off while the TV is on, it'll run fine for hours, so that's not an issue. But it's when the TV is off that it'll turn on sometimes, so I suspect some kind of power cycling on the TV's USB.

Edited February 19, 2018 by kwnage

[CZroe]

In all cases such options should come with a disclaimer and a hot-key on boot-up to restore "normal" hdmi behavior. I find the Super NT such a great system almost living up to all the claims made by analogue, but without a tearing and frame drop free hdmi mode at original speed it is not really 100%. But i am pretty optimistic that a way will be found and implemented via firmware update, if not now maybe after the dust has settled a bit.

Square peg. Round hole. Shaving the leg usually breaks it.

 

If you want 60.09hz output, OSSC-style, then it simply will not work with a lot of TVs, just like the OSSC + SNES. Because there is a 60.09hz mode and the delay averages half a frame (resets to no delay after every frame drop), most consider the request for 60.09hz fulfilled.

[5200Fanatic]

Thats why Im hoping the collecting bubble bursts!

Id like all the investor collectors to get out and just leave the one who collect because they love it!

Im all about welcoming new people to the hobby but would rather have discussions about whats fun to play rather than showing off what you have thats rare and worth money!

 

 

It will happen because these massive collections can only be sold (mostly) in large chunks. It is much tougher to sell than to acquire.

Edited February 19, 2018 by 5200Fanatic

[Mattelot]

Thats why Im hoping the collecting bubble bursts!

Id like all the investor collectors to get out and just leave the one who collect because they love it!

Im all about welcoming new people to the hobby but would rather have discussions about whats fun to play rather than showing off what you have thats rare and worth money!

 

I agree. I do it because when I was a kid, my parents didn't have a lot of money so my gaming experience was limited to what I could rent at the video store. Now, I can play/own all the games I read about in Nintendo Power while filling in that void in my nostalgia bucket list.

 

Some of them, I had to scratch off the ownership side due to individual values however, the NT mini jailbreak allowed me to at least play them.

[Great Hierophant]

Apart from that I found the following incompabilities:

 

- JP Samurai Spirits crashes after the initial Logo, sometimes the cherry-blossom animation runs for half a second before the screen blanks.

- JP Accele Brid crashes during gameplay - music continues playing but game freezes.

- JP lets you only use hotkeys during fades to black. As these become very seldom in game, hot-keys cease to work for long periods of time

- JP Zootoo Mahjong (my favourite Mahjong) no hot-keys at all

- Pac-Man (A&S NES Hack) graphics corruption

I didn't check Samurai Spirits, but Samurai Shodown has a known issue with it not loading on JB firmware, I believe in a similar manner. Samurai Shodown has no issues in sd2snes.

I had no issues with Accele Brid & Bakukyuu Renpatsu!! Super B-Damon in sd2snes. No crashes, no difficulty getting to the settings menu. I did get Accele Brid to crash with JB pretty quickly after starting the first level.

Pac-Man (A&S NES Hack) shows similar graphics corruption on real hardware and Higan. The hacker intro works OK.

Edited February 19, 2018 by Great Hierophant

[Videodr0me]

Square peg. Round hole. Shaving the leg usually breaks it.

 

If you want 60.09hz output, OSSC-style, then it simply will not work with a lot of TVs, just like the OSSC + SNES. Because there is a 60.09hz mode and the delay averages half a frame (resets to no delay after every frame drop), most consider the request for 60.09hz fulfilled.

 

I strongly disagree for a number of reasons:

a) first even if he can only provide a solution on the level of the OSSC - and there should be no obvious reason why he can't - it would be a great plus. It should be optional, of course and not the default. I can't imagine anybody objecting such an option, even if it only works on "some" tvs. Nobody is forced to use it

b) I strongly believe (having done some work on designing scalers myself) that kevtris can do a much better job than the OSSC as he has direct access to the snes output and much more command of the interlocking timing, He might need some amount of buffered lines in SNES resolution, but as his fully buffered mode shows he should have ample of ram to do that.

c) I reckon that it might not be his first priority after launch, but as a converter to analog is planned, he is probably going to revisit his HDMI output formats anyhow. His engineering pride should propel him towards offering something which is at least on par with OSSC - maybe not now but in the not so far away future.

 

And do not get me wrong: I mostly love the Super NT - and expect the firmwares to get better over time.

[Videodr0me]

I didn't check Samurai Spirits, but Samurai Shodown has a known issue with it not loading on JB firmware,I believe in a similar manner. Samurai Shodown has no issues in sd2snes.

I had no issues with Accele Brid & Bakukyuu Renpatsu!! Super B-Damon in sd2snes. No crashes, no difficulty getting to the settings menu. I did get Accele Brid to crash with JB pretty quickly after starting the first level.

Pac-Man (A&S NES Hack) shows similar graphics corruption on real hardware and Higan. The hacker intro works OK.

 

Samurai Showdown I did not try. Samurai Spirits crashes on all JP versions I could find even on an sd2nes, but will try to locate a real cart. Accele Brid does crash often but not always, could you retry a couple of times on your sd2nes (we only tried it once on the sd2nes and it crashed but much later). Pac-Man is ok then, good that you checked.

[RabidWookie]

 

If the only reason they are asking is so they can sell their collection now before the bottom falls out of the market when the chip support happens, if it happens.

The cart market will not drop from FPGA chip replication. High quality NES flash carts have been around for several years, NES cart prices have skyrocketed in that time frame.

[NE146]

Samurai Showdown I did not try. Samurai Spirits crashes on all JP versions I could find even on an sd2nes, but will try to locate a real cart. Accele Brid does crash often but not always, could you retry a couple of times on your sd2nes (we only tried it once on the sd2nes and it crashed but much later). Pac-Man is ok then, good that you checked.

I played Samurai Spirits (j) just the other day using an SD2SNES and had no problems.. but my Super NT is still stock firmware

Edited February 19, 2018 by NE146

[RabidWookie]

I think the NES collector market is now peaked, and the 16 bit systems likely will in a couple of years (or sooner). Modern video games have hit a point of diminishing returns in terms of their graphics and complexity, which I think is part of why so many people are looking back at the simpler classics. Soon holographic and augmented reality gaming will be mainstreamed and perfected, and that will draw a lot of the casual retro gaming fans away.

[Beer Monkey]

 

I strongly disagree for a number of reasons:

a) first even if he can only provide a solution on the level of the OSSC - and there should be no obvious reason why he can't - it would be a great plus. It should be optional, of course and not the default. I can't imagine anybody objecting such an option, even if it only works on "some" tvs. Nobody is forced to use it

b) I strongly believe (having done some work on designing scalers myself) that kevtris can do a much better job than the OSSC as he has direct access to the snes output and much more command of the interlocking timing, He might need some amount of buffered lines in SNES resolution, but as his fully buffered mode shows he should have ample of ram to do that.

c) I reckon that it might not be his first priority after launch, but as a converter to analog is planned, he is probably going to revisit his HDMI output formats anyhow. His engineering pride should propel him towards offering something which is at least on par with OSSC - maybe not now but in the not so far away future.

 

And do not get me wrong: I mostly love the Super NT - and expect the firmwares to get better over time.

 

Kevin has already said he's working on a major video update. Scanlines and gamma are being redone. Output is already almost on par with the OSSC.

 

It won't be at 60.09hz, but that's a whole other thing.

[Toth]

I have an SD2SNES but I still like to pick up the real cartridges for the games I have a stronger memory or connection with. When I got my Super Nt I decided to take a look at some of those games since it had been awhile and Lufia and Lufia II along with an English copy of terranigma are ridiculously expensive. I thought I had the really expensive games covered with Chrono Trigger and Earthbound but nope not even close.

Edited February 19, 2018 by Toth

[Niko]

So, I have a weird problem with the Super NT and an SD2SNES.

 

The SD2SNES works fine in my original SNES. But when I put it in the Super NT, on first boot I get just a black screen. When I turn the Super NT off and on again (not reset) then it's fine. It'll keep working through reboots and on/offs until I leave it turned off for a while. After which, I have to turn it on twice again to get it working.

 

Nothing seems wrong with its performance in the Super NT other than this one weird quirk.

 

 

I can confirm the same thing happens to me, it even did it with my original super metroid cart, and then again when I switched back to the SD2SNES.

[F34R]

I will use my SD2SNES for games, but I do like "collecting" games that hold a piece of my heart from the SNES days. I have most of the games that aren't compatible with the SD2SNES that I wanted. There are some I still need to get though.

 

• Doom
• Winter Gold
• Kirby’s Dream Land 3
• Power Rangers Zeo: Battle Racers
• Star Ocean
• Street Fighter Alpha 2

I'll get more and more game carts as I find really good deals on them just to increase my collection, but I'm not really into collecting enough to pay high prices.

[zeroG]

I will use my SD2SNES for games, but I do like "collecting" games that hold a piece of my heart from the SNES days. I have most of the games that aren't compatible with the SD2SNES that I wanted. There are some I still need to get though.

 

• Doom
• Star Ocean

 

Star Ocean (hacked version) works on the SD2SNES. Doom has really poor framerate, I doubt you want to play that.

[F34R]

 

Star Ocean (hacked version) works on the SD2SNES. Doom has really poor framerate, I doubt you want to play that.

I was wanting the originals. I've played Doom plenty, and it doesn't bother me. It's more of a nostalgia collection for Doom though.

[lekrang]

I was wanting the originals. I've played Doom plenty, and it doesn't bother me. It's more of a nostalgia collection for Doom though.

 

I hope you know japanese.

I personally own Star Ocean for the SFC and used to use it with the translation patch on the retron 5.

I have since built myself a repro with the translation for use on my snes.

 

Looking forward to seeing if it works on my super nt once it arrives.

[Andromeda Stardust]

I have an Amazon FireTV but that thing doesn't have a power LED, so I can't see if it turns on and off randomly while the TV is off. I could try something simple like a USB light or fan if i were really eager to know...

 

Just to clarify: The SuperNt doesn't turn off while the TV is on, it'll run fine for hours, so that's not an issue. But it's when the TV is off that it'll turn on sometimes, so I suspect some kind of power cycling on the TV's USB.

 

just use a wall charger to be safe.

[kwnage]

Nah, my power strip is cluttered enough everything works fine when the SuperNt is powered by my Xbox One, which can supply at least 900mA as per USB3.0 spec. Safe enough for me.

Edited February 19, 2018 by kwnage

[Andromeda Stardust]

Nah, my power strip is cluttered enough everything works fine when the SuperNt is powered by my Xbox One. Safe enough for me.

 

i have a 4-port radioshack charger thats perfect. i wish id bought more before they went bankrupt.

[Jagasian]

Last night on my Super NT and sd2snes, I was playing the latest GoodSNES Monopoly v1.1 ROM for about 5 minutes, with 4 players. When one of the players picked up a chance card, the game froze and would not respond to any input. The Super NT menu was accessible by pressing down and select.