Mega SD

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strygo
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Mega SD

Post by strygo »

I'm sure many of you watched Terra Onion's presentation today. I'm cautiously optimistic about the Mega SD. Apologies if I missed this, but has anyone in the community had access to a test unit? I'd love to pick one up, but being one of the first people who preordered an SSDS3, I'd like to avoid a repeat of that situation.
Hao
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Re: Mega SD

Post by Hao »

Mega SD looks sick AF but need confirmation any SD access noise is not present.

If FirebrandX helped with the audio circuit, hopefully this was already thought of.
Wolf_
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Re: Mega SD

Post by Wolf_ »

I believe some people were given early review units. Retrorgb posted a "Review coming soon" video in response to the pre-order opening.

But I'm 100% waiting until it has been out for awhile and reviewed by electrical engineers before I buy it. I'm curious how they implemented a sega cd fpga and powered it entirely from the cartridge slot. Don't get me wrong I'm super excited if we don't need a sega cd power brick going to the console but given their past history of using components backwards and mixing ground planes I'm just going to wait and see if they have this thing working correctly before I buy it.
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FBX
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Re: Mega SD

Post by FBX »

They got the SD card access noise down to bare minimal levels and spent quite some time on it. I was able to show that it wasn't coming from the audio circuit, as with the audio circuit completely removed, the SD access noise was coming through to the console regardless. So they spent considerably time hiring additional EE's to work on it and did several revision changes, and got it down to where I don't even hear it on the Mega Sg myself. Original hardware you have to crank the volume up on your audio receiver to catch wind of it during muted boot sequences.

The only other minor difference is I was caught in a dilemma where the PCM is LPF'd on real hardware while CDDA was high-range boosted. You can't really do this at the same time in the analogue output stage, so I left them both unfiltered as far as going into the consoles (the consoles themselves may apply filtering anyway if unmodded). So any comparisons you see of audio between original hardware and the Mega SG, please remember that the Mega SG sounds just like the CDDA tracks when ripped directly from the disc. The difference compared to real hardware is minor though, so only the extreme anal-retentive types are going to have any gripes. The outside people brought in to independently test were actually quite happy with it.
naz
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Re: Mega SD

Post by naz »

Hello FBX, do you know if the improvements on access noise are something we can implement on the existing ssd3s??
spmbx
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Re: Mega SD

Post by spmbx »

I don’t really understand why it’s called a sega cd ODE if it emulates the entire console. That’s really something different.
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CMcK
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Re: Mega SD

Post by CMcK »

It’s arguably the only way an ODE could be implemented for the Mega Drive.
spmbx
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Re: Mega SD

Post by spmbx »

Well yes, you can’t do an ODE if you leave out the console entirely. Might as well call the mister an ODE. A sega cd ODE would be a gdemu-like device i plug into my segacd unit, not this.
fernan1234
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Re: Mega SD

Post by fernan1234 »

spmbx wrote:Well yes, you can’t do an ODE if you leave out the console entirely. Might as well call the mister an ODE. A sega cd ODE would be a gdemu-like device i plug into my segacd unit, not this.
A big part of me would have preferred this in order to not need to emulate (or "simulate") anything about the M/Sega CD, while simply avoiding the need to rely on its crappy mechanical drive and optical media. Plus, would be able to keep an awesome-looking Mega CD 1 unit attached to a Mega Drive, keeping the tower of power look in place!
SavagePencil
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Re: Mega SD

Post by SavagePencil »

spmbx wrote:I don’t really understand why it’s called a sega cd ODE if it emulates the entire console. That’s really something different.
It's not emulating the core Genesis, is it? AFAIK, it emulates the drive and the additional 68000 and the chips in the SegaCD. Hair-splitting?
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Re: Mega SD

Post by spmbx »

We’re saying the same thing. It emulates the entire sega cd console, it’s not an optical drive emulator. This isn’t even close to hair-splitting.
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BuckoA51
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Re: Mega SD

Post by BuckoA51 »

While I imagine the FPGA implementation of the MegaCD is super accurate I can't help feel the same way, I'd rather have as close to original hardware as possible and an ODE that sat in the SegaCD and literally just emulated the optical drive part.

Nevertheless there's no doubting this is extremely cool. If it fixes the questionable design issues on the Everdrive that DB Electronics found I'll probably pick one up just for that.
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FBX
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Re: Mega SD

Post by FBX »

naz wrote:Hello FBX, do you know if the improvements on access noise are something we can implement on the existing ssd3s??
Negative, it required several revision changes on how power regulation was handled and routed. Not possible on existing SSDS3's.
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Gara
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Re: Mega SD

Post by Gara »

BuckoA51 wrote:While I imagine the FPGA implementation of the MegaCD is super accurate I can't help feel the same way, I'd rather have as close to original hardware as possible and an ODE that sat in the SegaCD and literally just emulated the optical drive part.

Nevertheless there's no doubting this is extremely cool. If it fixes the questionable design issues on the Everdrive that DB Electronics found I'll probably pick one up just for that.
I'm with you there even it would have been terribly unpractical. Considering how few working units show up on ebay compared to broken. I would at least like to be able to leave my Sega cd plugged in. I'm not happy I'll have to unplug my Sega cd each time to use the Megasd. Adding another Genesis to my already bloated collection seems like the only good option. Might be a good excuse to do a TBP model 2. I have a Megasg but it's such a pain messing with all the audio options and being limited to my modern TV.

I thought about reselling my x7 everdrive but it looks like it will still have a place. I depend on it as a ram cart. Selling it would only make sense if I completely got rid of my Sega cd units. The model 1 Sega cd is just too damn cool to part with.
FBX wrote:
naz wrote:Hello FBX, do you know if the improvements on access noise are something we can implement on the existing ssd3s??
Negative, it required several revision changes on how power regulation was handled and routed. Not possible on existing SSDS3's.
With them delaying production of the next batch of ssds3 units until late summer it would be pretty amusing if they snuck another revision in. I'd consider it a good thing, but the community is so touchy about that stuff.
PixelDharma
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Re: Mega SD

Post by PixelDharma »

spmbx wrote:We’re saying the same thing. It emulates the entire sega cd console, it’s not an optical drive emulator. This isn’t even close to hair-splitting.
I guess the difference from something like the SSDS3 (which also replaces the entire CD unit) is that the Sega CD had additional hardware functions being replaced with an FPGA here, while the PC Engine/TurboGrafix CD is, as I understand it, just a bulky storage method. So you could call the SSDS3 an ODE but not the MegaSD.
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Syntax
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Re: Mega SD

Post by Syntax »

No 32x mode?
mario64
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Re: Mega SD

Post by mario64 »

Syntax wrote:No 32x mode?
Mega SD supports 32x cartridge-based games (requires a 32x) but I don’t think you can play the small handful of 32x disc-based games. Or perhaps with the adapter they mentioned it can play those disc games?
SamIAm
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Re: Mega SD

Post by SamIAm »

Any word on compatibility with combo systems like the CDX, X'EYE and Laseractive?

I'm also in the camp that would have preferred a simple replacement for the optical drive. I would have bought that immediately, but this? I'll wait until my real hardware breaks. I just re-greased the gears a couple of months ago.
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Re: Mega SD

Post by FBX »

SamIAm wrote:
I'm also in the camp that would have preferred a simple replacement for the optical drive. I would have bought that immediately, but this? I'll wait until my real hardware breaks. I just re-greased the gears a couple of months ago.
Damned if you do, damned if you don't. FAR more people were going to pass on the device if it had just been an ODE laser replacement. I saw several posts stating as much.
SamIAm
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Re: Mega SD

Post by SamIAm »

FBX wrote:Damned if you do, damned if you don't. FAR more people were going to pass on the device if it had just been an ODE laser replacement. I saw several posts stating as much.
Yeah, I don't blame them for making that call. This is a very cool device regardless, no doubt about it.

I'll just have to hold out hope that someone capable thinks there is still a market for an ODE.
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Gara
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Re: Mega SD

Post by Gara »

SamIAm wrote:Any word on compatibility with combo systems like the CDX, X'EYE and Laseractive?

I'm also in the camp that would have preferred a simple replacement for the optical drive. I would have bought that immediately, but this? I'll wait until my real hardware breaks. I just re-greased the gears a couple of months ago.
I can't speak for the laser active but it's a no on jvc and x'eye for cd support. You could still play mega drive roms but it disables cd game playback for the same reason you can't have a Sega cd plugged in. Something about the cd bus. Maybe if there was a way to disable the cdrom?
Wolf_
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Re: Mega SD

Post by Wolf_ »

Well technically it is an ode because it is still emulating the optical drive, it is just doing the rest of the console as well.

Besides most people think the tower of power looks terrible (or at least that was by far the most popular opinion for 25 years+) and that needing 3 power bricks is BS. I'm sure if a public vote were to have been held having the cartridge do the entire console would have won by miles. And if you want the sega cd around for aesthetic reasons you can leave it hooked up without any power going to it. The only concern I have for this is if the cartridge port delivers enough power to properly simulate the sega cd and read the data (and if the fpga coding was done well).
SamIAm
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Re: Mega SD

Post by SamIAm »

Gara wrote:
SamIAm wrote:Any word on compatibility with combo systems like the CDX, X'EYE and Laseractive?

I'm also in the camp that would have preferred a simple replacement for the optical drive. I would have bought that immediately, but this? I'll wait until my real hardware breaks. I just re-greased the gears a couple of months ago.
I can't speak for the laser active but it's a no on jvc and x'eye for cd support. You could still play mega drive roms but it disables cd game playback for the same reason you can't have a Sega cd plugged in. Something about the cd bus. Maybe if there was a way to disable the cdrom?
That's a drag. Those systems will be half-junk when their drives die. At least for now.

I'm looking at the Console5 wiki and comparing the various Sega CD versions, and the model 1, model 2 Sony version and X'Eye seem to share the same chips for operating the CD drive and could probably have a common ODE. The model 2 Funai version, Laseractive and CDX each use unique chipsets. So, it's not a completely fractured market, but it's not ideal, either.
Wolf_ wrote:The only concern I have for this is if the cartridge port delivers enough power to properly simulate the sega cd and read the data (and if the fpga coding was done well).
Apparently it uses less power than Virtua Racing.

As for accuracy, that's the million-dollar question at this point. I'm sure it's good, but is it 100%? We'll just have to wait and see.
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Gara
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Re: Mega SD

Post by Gara »

From what I've read some poor unfortunate soul went through the entire redump set to test compatability. I'm sure we are going to see a ton of bugs that only pop up during extended gameplay. I can only hope they are faster to patch than the ssds3. Lords of thunder still tries to burst my eardrums everytime it gets past the end credits. The theory is it has something to do with the seek time.
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Team Andromeda
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Re: Mega SD

Post by Team Andromeda »

Its sound almost too good to be true, but I've put an order in for one. The Mega CD drive and its games are no spring chickens anymore :)
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hugo19941994
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Re: Mega SD

Post by hugo19941994 »

SamIAm wrote:As for accuracy, that's the million-dollar question at this point. I'm sure it's good, but is it 100%? We'll just have to wait and see.
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BONKERS
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Re: Mega SD

Post by BONKERS »

FBX wrote:
SamIAm wrote:
I'm also in the camp that would have preferred a simple replacement for the optical drive. I would have bought that immediately, but this? I'll wait until my real hardware breaks. I just re-greased the gears a couple of months ago.
Damned if you do, damned if you don't. FAR more people were going to pass on the device if it had just been an ODE laser replacement. I saw several posts stating as much.
Yeah going the cart route like this seems like a much better option IMO. More accessible and there are only so many of the original units laying around.(As cool as it looked)
fernan1234
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Re: Mega SD

Post by fernan1234 »

Gara wrote:I'm sure we are going to see a ton of bugs that only pop up during extended gameplay. I can only hope they are faster to patch than the ssds3.
There are still compatibility issues with the SSDS3 like the one you mentioned, a lot of games also make unconventional requests, etc., and tons of games in the PCE CD as well as the Mega CD library are games that relatively few people play, so the bugs often go unreported.

When more than the optical drive is emulated by the FPGA there are even more potential points of failure. Still, I'm sure compatibility will be pretty good in general, especially for the more popular games which probably will be fixed more quickly if there are bugs.
Gara wrote:ords of thunder still tries to burst my eardrums everytime it gets past the end credits.
It doesn't help that the audio levels on the SSDS up to the current revision are very high. It sounds impressive when you listen to a clean audio track, but it also amplifies, for example, the feedback noise often present in voiced dialogue recordings or recorded sound effects (check the intro cutscenes of Advanced V. G. for a good example).
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evil_ash_xero
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Re: Mega SD

Post by evil_ash_xero »

Is this by the same folks who make the thing for the Turbo?
If so, I'll wait until the bugs are discovered and sorted out.
But looks pretty damn promising. I was wanting a Sega CD, for just a couple of games, so I couldn't really justify it. But this would solve that issue.
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Re: Mega SD

Post by rama »

Nice idea, to replace the entire Mega CD hardware with a single cartridge.
This is great value to people that don't yet have a Mega CD unit, or people that dislike how bulky the addon is.
I see prices way up there for even the MCD2, often broken ("untested"), so in my opinion the price tag represents the value well.

I didn't realize that SD card access would be an audio quality hazard. Nice to know it's already been taken care of though :)
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