Mega Sg (FPGA Genesis)

The place for all discussion on gaming hardware
User avatar
Galdelico
Posts: 257
Joined: Thu Nov 17, 2016 12:58 pm
Location: Italy

Re: Mega Sg (FPGA Genesis)

Post by Galdelico »

Fudoh wrote:
Apologies for sounding like a complete dummy, but what are those 512/768/720 numbers?
it's the resulting width of the image depending on your OSSC settings.

512 = 2x 256 (optimized sampling width)
768 = 3x 256 (optimized sampling width)
720 = 2x 360 (generic 4:3 sampling width)

512 and 768 are achieveable with the optimized setitng, while 720 is what you get in generic mode.
Got it. Thanks!
MidOrFeed2015
Posts: 168
Joined: Wed Jul 01, 2015 9:11 am

Re: Mega Sg (FPGA Genesis)

Post by MidOrFeed2015 »

I am guessing that when the game gear adapter comes out, it won't be possible to use that on a real genesis.
User avatar
Lawfer
Posts: 2283
Joined: Fri Dec 01, 2006 3:30 am

Re: Mega Sg (FPGA Genesis)

Post by Lawfer »

MidOrFeed2015 wrote:I am guessing that when the game gear adapter comes out, it won't be possible to use that on a real genesis.
No genesis can't play Game Gear games.
User avatar
maxtherabbit
Posts: 1763
Joined: Mon Mar 05, 2018 4:03 pm

Re: Mega Sg (FPGA Genesis)

Post by maxtherabbit »

Lawfer wrote:
MidOrFeed2015 wrote:I am guessing that when the game gear adapter comes out, it won't be possible to use that on a real genesis.
No genesis can't play Game Gear games.
Correct. There was actually an entire discussion on either the most recent or second most recent retro roundtable detailing why it can't.
User avatar
donluca
Posts: 852
Joined: Sat Feb 28, 2015 8:51 pm
Location: Italy
Contact:

Re: Mega Sg (FPGA Genesis)

Post by donluca »

It can't play GG games directly, but through a very convoluted route of having the GG rom converted to master system and using the converter to play that master system game on the Mega Drive, yeah, you can "play" a GG gear on a Mega Drive.
User avatar
BuffaloWing
Posts: 50
Joined: Tue Feb 02, 2016 1:31 am
Contact:

Re: Mega Sg (FPGA Genesis)

Post by BuffaloWing »

Anyone noticed the small cartridge picture on the lower right of the menu incorrectly shows the back side for both US and EUR format? The JPN version correctly shows the front (label side) of the cart. If you go into the option screen for changing the "SKIN", choose another region and save afterward, an animation of the cartridge spinning clearly shows there is a front side. Seems like a glitch/bug that wasn't caught in the testing.
User avatar
Konsolkongen
Posts: 2309
Joined: Fri May 16, 2008 8:28 pm
Location: Denmark

Re: Mega Sg (FPGA Genesis)

Post by Konsolkongen »

They also had JP style carts showing in the EU skin at first >_<

But with amount of pirated games they display on their site it's probably hard for them to keep track :D Sonic 3 Complete, the classic Alien Solder in US and they also have a Jap style cart of Gleylancer with PAL label ;)

https://www.analogue.co/assets/content/ ... imated.gif

EDIT: Completely missed the weird JAP/EU hybrid of Battle Mania 2.
GameLifter
Posts: 11
Joined: Thu Mar 28, 2019 1:26 am

Re: Mega Sg (FPGA Genesis)

Post by GameLifter »

Looks like firmware version 4.4 fixed the issues I was having with Final Fight CD and Silpheed. Good thing since I was ready to get my Model 2 Sega CD recapped and have the laser replaced when it turns out it's not needed. Silpheed still has disc read errors though but this behavior is expected. I am interested in a Model 1 Sega CD though.....
User avatar
FBX
Posts: 2347
Joined: Wed Feb 18, 2015 10:18 am
Location: DFW area, Texas
Contact:

Re: Mega Sg (FPGA Genesis)

Post by FBX »

Did a Youtube video on Perfectly centered and calibrated video settings for each core:

https://youtu.be/dzVu05ACVhc

At a later point in the video during the Colecovision settings, I realized I forgot to disable vertical interpolation for SMS and Colecovision, but I caught it and went back and corrected both. Just a heads-up on that if you spot the error and freak out ;-)
User avatar
Fudoh
Posts: 13015
Joined: Mon Mar 06, 2006 3:29 am
Location: Germany
Contact:

Re: Mega Sg (FPGA Genesis)

Post by Fudoh »

thanks for the video! Nicely done.

at 48:50 in the video you left the horizontal interpolation for GG enabled despite using the square pixels scaling option. Is that correct? Doesn't the square pixel option automatically provide an integer scale on the horizontal axis? EDIT: I think you go into it again with the 720p settings at 1:01:24 and at the very end, but why doesn't "square pixel" provide an integer scale? Shouldn't it as it does on the 320px MD settings?
H6rdc0re
Posts: 224
Joined: Tue Jan 17, 2017 8:22 pm

Re: Mega Sg (FPGA Genesis)

Post by H6rdc0re »

Hopefully Kevtris will fix the scaling issues. I’ve done a feature request for both the Super NT and Mega SG for native 1600x1200p and/or 1920x1200p output. Also a scanline fix for 4x/5x scaling output with the option for true black scanlines. Hopefully these will get to Kevtris.
User avatar
FBX
Posts: 2347
Joined: Wed Feb 18, 2015 10:18 am
Location: DFW area, Texas
Contact:

Re: Mega Sg (FPGA Genesis)

Post by FBX »

Fudoh wrote:thanks for the video! Nicely done.

at 48:50 in the video you left the horizontal interpolation for GG enabled despite using the square pixels scaling option. Is that correct? Doesn't the square pixel option automatically provide an integer scale on the horizontal axis? EDIT: I think you go into it again with the 720p settings at 1:01:24 and at the very end, but why doesn't "square pixel" provide an integer scale? Shouldn't it as it does on the 320px MD settings?
Kevtris labels it "square pixels" based on the LCD of the original handheld Game Gear. However, it's in reality a non-digital square pixel aspect correction, and thus requires horizontal interpolation. I believe in the video you can see me demonstrate this by scrolling through the different integer scales, and the "square pixel" label doesn't land on one. It's just a bad label Kevtris gave it in my opinion. He should have just called it "Handheld AR" or something like that.
copy
Posts: 232
Joined: Fri Apr 29, 2016 10:38 pm

Re: Mega Sg (FPGA Genesis)

Post by copy »

FBX, your Genesis horizontal position setting works for centering 320-width games, but leaves 256-width games off center. I settled on 21 as a compromise (for 4x).

Also, are you confident about the Game Gear's aspect ratio? You and Kevtris seem to be targeting a 1.3:1 AR, but I've always understood it to be 1.33:1. Sega's technical manual seems to back this up (65.27 mm wide x 48.90 mm high = 1.33:1). I think you mentioned in the video that you measured a GG with a caliper to arrive at this AR. I will try to check my GG with a ruler tonight, out of curiosity.

(Speaking of Kevtris's bad labels, the Game Gear ones for "4:3 for 16:9" are very strange, resulting in a 1.44:1 ratio.)
User avatar
FBX
Posts: 2347
Joined: Wed Feb 18, 2015 10:18 am
Location: DFW area, Texas
Contact:

Re: Mega Sg (FPGA Genesis)

Post by FBX »

copy wrote:FBX, your Genesis horizontal position setting works for centering 320-width games, but leaves 256-width games off center. I settled on 21 as a compromise (for 4x).
Since we can't have independent centerings for each mode of the Genesis, I decided to base the center values for 320 since 75% of the Genesis library uses this mode for main gameplay.

Also, are you confident about the Game Gear's aspect ratio? You and Kevtris seem to be targeting a 1.3:1 AR, but I've always understood it to be 1.33:1. Sega's technical manual seems to back this up (65.27 mm wide x 48.90 mm high = 1.33:1). I think you mentioned in the video that you measured a GG with a caliper to arrive at this AR. I will try to check my GG with a ruler tonight, out of curiosity.
I believe I mentioned Kevtris's values weren't perfect (off by a couple pixels) but it was so close that I felt it wasn't anything to get into a twist over. Also that technical manual may be basing the dimension values off the entire screen rather than the active lit pixel area. This is something you can test for posterity if you like, and then we can determine if it's worth hassling over. As I said, my findings showed Kevtris was very close, and enough for me to recommend it without making a fuss.
copy
Posts: 232
Joined: Fri Apr 29, 2016 10:38 pm

Re: Mega Sg (FPGA Genesis)

Post by copy »

FBX wrote:I believe I mentioned Kevtris's values weren't perfect (off by a couple pixels) but it was so close that I felt it wasn't anything to get into a twist over. Also that technical manual may be basing the dimension values off the entire screen rather than the active lit pixel area. This is something you can test for posterity if you like, and then we can determine if it's worth hassling over. As I said, my findings showed Kevtris was very close, and enough for me to recommend it without making a fuss.
I've confirmed the active pixels on my my Game Gear measure at 65 x 49 mm, so 1.33:1 it is.

I'm not saying this is the end of the world, just trying to helpfully point out an area for improvement in the settings. The difference between 1.30:1 and 1.33:1 is pretty noticeable when you're enlarging the image on an HDTV (you're talking a 34 pixel difference at 7x). I've always appreciated your commitment to accuracy and fidelity, so I'd hope you'd want to nail this one too.
User avatar
FBX
Posts: 2347
Joined: Wed Feb 18, 2015 10:18 am
Location: DFW area, Texas
Contact:

Re: Mega Sg (FPGA Genesis)

Post by FBX »

copy wrote: I've confirmed the active pixels on my my Game Gear measure at 65 x 49 mm, so 1.33:1 it is.
When I put 65x49 in my paint program, it claims that AR is 1.3265:1. Nevertheless, I'll look into it and post an update for that core.

Edit: Technical manual would likely be even more accurate then, so the actual AR is 1.3348:1.

New values for 1080 mode:

1345x1008 enable H, disable V

New values for 720 mode:

961x720 enable H, disable V
copy
Posts: 232
Joined: Fri Apr 29, 2016 10:38 pm

Re: Mega Sg (FPGA Genesis)

Post by copy »

No offense FBX, but if I can be frank, I think you've gone way too far in the other direction now.
FBX wrote:When I put 65x49 in my paint program, it claims that AR is 1.3265:1. Nevertheless, I'll look into it and post an update for that core.

Edit: Technical manual would likely be even more accurate then, so the actual AR is 1.3348:1.
We're talking third-decimal rounding errors here. It's obvious what Sega's goal was: this was, for all intents and purposes, a 4:3 display, matching the standard aspect ratio of the time. You could even watch your 4:3 TV broadcasts on it via the TV tuner.

(Note that the technical manual also incorrectly lists the pixel count as 160 x 146 instead of 144, so they could very easily be slightly off on their screen dimensions as well. Using this as a basis to calculate the AR out to 4 decimals rather than rounding to the standard 2 seems like an odd choice.)
FBX wrote:New values for 1080 mode:

1345x1008 enable H, disable V

New values for 720 mode:

961x720 enable H, disable V
This is incredibly silly. Reduce both those widths by one single pixel, and you get perfect 4:3.

Even better, for 720p/5x, a width of 960 gives you perfect 6x horizontal integer scaling, and you can disable H interpolation for gloriously sharp pixels. Are you seriously going to advise people to go with 961 and have to significantly soften the picture for the sake of a ~0.0014 difference from 4:3?
User avatar
FBX
Posts: 2347
Joined: Wed Feb 18, 2015 10:18 am
Location: DFW area, Texas
Contact:

Re: Mega Sg (FPGA Genesis)

Post by FBX »

You're right, I forgot to take into account rounding. I'll update both then.

1080p: 1344 x 1008, enable H, disable V

720p: 960x720 disable both H and V interpolation (new H position value of 3)

Totally missed those rounding errors.
User avatar
evil_ash_xero
Posts: 6181
Joined: Thu Jul 12, 2007 6:33 am
Location: Where the fish lives

Re: Mega Sg (FPGA Genesis)

Post by evil_ash_xero »

OK, what values do I need to have to have a proper 4:3 ratio in 480? I'm on a 16:9 monitor.

I'm leaving both interpolations on.
User avatar
evil_ash_xero
Posts: 6181
Joined: Thu Jul 12, 2007 6:33 am
Location: Where the fish lives

Re: Mega Sg (FPGA Genesis)

Post by evil_ash_xero »

Fudoh wrote:Horizontal scaling on 480p output is broken. I am not able to dial in a 2x integer horizontal scale. The horizontal sizing control adds 20 px per 320 to the counter (so you get 1x integer at 340), but since the max setting sis 640 and I would need 680 px on that counter, I can't get any proper looking horizontal scale on 480p output.

Is this still the case? I've noticed it goes to 640. So, this is an incorrect image?
User avatar
Fudoh
Posts: 13015
Joined: Mon Mar 06, 2006 3:29 am
Location: Germany
Contact:

Re: Mega Sg (FPGA Genesis)

Post by Fudoh »

disable advanced mode and go for the regular the regular 4:3 setting. This gives you an integer 2x scale for 320px wide games. You can disable the interpolation on both axis (if you like).
User avatar
Domino
Posts: 1346
Joined: Sat Feb 16, 2008 11:35 pm
Location: Florida

Re: Mega Sg (FPGA Genesis)

Post by Domino »

I'm getting my unit this week and Jailbreaking it. How's the default video/sound settings? Curious, since I'll run it in 1080p in maybe 5x max for MD stuff.
User avatar
FBX
Posts: 2347
Joined: Wed Feb 18, 2015 10:18 am
Location: DFW area, Texas
Contact:

Re: Mega Sg (FPGA Genesis)

Post by FBX »

Domino wrote:I'm getting my unit this week and Jailbreaking it. How's the default video/sound settings? Curious, since I'll run it in 1080p in maybe 5x max for MD stuff.
Defaults are not recommended. See my cheat-sheets for preferred settings:

http://www.firebrandx.com/downloads/Meg ... ition).txt

http://www.firebrandx.com/downloads/Meg ... ition).txt
User avatar
Domino
Posts: 1346
Joined: Sat Feb 16, 2008 11:35 pm
Location: Florida

Re: Mega Sg (FPGA Genesis)

Post by Domino »

FBX wrote:
Domino wrote:I'm getting my unit this week and Jailbreaking it. How's the default video/sound settings? Curious, since I'll run it in 1080p in maybe 5x max for MD stuff.
Defaults are not recommended. See my cheat-sheets for preferred settings:

http://www.firebrandx.com/downloads/Meg ... ition).txt

http://www.firebrandx.com/downloads/Meg ... ition).txt
Thanks, can you explain the part below that's bolded?
copy wrote:FBX, your Genesis horizontal position setting works for centering 320-width games, but leaves 256-width games off center. I settled on 21 as a compromise (for 4x).

Also, are you confident about the Game Gear's aspect ratio? You and Kevtris seem to be targeting a 1.3:1 AR, but I've always understood it to be 1.33:1. Sega's technical manual seems to back this up (65.27 mm wide x 48.90 mm high = 1.33:1). I think you mentioned in the video that you measured a GG with a caliper to arrive at this AR. I will try to check my GG with a ruler tonight, out of curiosity.

(Speaking of Kevtris's bad labels, the Game Gear ones for "4:3 for 16:9" are very strange, resulting in a 1.44:1 ratio.)
Does anyone have a few recommendation of the 256-width games?
Wolf_
Posts: 387
Joined: Sat Jun 25, 2016 10:10 pm

Re: Mega Sg (FPGA Genesis)

Post by Wolf_ »

I wonder if there is any chance of someone making a triad power supply for the mega sg, sega cd, and 32x...
spmbx
Posts: 482
Joined: Sat Aug 01, 2009 5:22 pm
Location: The Netherlands

Re: Mega Sg (FPGA Genesis)

Post by spmbx »

That’s a rather strange combination since you can’t use the 32x with the mega sg
Wolf_
Posts: 387
Joined: Sat Jun 25, 2016 10:10 pm

Re: Mega Sg (FPGA Genesis)

Post by Wolf_ »

spmbx wrote:That’s a rather strange combination since you can’t use the 32x with the mega sg
Can't use it... yet. They said that it could possibly be compatible in the future using the analogue converter. Which puts me back in the same sitatuation of not wanting to have 3 power cables going to three outlets, 2 of which attached to massive bricks.
User avatar
FBX
Posts: 2347
Joined: Wed Feb 18, 2015 10:18 am
Location: DFW area, Texas
Contact:

Re: Mega Sg (FPGA Genesis)

Post by FBX »

Domino wrote:
Does anyone have a few recommendation of the 256-width games?
You shouldn't worry about it. The difference is only a few pixels, and only 25% of the library uses 256 mode anyway for main gameplay.
User avatar
evil_ash_xero
Posts: 6181
Joined: Thu Jul 12, 2007 6:33 am
Location: Where the fish lives

Re: Mega Sg (FPGA Genesis)

Post by evil_ash_xero »

Any good programs to change the region of a game? I have mixed region games, and I get a little irritated changing the region of the system.
I've read you can change it in HEX editors, but that seems a bit confusing.
GameLifter
Posts: 11
Joined: Thu Mar 28, 2019 1:26 am

Re: Mega Sg (FPGA Genesis)

Post by GameLifter »

Wolf_ wrote:
spmbx wrote:That’s a rather strange combination since you can’t use the 32x with the mega sg
Can't use it... yet. They said that it could possibly be compatible in the future using the analogue converter. Which puts me back in the same sitatuation of not wanting to have 3 power cables going to three outlets, 2 of which attached to massive bricks.
I've been wondering about which ways the Mega Sg could support 32X games. Would they be able to do it by adding a 32X core to the FPGA on the Mega Sg then create a simple adapter for the cartridges? Or would they need to create an adapter with a whole extra FPGA in it that has the 32X core on it there to simulate it? On original hardware the 32X has to receive an analog signal from the Genesis/Mega Drive then the 32X is what outputs the signal to the screen. So, with the Mega Sg its digital signal would have to be converted to analog when going to the 32X but how would it output to a modern screen? Maybe the output can still be done digitally from the Mega Sg somehow or would the analog signal going out of the 32X have to be converted back to digital? Or is it more simple than I think?
Post Reply