Genesis / Megadrive core ported to MiST

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slingshot
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Re: Genesis / Megadrive core ported to MiST

Post by slingshot »

Wow! I assumed they finished with the Mega Drive. But I guess no new trick is used here.

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Re: Genesis / Megadrive core ported to MiST

Post by slingshot »

CPU overclock option:

https://github.com/mist-devel/mist-bina ... 190430.rbf

Good for 3D games, like Race Drivin'

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Re: Genesis / Megadrive core ported to MiST

Post by DanyPPC »

Good ! Thanks ;)

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Re: Genesis / Megadrive core ported to MiST

Post by DrOG »

WOW!!! :cheers:

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Re: Genesis / Megadrive core ported to MiST

Post by DanyPPC »

Which games are fixed with latest release Slingshot ?

https://github.com/mist-devel/mist-bina ... 190510.rbf

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Re: Genesis / Megadrive core ported to MiST

Post by slingshot »

One scene at Rocket Knight Adventures:
https://github.com/MiSTer-devel/Genesis ... /issues/46
The left side of Kawasaki Superbike Challenge
And there's a possibility of others which are using 2 column VSCROLL mode together with horizontal scroll.

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Re: Genesis / Megadrive core ported to MiST

Post by DanyPPC »

Many thanks for this fix :cheers:

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Re: Genesis / Megadrive core ported to MiST

Post by ghogan42 »

Hi All. On the MiSTer port of this core we've had a sound issue in Sonic and Knuckles and I was wondering if the same issue happens on the MiST port.

To get it, you'd have to run Sonic and Knuckles (I guess USA region?) not locked onto anything else. Then you'd have to beat the first two levels. After you beat the boss in Mushroom Hill 2, during the transition to the next stage there is some crackling.

You can also play the sound in the sound test from the level select screen

Code: Select all

Level Select (when not Locked-On to anything else)
In Mushroom Hill Zone, while hanging off one of the pulling machines, press left three times, right three times, and up three times. You should hear the ring sound. Pause and press A to be taken to the title screen. Highlight either Sonic or knuckles as your character, and press start while holding A. The menu shows all levels in the game, but some are specific to a certain character, so you can't play those if you picked an incompatible character. Any time you want to exit and select a different level, just repeat the code from right after the pulling machine part.
How to play the sample in the level select:

Code: Select all

Sound Test, press C to play sample.
Sound Test 01, stops audio.
Sound Test BD, distorting sample (press C multiple times. It doesn't distort unless you play it a few times).
20190604_065918-Sonic & Knuckles (World).png
We think it might just be a YM2612 emulation problem because the sound is also different than a real Genesis. But I figured we could see if it was a shared problem between MiST and MiSTer to rule out MiSTer's digital audio issues.

Here's what it sounds like on mister: https://drive.google.com/open?id=1aGqnG ... sWl_6LUV4I

Here's a sample from the level select playing sample BD on an actual Model 2 Genesis: https://drive.google.com/open?id=1dmPLT ... rkAQZmCs7-

Here's what the waveform looks like when it distorts.
Sonic_Knuckles_Distortion.PNG
Anyone want to test this? :D

EDIT: I was asked to post how this sounds when you play it one time from the sound test (mister vs real hardware)

Mister: https://drive.google.com/open?id=1hzN3r ... JNL2NYJrVx

Model 2 Genesis: https://drive.google.com/open?id=1pTvZM ... FVpXAXXUGR
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Re: Genesis / Megadrive core ported to MiST

Post by JamesF »

EDIT: I was asked to post how this sounds when you play it one time from the sound test (mister vs real hardware)
@jotego

The two samples sound very different regardless the LPF,, sounds like the MiSTer (maybe MiST?) YM3438 has a problem with the envelope emulation,, and maybe that what creates the distortion.

Can someone please confirm this audio distoriton on the MiST?
A recording of this BD sample on the MiST would by best, single time, and multiple times (keep pressing C).
The YM3438 on the MiSTer is a direct port from the MiST.
Last edited by JamesF on Tue Jun 04, 2019 8:06 am, edited 2 times in total.

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Re: Genesis / Megadrive core ported to MiST

Post by vebxenon »

SVP support has been released on MiSTer. Will this support be included on MiST? :D
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Re: Genesis / Megadrive core ported to MiST

Post by slingshot »

With another 128K RAM? I don't feel the force to convert it to SDRAM for only 1 game :)

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Re: Genesis / Megadrive core ported to MiST

Post by vebxenon »

slingshot wrote:With another 128K RAM? I don't feel the force to convert it to SDRAM for only 1 game :)
Virtua Racing is one of my favorite games ever :oops: :oops: . But don't worry :cheers:
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Re: Genesis / Megadrive core ported to MiST

Post by slingshot »

vebxenon wrote:
slingshot wrote:With another 128K RAM? I don't feel the force to convert it to SDRAM for only 1 game :)
Virtua Racing is one of my favorite games ever :oops: :oops: . But don't worry :cheers:
Ok, so you can take the job then :D

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Re: Genesis / Megadrive core ported to MiST

Post by vebxenon »

slingshot wrote:
vebxenon wrote:
slingshot wrote:With another 128K RAM? I don't feel the force to convert it to SDRAM for only 1 game :)
Virtua Racing is one of my favorite games ever :oops: :oops: . But don't worry :cheers:
Ok, so you can take the job then :D
I don't have coding skills :( :( :( . Sorry.
Just a computer and videogame lover :)

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Re: Genesis / Megadrive core ported to MiST

Post by vebxenon »

Just a computer and videogame lover :)

- Atari Jr 2600 clone
- Atari 7800 Peritel
- Atari XEGS
- Atari Lynx II
- Atari Jaguar
- MiST Board

slingshot
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Re: Genesis / Megadrive core ported to MiST

Post by slingshot »

Made on MiST:
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Re: Genesis / Megadrive core ported to MiST

Post by Gehstock »

:cheers:

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Re: Genesis / Megadrive core ported to MiST

Post by DanyPPC »

slingshot wrote:Made on MiST:
WoW :cheers:

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Re: Genesis / Megadrive core ported to MiST

Post by slingshot »

Ok, here it is:

https://github.com/mist-devel/mist-bina ... 190612.rbf

I've decided to have a separate core because of some reasons:
- Adding an SVP OSD for only one game is a bit annoying, and I still didn't write any code for cart auto-detection.
- With SVP, the core fills about 98% of the FPGA, and the compiling time increased a lot, and it really hinders further developments.

But there's a plus from the separate core: you can have a GEN_SVP.ROM with Virtua Racing, and it'll auto load when you load the core.

Note: it won't load "normal" carts correctly, the SVP chip messes up VDP DMA.

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Re: Genesis / Megadrive core ported to MiST

Post by hyperterminal »

Great, thank you! Virtua Racing is one of my favourite games and I never thought this would be possible on MiST.

A seperate core just for Virtua Racing has the additional advantage that you can set a custom joypad mapping just for this game in mist.ini. I always hated to shift gears with the dpad which is also used for steering.

This might be a dumb question, but where do I need to place the file "GEN_SVP.ROM"? I tried the root folder, the folder where the *.rbf resides and even a subfolder called "GEN_SVP", but nothing worked. With the subfolder "GEN_SVP" I can at least quickly select the desired rom.

There are still some small graphical glitches but I guess this is due to srg320 still working on the core.

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Re: Genesis / Megadrive core ported to MiST

Post by slingshot »

hyperterminal wrote: This might be a dumb question, but where do I need to place the file "GEN_SVP.ROM"? I tried the root folder, the folder where the *.rbf resides and even a subfolder called "GEN_SVP", but nothing worked. With the subfolder "GEN_SVP" I can at least quickly select the desired rom.
In the root folder, it works for me there.
There are still some small graphical glitches but I guess this is due to srg320 still working on the core.
I only see just some "wobbling" pixels, I think it just because using the SDRAM instead of internal BRAM, it won't be fixed (probably can be optimized a bit more, but I won't spend more time with it, for only one game - the source is there, if anyone interested, improve it). Actually I wonder it works so well. One year ago, even sprites were missed because the inadequate SDRAM bandwidth. Now it's (almost fully) enough for the SVP, too.

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Re: Genesis / Megadrive core ported to MiST

Post by krupkaj »

wow, this is great news. have to test it now :)

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Re: Genesis / Megadrive core ported to MiST

Post by DanyPPC »

PAL version is faster and has a few graphic glitches.
:cheers:

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Re: Genesis / Megadrive core ported to MiST

Post by vebxenon »

Thanks very very mucho, Slingshot :D :cheers: :cheers:
Just a computer and videogame lover :)

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Re: Genesis / Megadrive core ported to MiST

Post by seastalker »

Thank you Slingshot! The overclock feature makes it fun to toggle between my MiST/MiSTer and Mega SG. :) I look forward to trying out the Virtua Racing core.

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