Genesis / Megadrive core ported to MiST

[javidoom]

OMG!

I have to test this core the weekend!!!

Thanks!!!

[jotego]

I have some YM2612 chips to take measurement but I do not have a board built for it.

The author of that VHDL "sauraen" makes YM2612 boards.

https://www.youtube.com/watch?v=1nM5-QfIv_c

I have made contact with him. He read the original look-up tables for the sine wave and the exponential functions from the chip. That's critical for accuracy. That part of the information is public now.

[Brt]

Great news!
Thanks for all involved and keep up the good work!

[jotego]

I have got the first sine wave out of the OPN (FM synthesizer operator of YM2612). This is based on the work Sauraen made reverse engineering the OPN. This is the first milestone. You can check an image of it on my twitter account here

I found some minor errors on Sauraen interpretation of the die picture and send them back to him. So I'm glad I could help debugging the OPN.

For the rest of the YM2612 there are no reverse engineered data so I will just replicate the chip functionality using my own code. Nonetheless, the OPN is critical for sound fidelity so I'm glad we have this part of the circuit exact.

[fury23]

Great news, thank you!

[DrOG]

Just tried DuneII, altought it has some graphic glitches, it is well playable. With sound it would be even more fascinating!

Thanks for your fantastic work!!!

[mahen]

Hehe, by any chance, if someone could add 15 KHz support... I know it's not the priority, I'll be patient

[jotego]

Sound update 29-Jan-2017

I found out this week the correct way of calculating FM feedback combining the information Sauraen got from inspecting the die and the data I had collected from YM2151. Now I can make an operator without hacks. By hacks I mean that in JT51 I had to write some nasty verilog lines to fit the output to the original. JT12 is going to have a much cleaner implementation, with a smaller area footprint.

I think I will have the operator fully working with FM feedback during this coming week. That is the second milestone.

Coming milestones:

-FM feedback in operator and channel accumulator
-Phase generator
-Envelope generator
-Register interface and timers
-PCM output and noise
-Testing
-Release

It will probably take about a week to complete each one of them as I have to work on this on my spare time. Bear with me.

[Gehstock]

[mahen]

Woohoo, great work

[Newsdee]

Tried the core briefly and it's super promising! Keep up the good work!

[vebxenon]

Sound update 29-Jan-2017

I found out this week the correct way of calculating FM feedback combining the information Sauraen got from inspecting the die and the data I had collected from YM2151. Now I can make an operator without hacks. By hacks I mean that in JT51 I had to write some nasty verilog lines to fit the output to the original. JT12 is going to have a much cleaner implementation, with a smaller area footprint.

I think I will have the operator fully working with FM feedback during this coming week. That is the second milestone.

Coming milestones:

-FM feedback in operator and channel accumulator
-Phase generator
-Envelope generator
-Register interface and timers
-PCM output and noise
-Testing
-Release

It will probably take about a week to complete each one of them as I have to work on this on my spare time. Bear with me.

Great!!

[barbaro00]

Wow!! it's impresive. Great work!!

[vebxenon]

Any news on progress?

[Gehstock]

https://github.com/jotego/jt12/tree/656 ... 31/fpgagen

Sound quality is Great but Core Unstable(Loading Error)

[vebxenon]

Wow, outstanding!!!

I'll try it later

[retrorepair]

Wow! This is seriously very cool, thanks to everyone involved and especially jotego for his amazing Yamaha synth models!

[foobar]

Awesome! Can't say how happy I am.

Thank you!

[Gehstock]

This is not my work, thanks must go to jotego and phoboz

[Sheldon]

Very nice, with this core:"clkfeo con warnings.rbf" music is closer than Real Sega Genesis/Megadrive.
There are some glitch and with Sonic game, rings fx are different but wonderful !!!

[Newsdee]

the core file name translates to "ugly clock, with warnings" I shall try this when I get a chance...

[DrOG]

Outstanding result, unfortunately I can not test it now (my MIST is far away, I lent it to my friend, and he didn't bring it back yet). Keep up the good work, have a nice weekend!

[vebxenon]

I tested yesterday the "clk nuevo mio sin warnings.rbf" (Actually I don't know what are the differences between the cores) core. Sound needs still work in pitch, speed and notes, but that's outstanding . Core is still unstable, but wow!

Thanks Phoboz and Jotego!

Regards,

Salva

[lips2k15]

Guys this is great and all but i cant use it as my set up is a 15khz rgb system can somebody please add the scandoubler disabled option to this core?

[retrorepair]

Oh is it not 15khz enabled? That's a shame, I too am using my MIST on a CRT TV.