Gens GS/II

[freq-mod]

To do:

• panning (rn is disabled, couldn't figure that out myself)
• apparently DAC and timer logic
• idk, readme and GUI texts updates

[Wohlstand]

I'll try to help with a panning once I finish my workday after some hours, however, I'll give you some hints on how to backport the soft-panning code:

1) add the pan law table at the top: https://github.com/Wohlstand/OPN2BankEditor/blob/5552cfe6fccd8b3b83eae5a3bb598fab567c77dc/src/opl/chips/gens/Ym2612_Emu.cpp#L259-L282

/*
 * Pan law table
 */
static const unsigned short panlawtable[] =
{
    65535, 65529, 65514, 65489, 65454, 65409, 65354, 65289,
    65214, 65129, 65034, 64929, 64814, 64689, 64554, 64410,
    64255, 64091, 63917, 63733, 63540, 63336, 63123, 62901,
    62668, 62426, 62175, 61914, 61644, 61364, 61075, 60776,
    60468, 60151, 59825, 59489, 59145, 58791, 58428, 58057,
    57676, 57287, 56889, 56482, 56067, 55643, 55211, 54770,
    54320, 53863, 53397, 52923, 52441, 51951, 51453, 50947,
    50433, 49912, 49383, 48846, 48302, 47750, 47191,
    46340, /* Center left */
    46340, /* Center right */
    45472, 44885, 44291, 43690, 43083, 42469, 41848, 41221,
    40588, 39948, 39303, 38651, 37994, 37330, 36661, 35986,
    35306, 34621, 33930, 33234, 32533, 31827, 31116, 30400,
    29680, 28955, 28225, 27492, 26754, 26012, 25266, 24516,
    23762, 23005, 22244, 21480, 20713, 19942, 19169, 18392,
    17613, 16831, 16046, 15259, 14469, 13678, 12884, 12088,
    11291, 10492, 9691, 8888, 8085, 7280, 6473, 5666,
    4858, 4050, 3240, 2431, 1620, 810, 0
};

2) into the channel_t, add two new fields: https://github.com/Wohlstand/OPN2BankEditor/blob/5552cfe6fccd8b3b83eae5a3bb598fab567c77dc/src/opl/chips/gens/Ym2612_Emu.cpp#L99-L100

    int PANVolumeL;         // Left PCM output channel volume
    int PANVolumeR;         // Right PCM output  channel volume

3) Add the public call: https://github.com/Wohlstand/OPN2BankEditor/blob/5552cfe6fccd8b3b83eae5a3bb598fab567c77dc/src/opl/chips/gens/Ym2612_Emu.cpp#L912-L916

void Ym2612_Impl::write_pan( int channel, int data )
{
    YM2612.CHANNEL[channel].PANVolumeL = panlawtable[data & 0x7F];
    YM2612.CHANNEL[channel].PANVolumeR = panlawtable[0x7F - (data & 0x7F)];
}

4) At the reset call, add the set the default values: https://github.com/Wohlstand/OPN2BankEditor/blob/5552cfe6fccd8b3b83eae5a3bb598fab567c77dc/src/opl/chips/gens/Ym2612_Emu.cpp#L948-L949

        ch.PANVolumeL = 46340;
        ch.PANVolumeR = 46340;

5) Into the update channel call, add the formula: https://github.com/Wohlstand/OPN2BankEditor/blob/5552cfe6fccd8b3b83eae5a3bb598fab567c77dc/src/opl/chips/gens/Ym2612_Emu.cpp#L1213-L1214

        int t0 = buf [0] + ((CH_OUTd * ch.PANVolumeL / 65535) & ch.LEFT);
        int t1 = buf [1] + ((CH_OUTd * ch.PANVolumeR / 65535) & ch.RIGHT);

it should do the actual panning. :fox_face: :+1:

[freq-mod]

About the panning, steps 1,2 and 4 went fine, yet 3 and 5... no idea how to do it right into new Gens.

[Wohlstand]

Gonna resume the work on this, I mean, to complete the work you had started on adding of the soft-panning to here.

[Wohlstand]

Okay, I am here, and I am ready to continue this. So, I need to finish the soft-panning code to make it work.

[Wohlstand]

Okay, in the new code you need to inject macros, I did that, now I gonna put this new chipset into libOPNMIDI and verify it's work with the panning...

[Wohlstand]

And, the benchmark ran with the update

[Wohlstand]

Now it's time to try the new MAME core with a BSD license (@jpcima, don't worry, I didn't forgot that :wink:)

[freq-mod]

.... and Nuked OPN-Mod :joy:

[Wohlstand]

.... and Nuked OPN-Mod joy

yeah, also, @nukeykt thinks about making the real OPNA emulator which will represent the original OPNA internal logic.

[freq-mod]

, @nukeykt thinks about making the real OPNA emulator which will represent the original OPNA internal logic.

wow, for real? finally, proper OPNA emulation, after 22+ years of development...

[Wohlstand]

Recently he made the accurate OPM emulator https://github.com/nukeykt/Nuked-OPM and we discussed its work, he showed me various things against it.