sound.js

// sound emulation routines for EstyJs
// written by Darren Coles - taken from jsspeccy routines (with modifications)_

// Sound routines for jsspeccy
// General sound routines and 48k buzzer emulation written by Darren Coles
// 128k Spectrum sound routines developed from DelphiSpec emulator (credits below).
// (c) 2013 Darren Coles
//
// Credits from DelphiSpec:
//
//  Routines for emulating the 128K Spectrum's AY-3-8912 sound generator
//
//  Author: James Bagg <chipmunk_uk_1@hotmail.com>
//
//   With minor optimisations and mods by
//           Chris Cowley <ccowley@grok.co.uk>
//
//   Translation to Delphi Object Pascal by
//           Jari Korhonen <jarit.korhonen@luukku.com>
//
//   Copyright (C)1999-2000 Grok Developments Ltd  and James Bagg
//   http://www.grok.co.uk/      http://www.chipmunks-corner.co.uk
//   This program is free software; you can redistribute it and/or
//   modify it under the terms of the GNU General Public License
//   as published by the Free Software Foundation; either version 2
//   of the License, or (at your option) any later version.
//   This program is distributed in the hope that it will be useful,
//   but WITHOUT ANY WARRANTY; without even the implied warranty of
//   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See thes
//   GNU General Public License for more details.
//
//   You should have received a copy of the GNU General Public License
//   along with this program; if not, write to the Free Software
//   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
//
// *******************************************************************************/

"use strict";

EstyJs.Sound = function (opts) {
    var self = {};

    var audioContext = null;
    var audioNode = null;

    var bug = opts.bug;

    var fdc = opts.fdc;

    var clock = 512 * 313 * 50 / 4;

    var samplesPerFrame = 882;
    var sampleRate = samplesPerFrame * 50;

    var audioOutput = null;
    var audioBuffer = null;
    var audioBuffer2 = null;

    var soundEnabled = true;

    var regSelect = 0;

    var soundDataFrameBytes = 0;

    var frameCount = 0;
    var rowCount = 0;

    var processor = null;

    var WCount = 0;
    var lCounter = 0;

    var lastWritten = new Date();

    //ay stuff
    var MAX_OUTPUT = 63;
    var AY_STEP = 32768;
    var MAXVOL = 31;

    // AY register ID's
    var AY_AFINE = 0;
    var AY_ACOARSE = 1;
    var AY_BFINE = 2;
    var AY_BCOARSE = 3;
    var AY_CFINE = 4;
    var AY_CCOARSE = 5;
    var AY_NOISEPER = 6;
    var AY_ENABLE = 7;
    var AY_AVOL = 8;
    var AY_BVOL = 9;
    var AY_CVOL = 10;
    var AY_EFINE = 11;
    var AY_ECOARSE = 12;
    var AY_ESHAPE = 13;
    var AY_PORTA = 14;
    var AY_PORTB = 15;

    //var RegArray = new Int32Array(16);
    //var VolTableArray 

    var AY8912_sampleRate = 0;
    var AY8912_register_latch = 0;
    var AY8912_Regs = new Int32Array(16);
    var AY8912_UpdateStep = 0; //Double;
    var AY8912_PeriodA = 0;
    var AY8912_PeriodB = 0;
    var AY8912_PeriodC = 0;
    var AY8912_PeriodN = 0;
    var AY8912_PeriodE = 0;
    var AY8912_CountA = 0;
    var AY8912_CountB = 0;
    var AY8912_CountC = 0;
    var AY8912_CountN = 0;
    var AY8912_CountE = 0;
    var AY8912_VolA = 0;
    var AY8912_VolB = 0;
    var AY8912_VolC = 0;
    var AY8912_VolE = 0;
    var AY8912_EnvelopeA = 0;
    var AY8912_EnvelopeB = 0;
    var AY8912_EnvelopeC = 0;
    var AY8912_OutputA = 0;
    var AY8912_OutputB = 0;
    var AY8912_OutputC = 0;
    var AY8912_OutputN = 0;
    var AY8912_CountEnv = 0;
    var AY8912_Hold = 0;
    var AY8912_Alternate = 0;
    var AY8912_Attack = 0;
    var AY8912_Holding = 0;

    var AY_OutNoise = 0;


    /**
    * Sixteen level by Three voice YM2149 volume_table[C][B][A]
    * This file is #include'd in sound.c
    * Data measured by Paulo Simoes. Copyright 2012 Paulo Simoes.
    *
    * Note that Hatari only uses the ST Replay table because Hatari
    * indexes 'one less' into the Replay table when Quartet values
    * are needed. This allows any voice to be Quartet or Replay,
    * independent of the others. Geometric mean interpolation is
    * used to expand this 16*16*16 table to 32*32*32.
    */
    var volTable =

 [
  [
  [0, 120, 251, 385, 598, 840, 1258, 1725, 2536, 3483, 5151, 7054, 10367, 14634, 22931, 34469],
  [120, 283, 419, 556, 771, 1009, 1433, 1894, 2702, 3645, 5310, 7207, 10508, 14757, 23015, 34480],
  [251, 419, 553, 692, 903, 1147, 1565, 2026, 2833, 3775, 5439, 7325, 10619, 14857, 23082, 34493],
  [385, 556, 692, 828, 1038, 1286, 1704, 2164, 2967, 3906, 5564, 7450, 10733, 14958, 23156, 34509],
  [598, 771, 903, 1038, 1261, 1502, 1925, 2382, 3176, 4113, 5764, 7649, 10915, 15123, 23272, 34538],
  [840, 1009, 1147, 1286, 1502, 1747, 2167, 2626, 3417, 4348, 5985, 7851, 11109, 15302, 23400, 34570],
  [1258, 1433, 1565, 1704, 1925, 2167, 2572, 3019, 3812, 4743, 6367, 8205, 11457, 15616, 23639, 34646],
  [1725, 1894, 2026, 2164, 2382, 2626, 3019, 3487, 4266, 5173, 6792, 8517, 11852, 15979, 23925, 34754],
  [2536, 2702, 2833, 2967, 3176, 3417, 3812, 4266, 5048, 5947, 7542, 9227, 12543, 16613, 24440, 34992],
  [3483, 3645, 3775, 3906, 4113, 4348, 4743, 5173, 5947, 6847, 8353, 10089, 13357, 17288, 25084, 35355],
  [5151, 5310, 5439, 5564, 5764, 5985, 6367, 6792, 7542, 8353, 9780, 11549, 14769, 18591, 26237, 36119],
  [7054, 7207, 7325, 7450, 7649, 7851, 8205, 8517, 9227, 10089, 11549, 13292, 16452, 20206, 27628, 37143],
  [10367, 10508, 10619, 10733, 10915, 11109, 11457, 11852, 12543, 13357, 14769, 16452, 19431, 23228, 30481, 39499],
  [14634, 14757, 14857, 14958, 15123, 15302, 15616, 15979, 16613, 17288, 18591, 20206, 23228, 26871, 34097, 42635],
  [22931, 23015, 23082, 23156, 23272, 23400, 23639, 23925, 24440, 25084, 26237, 27628, 30481, 34097, 40524, 48336],
  [34469, 34480, 34493, 34509, 34538, 34570, 34646, 34754, 34992, 35355, 36119, 37143, 39499, 42635, 48336, 55377]
  ],
  [
  [120, 283, 419, 556, 771, 1009, 1433, 1894, 2702, 3645, 5310, 7207, 10508, 14757, 23015, 34480],
  [283, 453, 589, 723, 941, 1179, 1601, 2059, 2864, 3811, 5472, 7358, 10646, 14884, 23101, 34500],
  [419, 589, 727, 863, 1077, 1316, 1737, 2194, 2998, 3938, 5599, 7478, 10755, 14980, 23168, 34509],
  [556, 723, 863, 997, 1212, 1453, 1874, 2331, 3130, 4067, 5726, 7602, 10872, 15084, 23243, 34526],
  [771, 941, 1077, 1212, 1427, 1674, 2089, 2551, 3345, 4273, 5916, 7792, 11056, 15245, 23354, 34556],
  [1009, 1179, 1316, 1453, 1674, 1915, 2333, 2788, 3579, 4509, 6142, 7993, 11249, 15426, 23486, 34585],
  [1433, 1601, 1737, 1874, 2089, 2333, 2735, 3188, 3976, 4898, 6516, 8315, 11594, 15735, 23718, 34662],
  [1894, 2059, 2194, 2331, 2551, 2788, 3188, 3649, 4423, 5330, 6948, 8656, 11984, 16094, 24004, 34771],
  [2702, 2864, 2998, 3130, 3345, 3579, 3976, 4423, 5202, 6104, 7684, 9368, 12668, 16724, 24512, 35007],
  [3645, 3811, 3938, 4067, 4273, 4509, 4898, 5330, 6104, 6999, 8449, 10221, 13483, 17379, 25149, 35366],
  [5310, 5472, 5599, 5726, 5916, 6142, 6516, 6948, 7684, 8449, 9917, 11680, 14885, 18689, 26297, 36126],
  [7207, 7358, 7478, 7602, 7792, 7993, 8315, 8656, 9368, 10221, 11680, 13417, 16558, 20295, 27677, 37144],
  [10508, 10646, 10755, 10872, 11056, 11249, 11594, 11984, 12668, 13483, 14885, 16558, 19523, 23300, 30508, 39500],
  [14757, 14884, 14980, 15084, 15245, 15426, 15735, 16094, 16724, 17379, 18689, 20295, 23300, 26918, 34108, 42636],
  [23015, 23101, 23168, 23243, 23354, 23486, 23718, 24004, 24512, 25149, 26297, 27677, 30508, 34108, 40527, 48337],
  [34480, 34500, 34509, 34526, 34556, 34585, 34662, 34771, 35007, 35366, 36126, 37144, 39500, 42636, 48337, 55377]
  ],
  [
  [251, 419, 553, 692, 903, 1147, 1565, 2026, 2833, 3775, 5439, 7325, 10619, 14857, 23082, 34493],
  [419, 589, 727, 863, 1077, 1316, 1737, 2194, 2998, 3938, 5599, 7478, 10755, 14980, 23168, 34509],
  [553, 727, 863, 999, 1213, 1454, 1873, 2329, 3129, 4071, 5727, 7600, 10871, 15085, 23243, 34524],
  [692, 863, 999, 1135, 1351, 1592, 2011, 2466, 3264, 4199, 5849, 7724, 10990, 15187, 23315, 34541],
  [903, 1077, 1213, 1351, 1567, 1811, 2230, 2689, 3476, 4402, 6041, 7910, 11165, 15342, 23425, 34568],
  [1147, 1316, 1454, 1592, 1811, 2054, 2469, 2924, 3716, 4640, 6265, 8109, 11365, 15526, 23554, 34601],
  [1565, 1737, 1873, 2011, 2230, 2469, 2873, 3323, 4105, 5023, 6639, 8395, 11700, 15831, 23786, 34675],
  [2026, 2194, 2329, 2466, 2689, 2924, 3323, 3777, 4553, 5456, 7069, 8770, 12097, 16188, 24070, 34781],
  [2833, 2998, 3129, 3264, 3476, 3716, 4105, 4553, 5330, 6231, 7804, 9480, 12776, 16820, 24574, 35020],
  [3775, 3938, 4071, 4199, 4402, 4640, 5023, 5456, 6231, 7115, 8554, 10329, 13586, 17460, 25207, 35381],
  [5439, 5599, 5727, 5849, 6041, 6265, 6639, 7069, 7804, 8554, 10029, 11784, 14980, 18770, 26344, 36134],
  [7325, 7478, 7600, 7724, 7910, 8109, 8395, 8770, 9480, 10329, 11784, 13519, 16643, 20370, 27719, 37151],
  [10619, 10755, 10871, 10990, 11165, 11365, 11700, 12097, 12776, 13586, 14980, 16643, 19601, 23359, 30533, 39501],
  [14857, 14980, 15085, 15187, 15342, 15526, 15831, 16188, 16820, 17460, 18770, 20370, 23359, 26957, 34125, 42637],
  [23082, 23168, 23243, 23315, 23425, 23554, 23786, 24070, 24574, 25207, 26344, 27719, 30533, 34125, 40529, 48338],
  [34493, 34509, 34524, 34541, 34568, 34601, 34675, 34781, 35020, 35381, 36134, 37151, 39501, 42637, 48338, 55378]
  ],
  [
  [385, 556, 692, 828, 1038, 1286, 1704, 2164, 2967, 3906, 5564, 7450, 10733, 14958, 23156, 34509],
  [556, 723, 863, 997, 1212, 1453, 1874, 2331, 3130, 4067, 5726, 7602, 10872, 15084, 23243, 34526],
  [692, 863, 999, 1135, 1351, 1592, 2011, 2466, 3264, 4199, 5849, 7724, 10990, 15187, 23315, 34541],
  [828, 997, 1135, 1276, 1482, 1731, 2146, 2605, 3397, 4324, 5970, 7841, 11105, 15285, 23389, 34561],
  [1038, 1212, 1351, 1482, 1703, 1945, 2363, 2819, 3606, 4535, 6167, 8026, 11271, 15445, 23493, 34587],
  [1286, 1453, 1592, 1731, 1945, 2185, 2605, 3053, 3844, 4769, 6395, 8222, 11476, 15625, 23625, 34620],
  [1704, 1874, 2011, 2146, 2363, 2605, 3004, 3452, 4232, 5154, 6762, 8488, 11803, 15932, 23851, 34692],
  [2164, 2331, 2466, 2605, 2819, 3053, 3452, 3909, 4682, 5580, 7190, 8888, 12204, 16280, 24134, 34798],
  [2967, 3130, 3264, 3397, 3606, 3844, 4232, 4682, 5456, 6350, 7915, 9593, 12882, 16907, 24637, 35034],
  [3906, 4067, 4199, 4324, 4535, 4769, 5154, 5580, 6350, 7235, 8667, 10439, 13680, 17548, 25267, 35392],
  [5564, 5726, 5849, 5970, 6167, 6395, 6762, 7190, 7915, 8667, 10135, 11887, 15073, 18851, 26391, 36142],
  [7450, 7602, 7724, 7841, 8026, 8222, 8488, 8888, 9593, 10439, 11887, 13620, 16729, 20446, 27762, 37157],
  [10733, 10872, 10990, 11105, 11271, 11476, 11803, 12204, 12882, 13680, 15073, 16729, 19676, 23419, 30559, 39503],
  [14958, 15084, 15187, 15285, 15445, 15625, 15932, 16280, 16907, 17548, 18851, 20446, 23419, 26998, 34139, 42639],
  [23156, 23243, 23315, 23389, 23493, 23625, 23851, 24134, 24637, 25267, 26391, 27762, 30559, 34139, 40534, 48339],
  [34509, 34526, 34541, 34561, 34587, 34620, 34692, 34798, 35034, 35392, 36142, 37157, 39503, 42639, 48339, 55378]
  ],
  [
  [598, 771, 903, 1038, 1261, 1502, 1925, 2382, 3176, 4113, 5764, 7649, 10915, 15123, 23272, 34538],
  [771, 941, 1077, 1212, 1427, 1674, 2089, 2551, 3345, 4273, 5916, 7792, 11056, 15245, 23354, 34556],
  [903, 1077, 1213, 1351, 1567, 1811, 2230, 2689, 3476, 4402, 6041, 7910, 11165, 15342, 23425, 34568],
  [1038, 1212, 1351, 1482, 1703, 1945, 2363, 2819, 3606, 4535, 6167, 8026, 11271, 15445, 23493, 34587],
  [1261, 1427, 1567, 1703, 1916, 2162, 2575, 3032, 3817, 4738, 6364, 8201, 11449, 15605, 23608, 34613],
  [1502, 1674, 1811, 1945, 2162, 2399, 2817, 3263, 4051, 4974, 6588, 8362, 11657, 15784, 23741, 34649],
  [1925, 2089, 2230, 2363, 2575, 2817, 3212, 3664, 4440, 5348, 6954, 8660, 11979, 16087, 23965, 34720],
  [2382, 2551, 2689, 2819, 3032, 3263, 3664, 4111, 4880, 5781, 7385, 9072, 12371, 16431, 24240, 34823],
  [3176, 3345, 3476, 3606, 3817, 4051, 4440, 4880, 5653, 6548, 8104, 9776, 13045, 17045, 24740, 35060],
  [4113, 4273, 4402, 4535, 4738, 4974, 5348, 5781, 6548, 7426, 8845, 10614, 13842, 17683, 25362, 35414],
  [5764, 5916, 6041, 6167, 6364, 6588, 6954, 7385, 8104, 8845, 10314, 12061, 15219, 18983, 26463, 36154],
  [7649, 7792, 7910, 8026, 8201, 8362, 8660, 9072, 9776, 10614, 12061, 13783, 16862, 20567, 27833, 37166],
  [10915, 11056, 11165, 11271, 11449, 11657, 11979, 12371, 13045, 13842, 15219, 16862, 19799, 23517, 30606, 39513],
  [15123, 15245, 15342, 15445, 15605, 15784, 16087, 16431, 17045, 17683, 18983, 20567, 23517, 27066, 34164, 42641],
  [23272, 23354, 23425, 23493, 23608, 23741, 23965, 24240, 24740, 25362, 26463, 27833, 30606, 34164, 40537, 48340],
  [34538, 34556, 34568, 34587, 34613, 34649, 34720, 34823, 35060, 35414, 36154, 37166, 39513, 42641, 48340, 55379]
  ],
  [
  [840, 1009, 1147, 1286, 1502, 1747, 2167, 2626, 3417, 4348, 5985, 7851, 11109, 15302, 23400, 34570],
  [1009, 1179, 1316, 1453, 1674, 1915, 2333, 2788, 3579, 4509, 6142, 7993, 11249, 15426, 23486, 34585],
  [1147, 1316, 1454, 1592, 1811, 2054, 2469, 2924, 3716, 4640, 6265, 8109, 11365, 15526, 23554, 34601],
  [1286, 1453, 1592, 1731, 1945, 2185, 2605, 3053, 3844, 4769, 6395, 8222, 11476, 15625, 23625, 34620],
  [1502, 1674, 1811, 1945, 2162, 2399, 2817, 3263, 4051, 4974, 6588, 8362, 11657, 15784, 23741, 34649],
  [1747, 1915, 2054, 2185, 2399, 2640, 3054, 3501, 4282, 5198, 6806, 8530, 11855, 15961, 23871, 34688],
  [2167, 2333, 2469, 2605, 2817, 3054, 3449, 3898, 4667, 5571, 7172, 8864, 12172, 16261, 24094, 34758],
  [2626, 2788, 2924, 3053, 3263, 3501, 3898, 4342, 5110, 6002, 7594, 9274, 12564, 16600, 24361, 34858],
  [3417, 3579, 3716, 3844, 4051, 4282, 4667, 5110, 5878, 6764, 8289, 9978, 13233, 17183, 24857, 35090],
  [4348, 4509, 4640, 4769, 4974, 5198, 5571, 6002, 6764, 7634, 9046, 10809, 14023, 17843, 25474, 35441],
  [5985, 6142, 6265, 6395, 6588, 6806, 7172, 7594, 8289, 9046, 10510, 12249, 15389, 19129, 26571, 36174],
  [7851, 7993, 8109, 8222, 8362, 8530, 8864, 9274, 9978, 10809, 12249, 13962, 17018, 20703, 27915, 37183],
  [11109, 11249, 11365, 11476, 11657, 11855, 12172, 12564, 13233, 14023, 15389, 17018, 19935, 23632, 30665, 39517],
  [15302, 15426, 15526, 15625, 15784, 15961, 16261, 16600, 17183, 17843, 19129, 20703, 23632, 27149, 34193, 42643],
  [23400, 23486, 23554, 23625, 23741, 23871, 24094, 24361, 24857, 25474, 26571, 27915, 30665, 34193, 40540, 48341],
  [34570, 34585, 34601, 34620, 34649, 34688, 34758, 34858, 35090, 35441, 36174, 37183, 39517, 42643, 48341, 55379]
  ],
  [
  [1258, 1433, 1565, 1704, 1925, 2167, 2572, 3019, 3812, 4743, 6367, 8205, 11457, 15616, 23639, 34646],
  [1433, 1601, 1737, 1874, 2089, 2333, 2735, 3188, 3976, 4898, 6516, 8315, 11594, 15735, 23718, 34662],
  [1565, 1737, 1873, 2011, 2230, 2469, 2873, 3323, 4105, 5023, 6639, 8395, 11700, 15831, 23786, 34675],
  [1704, 1874, 2011, 2146, 2363, 2605, 3004, 3452, 4232, 5154, 6762, 8488, 11803, 15932, 23851, 34692],
  [1925, 2089, 2230, 2363, 2575, 2817, 3212, 3664, 4440, 5348, 6954, 8660, 11979, 16087, 23965, 34720],
  [2167, 2333, 2469, 2605, 2817, 3054, 3449, 3898, 4667, 5571, 7172, 8864, 12172, 16261, 24094, 34758],
  [2572, 2735, 2873, 3004, 3212, 3449, 3854, 4302, 5067, 5961, 7550, 9224, 12519, 16573, 24328, 34836],
  [3019, 3188, 3323, 3452, 3664, 3898, 4302, 4742, 5503, 6387, 7962, 9634, 12895, 16899, 24587, 34932],
  [3812, 3976, 4105, 4232, 4440, 4667, 5067, 5503, 6267, 7143, 8571, 10335, 13563, 17414, 25071, 35162],
  [4743, 4898, 5023, 5154, 5348, 5571, 5961, 6387, 7143, 8004, 9406, 11158, 14338, 18124, 25673, 35504],
  [6367, 6516, 6639, 6762, 6954, 7172, 7550, 7962, 8571, 9406, 10856, 12580, 15691, 19396, 26692, 36217],
  [8205, 8315, 8395, 8488, 8660, 8864, 9224, 9634, 10335, 11158, 12580, 14275, 17244, 20952, 28071, 37216],
  [11457, 11594, 11700, 11803, 11979, 12172, 12519, 12895, 13563, 14338, 15691, 17244, 20186, 23839, 30781, 39535],
  [15616, 15735, 15831, 15932, 16087, 16261, 16573, 16899, 17414, 18124, 19396, 20952, 23839, 27307, 34258, 42647],
  [23639, 23718, 23786, 23851, 23965, 24094, 24328, 24587, 25071, 25673, 26692, 28071, 30781, 34258, 40553, 48342],
  [34646, 34662, 34675, 34692, 34720, 34758, 34836, 34932, 35162, 35504, 36217, 37216, 39535, 42647, 48342, 55380]
  ],
  [
  [1725, 1894, 2026, 2164, 2382, 2626, 3019, 3487, 4266, 5173, 6792, 8517, 11852, 15979, 23925, 34754],
  [1894, 2059, 2194, 2331, 2551, 2788, 3188, 3649, 4423, 5330, 6948, 8656, 11984, 16094, 24004, 34771],
  [2026, 2194, 2329, 2466, 2689, 2924, 3323, 3777, 4553, 5456, 7069, 8770, 12097, 16188, 24070, 34781],
  [2164, 2331, 2466, 2605, 2819, 3053, 3452, 3909, 4682, 5580, 7190, 8888, 12204, 16280, 24134, 34798],
  [2382, 2551, 2689, 2819, 3032, 3263, 3664, 4111, 4880, 5781, 7385, 9072, 12371, 16431, 24240, 34823],
  [2626, 2788, 2924, 3053, 3263, 3501, 3898, 4342, 5110, 6002, 7594, 9274, 12564, 16600, 24361, 34858],
  [3019, 3188, 3323, 3452, 3664, 3898, 4302, 4742, 5503, 6387, 7962, 9634, 12895, 16899, 24587, 34932],
  [3487, 3649, 3777, 3909, 4111, 4342, 4742, 5177, 5934, 6818, 8332, 10028, 13268, 17198, 24845, 35038],
  [4266, 4423, 4553, 4682, 4880, 5110, 5503, 5934, 6687, 7559, 8964, 10727, 13927, 17732, 25320, 35258],
  [5173, 5330, 5456, 5580, 5781, 6002, 6387, 6818, 7559, 8353, 9797, 11537, 14695, 18443, 25905, 35591],
  [6792, 6948, 7069, 7190, 7385, 7594, 7962, 8332, 8964, 9797, 11242, 12949, 16028, 19695, 26891, 36270],
  [8517, 8656, 8770, 8888, 9072, 9274, 9634, 10028, 10727, 11537, 12949, 14625, 17520, 21231, 28260, 37278],
  [11852, 11984, 12097, 12204, 12371, 12564, 12895, 13268, 13927, 14695, 16028, 17520, 20469, 24080, 30926, 39567],
  [15979, 16094, 16188, 16280, 16431, 16600, 16899, 17198, 17732, 18443, 19695, 21231, 24080, 27498, 34345, 42662],
  [23925, 24004, 24070, 24134, 24240, 24361, 24587, 24845, 25320, 25905, 26891, 28260, 30926, 34345, 40575, 48344],
  [34754, 34771, 34781, 34798, 34823, 34858, 34932, 35038, 35258, 35591, 36270, 37278, 39567, 42662, 48344, 55381]
  ],
  [
  [2536, 2702, 2833, 2967, 3176, 3417, 3812, 4266, 5048, 5947, 7542, 9227, 12543, 16613, 24440, 34992],
  [2702, 2864, 2998, 3130, 3345, 3579, 3976, 4423, 5202, 6104, 7684, 9368, 12668, 16724, 24512, 35007],
  [2833, 2998, 3129, 3264, 3476, 3716, 4105, 4553, 5330, 6231, 7804, 9480, 12776, 16820, 24574, 35020],
  [2967, 3130, 3264, 3397, 3606, 3844, 4232, 4682, 5456, 6350, 7915, 9593, 12882, 16907, 24637, 35034],
  [3176, 3345, 3476, 3606, 3817, 4051, 4440, 4880, 5653, 6548, 8104, 9776, 13045, 17045, 24740, 35060],
  [3417, 3579, 3716, 3844, 4051, 4282, 4667, 5110, 5878, 6764, 8289, 9978, 13233, 17183, 24857, 35090],
  [3812, 3976, 4105, 4232, 4440, 4667, 5067, 5503, 6267, 7143, 8571, 10335, 13563, 17414, 25071, 35162],
  [4266, 4423, 4553, 4682, 4880, 5110, 5503, 5934, 6687, 7559, 8964, 10727, 13927, 17732, 25320, 35258],
  [5048, 5202, 5330, 5456, 5653, 5878, 6267, 6687, 7432, 8260, 9665, 11412, 14575, 18313, 25781, 35482],
  [5947, 6104, 6231, 6350, 6548, 6764, 7143, 7559, 8260, 8997, 10490, 12209, 15324, 19011, 26331, 35795],
  [7542, 7684, 7804, 7915, 8104, 8289, 8571, 8964, 9665, 10490, 11913, 13590, 16629, 20233, 27289, 36423],
  [9227, 9368, 9480, 9593, 9776, 9978, 10335, 10727, 11412, 12209, 13590, 15237, 18080, 21736, 28624, 37418],
  [12543, 12668, 12776, 12882, 13045, 13233, 13563, 13927, 14575, 15324, 16629, 18080, 20977, 24523, 31218, 39649],
  [16613, 16724, 16820, 16907, 17045, 17183, 17414, 17732, 18313, 19011, 20233, 21736, 24523, 27863, 34544, 42695],
  [24440, 24512, 24574, 24637, 24740, 24857, 25071, 25320, 25781, 26331, 27289, 28624, 31218, 34544, 40634, 48348],
  [34992, 35007, 35020, 35034, 35060, 35090, 35162, 35258, 35482, 35795, 36423, 37418, 39649, 42695, 48348, 55382]
  ],
  [
  [3483, 3645, 3775, 3906, 4113, 4348, 4743, 5173, 5947, 6847, 8353, 10089, 13357, 17288, 25084, 35355],
  [3645, 3811, 3938, 4067, 4273, 4509, 4898, 5330, 6104, 6999, 8449, 10221, 13483, 17379, 25149, 35366],
  [3775, 3938, 4071, 4199, 4402, 4640, 5023, 5456, 6231, 7115, 8554, 10329, 13586, 17460, 25207, 35381],
  [3906, 4067, 4199, 4324, 4535, 4769, 5154, 5580, 6350, 7235, 8667, 10439, 13680, 17548, 25267, 35392],
  [4113, 4273, 4402, 4535, 4738, 4974, 5348, 5781, 6548, 7426, 8845, 10614, 13842, 17683, 25362, 35414],
  [4348, 4509, 4640, 4769, 4974, 5198, 5571, 6002, 6764, 7634, 9046, 10809, 14023, 17843, 25474, 35441],
  [4743, 4898, 5023, 5154, 5348, 5571, 5961, 6387, 7143, 8004, 9406, 11158, 14338, 18124, 25673, 35504],
  [5173, 5330, 5456, 5580, 5781, 6002, 6387, 6818, 7559, 8353, 9797, 11537, 14695, 18443, 25905, 35591],
  [5947, 6104, 6231, 6350, 6548, 6764, 7143, 7559, 8260, 8997, 10490, 12209, 15324, 19011, 26331, 35795],
  [6847, 6999, 7115, 7235, 7426, 7634, 8004, 8353, 8997, 9829, 11306, 12998, 16067, 19696, 26808, 36099],
  [8353, 8449, 8554, 8667, 8845, 9046, 9406, 9797, 10490, 11306, 12706, 14348, 17258, 20884, 27805, 36672],
  [10089, 10221, 10329, 10439, 10614, 10809, 11158, 11537, 12209, 12998, 14348, 15967, 18756, 22352, 29098, 37647],
  [13357, 13483, 13586, 13680, 13842, 14023, 14338, 14695, 15324, 16067, 17258, 18756, 21599, 25072, 31613, 39810],
  [17288, 17379, 17460, 17548, 17683, 17843, 18124, 18443, 19011, 19696, 20884, 22352, 25072, 28332, 34841, 42772],
  [25084, 25149, 25207, 25267, 25362, 25474, 25673, 25905, 26331, 26808, 27805, 29098, 31613, 34841, 40758, 48353],
  [35355, 35366, 35381, 35392, 35414, 35441, 35504, 35591, 35795, 36099, 36672, 37647, 39810, 42772, 48353, 55383]
  ],
  [
  [5151, 5310, 5439, 5564, 5764, 5985, 6367, 6792, 7542, 8353, 9780, 11549, 14769, 18591, 26237, 36119],
  [5310, 5472, 5599, 5726, 5916, 6142, 6516, 6948, 7684, 8449, 9917, 11680, 14885, 18689, 26297, 36126],
  [5439, 5599, 5727, 5849, 6041, 6265, 6639, 7069, 7804, 8554, 10029, 11784, 14980, 18770, 26344, 36134],
  [5564, 5726, 5849, 5970, 6167, 6395, 6762, 7190, 7915, 8667, 10135, 11887, 15073, 18851, 26391, 36142],
  [5764, 5916, 6041, 6167, 6364, 6588, 6954, 7385, 8104, 8845, 10314, 12061, 15219, 18983, 26463, 36154],
  [5985, 6142, 6265, 6395, 6588, 6806, 7172, 7594, 8289, 9046, 10510, 12249, 15389, 19129, 26571, 36174],
  [6367, 6516, 6639, 6762, 6954, 7172, 7550, 7962, 8571, 9406, 10856, 12580, 15691, 19396, 26692, 36217],
  [6792, 6948, 7069, 7190, 7385, 7594, 7962, 8332, 8964, 9797, 11242, 12949, 16028, 19695, 26891, 36270],
  [7542, 7684, 7804, 7915, 8104, 8289, 8571, 8964, 9665, 10490, 11913, 13590, 16629, 20233, 27289, 36423],
  [8353, 8449, 8554, 8667, 8845, 9046, 9406, 9797, 10490, 11306, 12706, 14348, 17258, 20884, 27805, 36672],
  [9780, 9917, 10029, 10135, 10314, 10510, 10856, 11242, 11913, 12706, 14111, 15703, 18497, 22076, 28804, 37321],
  [11549, 11680, 11784, 11887, 12061, 12249, 12580, 12949, 13590, 14348, 15703, 17212, 19984, 23485, 30030, 38230],
  [14769, 14885, 14980, 15073, 15219, 15389, 15691, 16028, 16629, 17258, 18497, 19984, 22737, 26094, 32422, 40256],
  [18591, 18689, 18770, 18851, 18983, 19129, 19396, 19695, 20233, 20884, 22076, 23485, 26094, 29241, 35499, 43067],
  [26237, 26297, 26344, 26391, 26463, 26571, 26692, 26891, 27289, 27805, 28804, 30030, 32422, 35499, 41131, 48449],
  [36119, 36126, 36134, 36142, 36154, 36174, 36217, 36270, 36423, 36672, 37321, 38230, 40256, 43067, 48449, 55385]
  ],
  [
  [7054, 7207, 7325, 7450, 7649, 7851, 8205, 8517, 9227, 10089, 11549, 13292, 16452, 20206, 27628, 37143],
  [7207, 7358, 7478, 7602, 7792, 7993, 8315, 8656, 9368, 10221, 11680, 13417, 16558, 20295, 27677, 37144],
  [7325, 7478, 7600, 7724, 7910, 8109, 8395, 8770, 9480, 10329, 11784, 13519, 16643, 20370, 27719, 37151],
  [7450, 7602, 7724, 7841, 8026, 8222, 8488, 8888, 9593, 10439, 11887, 13620, 16729, 20446, 27762, 37157],
  [7649, 7792, 7910, 8026, 8201, 8362, 8660, 9072, 9776, 10614, 12061, 13783, 16862, 20567, 27833, 37166],
  [7851, 7993, 8109, 8222, 8362, 8530, 8864, 9274, 9978, 10809, 12249, 13962, 17018, 20703, 27915, 37183],
  [8205, 8315, 8395, 8488, 8660, 8864, 9224, 9634, 10335, 11158, 12580, 14275, 17244, 20952, 28071, 37216],
  [8517, 8656, 8770, 8888, 9072, 9274, 9634, 10028, 10727, 11537, 12949, 14625, 17520, 21231, 28260, 37278],
  [9227, 9368, 9480, 9593, 9776, 9978, 10335, 10727, 11412, 12209, 13590, 15237, 18080, 21736, 28624, 37418],
  [10089, 10221, 10329, 10439, 10614, 10809, 11158, 11537, 12209, 12998, 14348, 15967, 18756, 22352, 29098, 37647],
  [11549, 11680, 11784, 11887, 12061, 12249, 12580, 12949, 13590, 14348, 15703, 17212, 19984, 23485, 30030, 38230],
  [13292, 13417, 13519, 13620, 13783, 13962, 14275, 14625, 15237, 15967, 17212, 18672, 21436, 24840, 31211, 39115],
  [16452, 16558, 16643, 16729, 16862, 17018, 17244, 17520, 18080, 18756, 19984, 21436, 24097, 27224, 33479, 40993],
  [20206, 20295, 20370, 20446, 20567, 20703, 20952, 21231, 21736, 22352, 23485, 24840, 27224, 30386, 36330, 43638],
  [27628, 27677, 27719, 27762, 27833, 27915, 28071, 28260, 28624, 29098, 30030, 31211, 33479, 36330, 41775, 48724],
  [37143, 37144, 37151, 37157, 37166, 37183, 37216, 37278, 37418, 37647, 38230, 39115, 40993, 43638, 48724, 55407]
  ],
  [
  [10367, 10508, 10619, 10733, 10915, 11109, 11457, 11852, 12543, 13357, 14769, 16452, 19431, 23228, 30481, 39499],
  [10508, 10646, 10755, 10872, 11056, 11249, 11594, 11984, 12668, 13483, 14885, 16558, 19523, 23300, 30508, 39500],
  [10619, 10755, 10871, 10990, 11165, 11365, 11700, 12097, 12776, 13586, 14980, 16643, 19601, 23359, 30533, 39501],
  [10733, 10872, 10990, 11105, 11271, 11476, 11803, 12204, 12882, 13680, 15073, 16729, 19676, 23419, 30559, 39503],
  [10915, 11056, 11165, 11271, 11449, 11657, 11979, 12371, 13045, 13842, 15219, 16862, 19799, 23517, 30606, 39513],
  [11109, 11249, 11365, 11476, 11657, 11855, 12172, 12564, 13233, 14023, 15389, 17018, 19935, 23632, 30665, 39517],
  [11457, 11594, 11700, 11803, 11979, 12172, 12519, 12895, 13563, 14338, 15691, 17244, 20186, 23839, 30781, 39535],
  [11852, 11984, 12097, 12204, 12371, 12564, 12895, 13268, 13927, 14695, 16028, 17520, 20469, 24080, 30926, 39567],
  [12543, 12668, 12776, 12882, 13045, 13233, 13563, 13927, 14575, 15324, 16629, 18080, 20977, 24523, 31218, 39649],
  [13357, 13483, 13586, 13680, 13842, 14023, 14338, 14695, 15324, 16067, 17258, 18756, 21599, 25072, 31613, 39810],
  [14769, 14885, 14980, 15073, 15219, 15389, 15691, 16028, 16629, 17258, 18497, 19984, 22737, 26094, 32422, 40256],
  [16452, 16558, 16643, 16729, 16862, 17018, 17244, 17520, 18080, 18756, 19984, 21436, 24097, 27224, 33479, 40993],
  [19431, 19523, 19601, 19676, 19799, 19935, 20186, 20469, 20977, 21599, 22737, 24097, 26557, 29604, 35584, 42710],
  [23228, 23300, 23359, 23419, 23517, 23632, 23839, 24080, 24523, 25072, 26094, 27224, 29604, 32602, 38145, 45081],
  [30481, 30508, 30533, 30559, 30606, 30665, 30781, 30926, 31218, 31613, 32422, 33479, 35584, 38145, 43319, 49733],
  [39499, 39500, 39501, 39503, 39513, 39517, 39535, 39567, 39649, 39810, 40256, 40993, 42710, 45081, 49733, 55763]
  ],
  [
  [14634, 14757, 14857, 14958, 15123, 15302, 15616, 15979, 16613, 17288, 18591, 20206, 23228, 26871, 34097, 42635],
  [14757, 14884, 14980, 15084, 15245, 15426, 15735, 16094, 16724, 17379, 18689, 20295, 23300, 26918, 34108, 42636],
  [14857, 14980, 15085, 15187, 15342, 15526, 15831, 16188, 16820, 17460, 18770, 20370, 23359, 26957, 34125, 42637],
  [14958, 15084, 15187, 15285, 15445, 15625, 15932, 16280, 16907, 17548, 18851, 20446, 23419, 26998, 34139, 42639],
  [15123, 15245, 15342, 15445, 15605, 15784, 16087, 16431, 17045, 17683, 18983, 20567, 23517, 27066, 34164, 42641],
  [15302, 15426, 15526, 15625, 15784, 15961, 16261, 16600, 17183, 17843, 19129, 20703, 23632, 27149, 34193, 42643],
  [15616, 15735, 15831, 15932, 16087, 16261, 16573, 16899, 17414, 18124, 19396, 20952, 23839, 27307, 34258, 42647],
  [15979, 16094, 16188, 16280, 16431, 16600, 16899, 17198, 17732, 18443, 19695, 21231, 24080, 27498, 34345, 42662],
  [16613, 16724, 16820, 16907, 17045, 17183, 17414, 17732, 18313, 19011, 20233, 21736, 24523, 27863, 34544, 42695],
  [17288, 17379, 17460, 17548, 17683, 17843, 18124, 18443, 19011, 19696, 20884, 22352, 25072, 28332, 34841, 42772],
  [18591, 18689, 18770, 18851, 18983, 19129, 19396, 19695, 20233, 20884, 22076, 23485, 26094, 29241, 35499, 43067],
  [20206, 20295, 20370, 20446, 20567, 20703, 20952, 21231, 21736, 22352, 23485, 24840, 27224, 30386, 36330, 43638],
  [23228, 23300, 23359, 23419, 23517, 23632, 23839, 24080, 24523, 25072, 26094, 27224, 29604, 32602, 38145, 45081],
  [26871, 26918, 26957, 26998, 27066, 27149, 27307, 27498, 27863, 28332, 29241, 30386, 32602, 35434, 40696, 47134],
  [34097, 34108, 34125, 34139, 34164, 34193, 34258, 34345, 34544, 34841, 35499, 36330, 38145, 40696, 45450, 51542],
  [42635, 42636, 42637, 42639, 42641, 42643, 42647, 42662, 42695, 42772, 43067, 43638, 45081, 47134, 51542, 56999]
  ],
  [
  [22931, 23015, 23082, 23156, 23272, 23400, 23639, 23925, 24440, 25084, 26237, 27628, 30481, 34097, 40524, 48336],
  [23015, 23101, 23168, 23243, 23354, 23486, 23718, 24004, 24512, 25149, 26297, 27677, 30508, 34108, 40527, 48337],
  [23082, 23168, 23243, 23315, 23425, 23554, 23786, 24070, 24574, 25207, 26344, 27719, 30533, 34125, 40529, 48338],
  [23156, 23243, 23315, 23389, 23493, 23625, 23851, 24134, 24637, 25267, 26391, 27762, 30559, 34139, 40534, 48339],
  [23272, 23354, 23425, 23493, 23608, 23741, 23965, 24240, 24740, 25362, 26463, 27833, 30606, 34164, 40537, 48340],
  [23400, 23486, 23554, 23625, 23741, 23871, 24094, 24361, 24857, 25474, 26571, 27915, 30665, 34193, 40540, 48341],
  [23639, 23718, 23786, 23851, 23965, 24094, 24328, 24587, 25071, 25673, 26692, 28071, 30781, 34258, 40553, 48342],
  [23925, 24004, 24070, 24134, 24240, 24361, 24587, 24845, 25320, 25905, 26891, 28260, 30926, 34345, 40575, 48344],
  [24440, 24512, 24574, 24637, 24740, 24857, 25071, 25320, 25781, 26331, 27289, 28624, 31218, 34544, 40634, 48348],
  [25084, 25149, 25207, 25267, 25362, 25474, 25673, 25905, 26331, 26808, 27805, 29098, 31613, 34841, 40758, 48353],
  [26237, 26297, 26344, 26391, 26463, 26571, 26692, 26891, 27289, 27805, 28804, 30030, 32422, 35499, 41131, 48449],
  [27628, 27677, 27719, 27762, 27833, 27915, 28071, 28260, 28624, 29098, 30030, 31211, 33479, 36330, 41775, 48724],
  [30481, 30508, 30533, 30559, 30606, 30665, 30781, 30926, 31218, 31613, 32422, 33479, 35584, 38145, 43319, 49733],
  [34097, 34108, 34125, 34139, 34164, 34193, 34258, 34345, 34544, 34841, 35499, 36330, 38145, 40696, 45450, 51542],
  [40524, 40527, 40529, 40534, 40537, 40540, 40553, 40575, 40634, 40758, 41131, 41775, 43319, 45450, 49971, 55452],
  [48336, 48337, 48338, 48339, 48340, 48341, 48342, 48344, 48348, 48353, 48449, 48724, 49733, 51542, 55452, 60505]
  ],
  [
  [34469, 34480, 34493, 34509, 34538, 34570, 34646, 34754, 34992, 35355, 36119, 37143, 39499, 42635, 48336, 55377],
  [34480, 34500, 34509, 34526, 34556, 34585, 34662, 34771, 35007, 35366, 36126, 37144, 39500, 42636, 48337, 55377],
  [34493, 34509, 34524, 34541, 34568, 34601, 34675, 34781, 35020, 35381, 36134, 37151, 39501, 42637, 48338, 55378],
  [34509, 34526, 34541, 34561, 34587, 34620, 34692, 34798, 35034, 35392, 36142, 37157, 39503, 42639, 48339, 55378],
  [34538, 34556, 34568, 34587, 34613, 34649, 34720, 34823, 35060, 35414, 36154, 37166, 39513, 42641, 48340, 55379],
  [34570, 34585, 34601, 34620, 34649, 34688, 34758, 34858, 35090, 35441, 36174, 37183, 39517, 42643, 48341, 55379],
  [34646, 34662, 34675, 34692, 34720, 34758, 34836, 34932, 35162, 35504, 36217, 37216, 39535, 42647, 48342, 55380],
  [34754, 34771, 34781, 34798, 34823, 34858, 34932, 35038, 35258, 35591, 36270, 37278, 39567, 42662, 48344, 55381],
  [34992, 35007, 35020, 35034, 35060, 35090, 35162, 35258, 35482, 35795, 36423, 37418, 39649, 42695, 48348, 55382],
  [35355, 35366, 35381, 35392, 35414, 35441, 35504, 35591, 35795, 36099, 36672, 37647, 39810, 42772, 48353, 55383],
  [36119, 36126, 36134, 36142, 36154, 36174, 36217, 36270, 36423, 36672, 37321, 38230, 40256, 43067, 48449, 55385],
  [37143, 37144, 37151, 37157, 37166, 37183, 37216, 37278, 37418, 37647, 38230, 39115, 40993, 43638, 48724, 55407],
  [39499, 39500, 39501, 39503, 39513, 39517, 39535, 39567, 39649, 39810, 40256, 40993, 42710, 45081, 49733, 55763],
  [42635, 42636, 42637, 42639, 42641, 42643, 42647, 42662, 42695, 42772, 43067, 43638, 45081, 47134, 51542, 56999],
  [48336, 48337, 48338, 48339, 48340, 48341, 48342, 48344, 48348, 48353, 48449, 48724, 49733, 51542, 55452, 60505],
  [55377, 55377, 55378, 55378, 55379, 55379, 55380, 55381, 55382, 55383, 55385, 55407, 55763, 56999, 60505, 65119]
  ]
 ];


    
    function processAudio(e)
    {
        fillBuffer(e.outputBuffer.getChannelData(0));
    }

    function AY8912_reset() {
        AY8912_register_latch = 0;
        AY8912_OutputA = 0;
        AY8912_OutputB = 0;
        AY8912_OutputC = 0;
        AY8912_OutputN = 0xFF;
        AY8912_PeriodA = 0;
        AY8912_PeriodB = 0;
        AY8912_PeriodC = 0;
        AY8912_PeriodN = 0;
        AY8912_PeriodE = 0;
        AY8912_CountA = 0;
        AY8912_CountB = 0;
        AY8912_CountC = 0;
        AY8912_CountN = 0;
        AY8912_CountE = 0;
        AY8912_VolA = 0;
        AY8912_VolB = 0;
        AY8912_VolC = 0;
        AY8912_VolE = 0;
        AY8912_EnvelopeA = 0;
        AY8912_EnvelopeB = 0;
        AY8912_EnvelopeC = 0;
        AY8912_CountEnv = 0;
        AY8912_Hold = 0;
        AY8912_Alternate = 0;
        AY8912_Holding = 0;
        AY8912_Attack = 0;

        for (var i = 0; i <= AY_PORTB; i++) {
            AYWriteReg(i, 0);     //* AYWriteReg() uses the timer system; we cannot
        }                    //* call it at this time because the timer system
        //* has not been initialized.
    }

    function AY8912_set_clock(clock) {
        // the AY_STEP clock for the tone and noise generators is the chip clock    
        //divided by 8; for the envelope generator of the AY-3-8912, it is half 
        // that much (clock/16), but the envelope of the YM2149 goes twice as    
        // fast, therefore again clock/8.                                        
        // Here we calculate the number of AY_STEPs which happen during one sample  
        // at the given sample rate. No. of events = sample rate / (clock/8).    */
        // AY_STEP is a multiplier used to turn the fraction into a fixed point     */
        // number.}
        var t1 = AY_STEP * AY8912_sampleRate * 8.0;
        AY8912_UpdateStep = t1 / clock;
    }

    //
    // ** set output gain
    // **
    // ** The gain is expressed in 0.2dB increments, e.g. a gain of 10 is an increase
    // ** of 2dB. Note that the gain only affects sounds not playing at full volume,
    // ** since the ones at full volume are already played at the maximum intensity
    // ** allowed by the sound card.
    // ** 0x00 is the default.
    // ** 0xff is the maximum allowed value.
    // 

    function AYWriteReg(r, v) {
        var old;

        AY8912_Regs[r] = v;

        //on ST drive select is mapped to PSG register 14
        if (r == AY_PORTA) fdc.selectDrive((~v) & 7);

        //'/* A note about the period of tones, noise and envelope: for speed reasons,*/
        //'/* we count down from the period to 0, but careful studies of the chip     */
        //'/* output prove that it instead counts up from 0 until the counter becomes */
        //'/* greater or equal to the period. This is an important difference when the*/
        //'/* program is rapidly changing the period to modulate the sound.           */
        //'/* To compensate for the difference, when the period is changed we adjust  */
        //'/* our internal counter.                                                   */
        //'/* Also, note that period = 0 is the same as period = 1. This is mentioned */
        //'/* in the YM2203 data sheets. However, this does NOT apply to the Envelope */
        //'/* period. In that case, period = 0 is half as period = 1. 
        switch (r) {
            case AY_AFINE:
            case AY_ACOARSE:

                //AY8912_Regs[AY_ACOARSE] = AY8912_Regs[AY_ACOARSE] & 0xF;

                old = AY8912_PeriodA;

                AY8912_PeriodA = Math.round((AY8912_Regs[AY_AFINE] + (256 * (AY8912_Regs[AY_ACOARSE] & 0xf)))
            * AY8912_UpdateStep);

                if (AY8912_PeriodA == 0)
                    AY8912_PeriodA = Math.round(AY8912_UpdateStep);

                AY8912_CountA = AY8912_CountA + (AY8912_PeriodA - old);

                if (AY8912_CountA <= 0)
                    AY8912_CountA = 1;
                break;
            case AY_BFINE:
            case AY_BCOARSE:

                //AY8912_Regs[AY_BCOARSE] = AY8912_Regs[AY_BCOARSE] & 0xF;

                old = AY8912_PeriodB;

                AY8912_PeriodB = Math.round((AY8912_Regs[AY_BFINE] + (256 * (AY8912_Regs[AY_BCOARSE] & 0xf)))
            * AY8912_UpdateStep);

                if (AY8912_PeriodB == 0)
                    AY8912_PeriodB = Math.round(AY8912_UpdateStep);

                AY8912_CountB = AY8912_CountB + AY8912_PeriodB - old;

                if (AY8912_CountB <= 0)
                    AY8912_CountB = 1;
                break;

            case AY_CFINE:
            case AY_CCOARSE:

                //AY8912_Regs[AY_CCOARSE] = AY8912_Regs[AY_CCOARSE] & 0xF;

                old = AY8912_PeriodC;

                AY8912_PeriodC = Math.round((AY8912_Regs[AY_CFINE] + (256 * (AY8912_Regs[AY_CCOARSE] & 0xf)))
            * AY8912_UpdateStep);

                if (AY8912_PeriodC == 0)
                    AY8912_PeriodC = Math.round(AY8912_UpdateStep);

                AY8912_CountC = AY8912_CountC + (AY8912_PeriodC - old);

                if (AY8912_CountC <= 0)
                    AY8912_CountC = 1;
                break;

            case AY_NOISEPER:

                AY8912_Regs[AY_NOISEPER] = AY8912_Regs[AY_NOISEPER] & 0x1F;

                old = AY8912_PeriodN;

                AY8912_PeriodN = Math.round(AY8912_Regs[AY_NOISEPER] * AY8912_UpdateStep);

                if (AY8912_PeriodN == 0)
                    AY8912_PeriodN = Math.round(AY8912_UpdateStep);

                AY8912_CountN = AY8912_CountN + (AY8912_PeriodN - old);

                if (AY8912_CountN <= 0)
                    AY8912_CountN = 1;
                break;

            case AY_AVOL:

                AY8912_Regs[AY_AVOL] = AY8912_Regs[AY_AVOL] & 0x1F;

                AY8912_EnvelopeA = AY8912_Regs[AY_AVOL] & 0x10;

                if (AY8912_EnvelopeA != 0)
                    AY8912_VolA = AY8912_VolE
                else {
                    AY8912_VolA = AY8912_Regs[AY_AVOL]
                }
                break;

            case AY_BVOL:

                AY8912_Regs[AY_BVOL] = AY8912_Regs[AY_BVOL] & 0x1F;

                AY8912_EnvelopeB = AY8912_Regs[AY_BVOL] & 0x10;

                if (AY8912_EnvelopeB != 0)
                    AY8912_VolB = AY8912_VolE
                else {
                    AY8912_VolB = AY8912_Regs[AY_BVOL];
                };
                break;

            case AY_CVOL:

                AY8912_Regs[AY_CVOL] = AY8912_Regs[AY_CVOL] & 0x1F;

                AY8912_EnvelopeC = AY8912_Regs[AY_CVOL] & 0x10;

                if (AY8912_EnvelopeC != 0)
                    AY8912_VolC = AY8912_VolE
                else {
                    AY8912_VolC = AY8912_Regs[AY_CVOL];

                };
                break;

            case AY_EFINE:
            case AY_ECOARSE:

                old = AY8912_PeriodE;

                AY8912_PeriodE = Math.round(((AY8912_Regs[AY_EFINE] + (256 * AY8912_Regs[AY_ECOARSE])))
            * AY8912_UpdateStep);

                if (AY8912_PeriodE == 0)
                    AY8912_PeriodE = Math.round(AY8912_UpdateStep / 2);

                AY8912_CountE = AY8912_CountE + (AY8912_PeriodE - old);

                if (AY8912_CountE <= 0)
                    AY8912_CountE = 1
                break;

            case AY_ESHAPE:

                //' envelope shapes:
                //'C AtAlH
                //'0 0 x x  \___
                //'
                //'0 1 x x  /___
                //'
                //'1 0 0 0  \\\\
                //'
                //'1 0 0 1  \___
                //'
                //'1 0 1 0  \/\/
                //'          ___
                //'1 0 1 1  \
                //'
                //'1 1 0 0  ////
                //'          ___
                //'1 1 0 1  /
                //'
                //'1 1 1 0  /\/\
                //'
                //'1 1 1 1  /___
                //'
                //'The envelope counter on the AY-3-8910 has 16 AY_STEPs. On the YM2149 it
                //'has twice the AY_STEPs, happening twice as fast. Since the end result is
                //'just a smoother curve, we always use the YM2149 behaviour.
                //'}
                if (AY8912_Regs[AY_ESHAPE] != 0xFF) {
                    AY8912_Regs[AY_ESHAPE] = AY8912_Regs[AY_ESHAPE] & 0xF;

                    if ((AY8912_Regs[AY_ESHAPE] & 0x4) == 0x4)
                        AY8912_Attack = MAXVOL
                    else
                        AY8912_Attack = 0x0;

                    AY8912_Hold = AY8912_Regs[AY_ESHAPE] & 0x1;

                    AY8912_Alternate = AY8912_Regs[AY_ESHAPE] & 0x2;

                    AY8912_CountE = AY8912_PeriodE;

                    AY8912_CountEnv = MAXVOL; // &h1f

                    AY8912_Holding = 0;

                    //AY8912_VolE = AY8912_VolTable2[AY8912_CountEnv ^ AY8912_Attack];
                    AY8912_VolE = (AY8912_CountEnv ^ AY8912_Attack) >> 1;

                    if (AY8912_EnvelopeA != 0)
                        AY8912_VolA = AY8912_VolE;

                    if (AY8912_EnvelopeB != 0)
                        AY8912_VolB = AY8912_VolE;

                    if (AY8912_EnvelopeC != 0)
                        AY8912_VolC = AY8912_VolE;
                }
                break;
        }
    }

    function AYReadReg(r) {
        return AY8912_Regs[r];
    }


    function AY8912_init(clock, sample_rate, sample_bits) {
        AY8912_sampleRate = sample_rate;
        AY8912_set_clock(clock);
        AY8912_reset();
        return 0;
    }

    function AY8912Update_8() {
        var Buffer_Length = 400;

        //  The 8910 has three outputs, each output is the mix of one of the three 
        //  tone generators and of the (single) noise generator. The two are mixed 
        //  BEFORE going into the DAC. The formula to mix each channel is: 
        //  (ToneOn | ToneDisable) & (NoiseOn | NoiseDisable). 
        //  Note that this means that if both tone and noise are disabled, the output 
        //  is 1, not 0, and can be modulated changing the volume. 
        //  if the channels are disabled, set their output to 1, and increase the 
        //  counter, if necessary, so they will not be inverted during this update. 
        //  Setting the output to 1 is necessary because a disabled channel is locked 
        //  into the ON state (see above); and it has no effect if the volume is 0. 
        //  if the volume is 0, increase the counter, but don't touch the output. 

        if ((AY8912_Regs[AY_ENABLE] & 0x1) == 0x1) {

            if (AY8912_CountA <= (Buffer_Length * AY_STEP))
                AY8912_CountA = AY8912_CountA + (Buffer_Length * AY_STEP);

            AY8912_OutputA = 1;
        }
        else if (AY8912_Regs[AY_AVOL] == 0) {

            // note that I do count += Buffer_Length, NOT count = Buffer_Length + 1. You might think
            // it's the same since the volume is 0, but doing the latter could cause
            // interferencies when the program is rapidly modulating the volume.
            if (AY8912_CountA <= (Buffer_Length * AY_STEP))
                AY8912_CountA = AY8912_CountA + (Buffer_Length * AY_STEP);
        }

        if ((AY8912_Regs[AY_ENABLE] & 0x2) == 0x2) {

            if (AY8912_CountB <= (Buffer_Length * AY_STEP))
                AY8912_CountB = AY8912_CountB + (Buffer_Length * AY_STEP);

            AY8912_OutputB = 1;
        }
        else if (AY8912_Regs[AY_BVOL] == 0) {
            if (AY8912_CountB <= (Buffer_Length * AY_STEP))
                AY8912_CountB = AY8912_CountB + (Buffer_Length * AY_STEP);
        }

        if ((AY8912_Regs[AY_ENABLE] & 0x4) == 0x4) {
            if (AY8912_CountC <= (Buffer_Length * AY_STEP))
                AY8912_CountC = AY8912_CountC + (Buffer_Length * AY_STEP);

            AY8912_OutputC = 1;
        }
        else if ((AY8912_Regs[AY_CVOL] == 0)) {
            if (AY8912_CountC <= (Buffer_Length * AY_STEP))
                AY8912_CountC = AY8912_CountC + (Buffer_Length * AY_STEP);
        }

        // for the noise channel we must not touch OutputN - it's also not necessary 
        // since we use AY_OutNoise. 
        if ((AY8912_Regs[AY_ENABLE] & 0x38) == 0x38) { // all off 
            if (AY8912_CountN <= (Buffer_Length * AY_STEP))
                AY8912_CountN = AY8912_CountN + (Buffer_Length * AY_STEP);
        }

        AY_OutNoise = (AY8912_OutputN | AY8912_Regs[AY_ENABLE]);
    }

    function RenderSample() {
        var VolA, VolB, VolC, AY_Left, lOut1, lOut2, lOut3, AY_NextEvent;

        VolA = 0; VolB = 0; VolC = 0;

        //vola, volb and volc keep track of how long each square wave stays
        //in the 1 position during the sample period.

        AY_Left = AY_STEP;

        do {
            AY_NextEvent = 0;

            if (AY8912_CountN < AY_Left)
                AY_NextEvent = AY8912_CountN
            else
                AY_NextEvent = AY_Left;

            if ((AY_OutNoise & 0x8) == 0x8) {
                if (AY8912_OutputA == 1) VolA = VolA + AY8912_CountA;

                AY8912_CountA = AY8912_CountA - AY_NextEvent;

                //PeriodA is the half period of the square wave. Here, in each
                // loop I add PeriodA twice, so that at the end of the loop the
                // square wave is in the same status (0 or 1) it was at the start.
                // vola is also incremented by PeriodA, since the wave has been 1
                // exactly half of the time, regardless of the initial position.
                // If we exit the loop in the middle, OutputA has to be inverted
                // and vola incremented only if the exit status of the square
                // wave is 1.

                while (AY8912_CountA <= 0) {
                    AY8912_CountA = AY8912_CountA + AY8912_PeriodA;
                    if (AY8912_CountA > 0) {
                        if ((AY8912_Regs[AY_ENABLE] & 1) == 0) AY8912_OutputA = AY8912_OutputA ^ 1;
                        if (AY8912_OutputA != 0) VolA = VolA + AY8912_PeriodA;
                        break;
                    }

                    AY8912_CountA = AY8912_CountA + AY8912_PeriodA;
                    VolA = VolA + AY8912_PeriodA;
                }
                if (AY8912_OutputA == 1) VolA = VolA - AY8912_CountA;
            }
            else {
                AY8912_CountA = AY8912_CountA - AY_NextEvent;

                while (AY8912_CountA <= 0) {
                    AY8912_CountA = AY8912_CountA + AY8912_PeriodA;
                    if (AY8912_CountA > 0) {
                        AY8912_OutputA = AY8912_OutputA ^ 1;
                        break;
                    }
                    AY8912_CountA = AY8912_CountA + AY8912_PeriodA;
                }
            }

            if ((AY_OutNoise & 0x10) == 0x10) {
                if (AY8912_OutputB == 1) VolB = VolB + AY8912_CountB;
                AY8912_CountB = AY8912_CountB - AY_NextEvent;

                while (AY8912_CountB <= 0) {
                    AY8912_CountB = AY8912_CountB + AY8912_PeriodB;
                    if (AY8912_CountB > 0) {
                        if ((AY8912_Regs[AY_ENABLE] & 2) == 0) AY8912_OutputB = AY8912_OutputB ^ 1;
                        if (AY8912_OutputB != 0) VolB = VolB + AY8912_PeriodB;
                        break;
                    }
                    AY8912_CountB = AY8912_CountB + AY8912_PeriodB;
                    VolB = VolB + AY8912_PeriodB;
                }
                if (AY8912_OutputB == 1) VolB = VolB - AY8912_CountB;
            }
            else {
                AY8912_CountB = AY8912_CountB - AY_NextEvent;

                while (AY8912_CountB <= 0) {
                    AY8912_CountB = AY8912_CountB + AY8912_PeriodB;
                    if (AY8912_CountB > 0) {
                        AY8912_OutputB = AY8912_OutputB ^ 1;
                        break;
                    }
                    AY8912_CountB = AY8912_CountB + AY8912_PeriodB;
                }
            }

            if ((AY_OutNoise & 0x20) == 0x20) {
                if (AY8912_OutputC == 1) VolC = VolC + AY8912_CountC;
                AY8912_CountC = AY8912_CountC - AY_NextEvent;
                while (AY8912_CountC <= 0) {
                    AY8912_CountC = AY8912_CountC + AY8912_PeriodC;
                    if (AY8912_CountC > 0) {
                        if ((AY8912_Regs[AY_ENABLE] & 4) == 0) AY8912_OutputC = AY8912_OutputC ^ 1;
                        if (AY8912_OutputC != 0) VolC = VolC + AY8912_PeriodC;
                        break;
                    }

                    AY8912_CountC = AY8912_CountC + AY8912_PeriodC;
                    VolC = VolC + AY8912_PeriodC;
                }
                if (AY8912_OutputC == 1) VolC = VolC - AY8912_CountC;
            }
            else {

                AY8912_CountC = AY8912_CountC - AY_NextEvent;
                while (AY8912_CountC <= 0) {
                    AY8912_CountC = AY8912_CountC + AY8912_PeriodC;
                    if (AY8912_CountC > 0) {
                        AY8912_OutputC = AY8912_OutputC ^ 1;
                        break;
                    }
                    AY8912_CountC = AY8912_CountC + AY8912_PeriodC;
                }
            }

            AY8912_CountN = AY8912_CountN - AY_NextEvent;
            if (AY8912_CountN <= 0) {
                //Is noise output going to change?
                AY8912_OutputN = Math.round(Math.random() * 511);
                AY_OutNoise = (AY8912_OutputN | AY8912_Regs[AY_ENABLE]);
                AY8912_CountN = AY8912_CountN + AY8912_PeriodN;
            }

            AY_Left = AY_Left - AY_NextEvent;
        } while (AY_Left > 0);


        if (AY8912_Holding == 0) {
            AY8912_CountE = AY8912_CountE - AY_STEP;
            if (AY8912_CountE <= 0) {
                do {
                    AY8912_CountEnv = AY8912_CountEnv - 1;
                    AY8912_CountE = AY8912_CountE + AY8912_PeriodE;
                }
                while (AY8912_CountE <= 0);

                //check envelope current position
                if (AY8912_CountEnv < 0) {
                    if (AY8912_Hold != 0) {
                        if (AY8912_Alternate != 0) {
                            AY8912_Attack = AY8912_Attack ^ MAXVOL; //0x1f
                        }
                        AY8912_Holding = 1;
                        AY8912_CountEnv = 0;
                    }
                    else {
                        //if CountEnv has looped an odd number of times (usually 1),
                        //invert the output.
                        if ((AY8912_Alternate != 0) & ((AY8912_CountEnv & 0x20) == 0x20)) {
                            AY8912_Attack = AY8912_Attack ^ MAXVOL; //0x1f
                        }

                        AY8912_CountEnv = AY8912_CountEnv & MAXVOL;  //0x1f
                    }

                }

                //AY8912_VolE = AY8912_VolTable2[AY8912_CountEnv ^ AY8912_Attack];
                AY8912_VolE = (AY8912_CountEnv ^ AY8912_Attack) >> 1;

                //reload volume
                if (AY8912_EnvelopeA != 0) AY8912_VolA = AY8912_VolE;
                if (AY8912_EnvelopeB != 0) AY8912_VolB = AY8912_VolE;
                if (AY8912_EnvelopeC != 0) AY8912_VolC = AY8912_VolE;

            }


        } else {
            //reload volume
            if (AY8912_EnvelopeA != 0) AY8912_VolA = 0;
            if (AY8912_EnvelopeB != 0) AY8912_VolB = 0;
            if (AY8912_EnvelopeC != 0) AY8912_VolC = 0;
        }

        if (AY8912_PeriodA <= AY8912_UpdateStep) {
            VolA = 16384;
        }

        if (AY8912_PeriodB <= AY8912_UpdateStep) {
            VolB = 16384;
        }

        if (AY8912_PeriodC <= AY8912_UpdateStep) {
            VolC = 16384;
        }

        lOut1 = Math.min(15, (VolA * AY8912_VolA) >> 14);
        lOut2 = Math.min(15, (VolB * AY8912_VolB) >> 14);
        lOut3 = Math.min(15, (VolC * AY8912_VolC) >> 14);

        return volTable[lOut3][lOut2][lOut1] / 65536;


    }

    function fillBuffer(outputArray) {
        try {
            bug.say("audio fillBuffer");
            var n = outputArray.length;
            var n2 = audioBuffer.length;
            if (!soundEnabled) {
                n2 = 0;
            }

            resampleBuffer(n);

            for (var i = 0; i < n; i++) {
                outputArray[i] = audioBuffer[i];
            }

            audioBuffer.splice(0, n);
        }
        catch (e)
        {
            bug.say("audio fillBuffer error "+e.message);
        }

    }

    function resampleBuffer(count) {
        var newBuffer = new Array();
        for (var i = 0; i < count; i++) {
            newBuffer.push(audioBuffer[~ ~(i / count * audioBuffer.length)]);
        }
        audioBuffer = newBuffer;
    }

    function writeSampleData(soundIsEnabled) {
        soundEnabled = soundIsEnabled;
        if (audioBuffer != null) {
            if (!soundEnabled) {
                audioBuffer.length = 0;
                lastWritten = currTime;
                return;
            }

            if (audioOutput != null) {

                var currTime = new Date();
                samplesNeeded = ~ ~(sampleRate / (1000 / (currTime - lastWritten)));

                if (audioBuffer.length < samplesNeeded) resampleBuffer(samplesNeeded);


                lastWritten = currTime;

                numberSamplesWritten = audioOutput.mozWriteAudio(audioBuffer);
                //audioBuffer2.splice(0, numberSamplesWritten);
                audioBuffer.length = 0;
            }
        }


    }

    function handleAySound(size) {
        if (audioBuffer != null) {
            size = ~ ~(size);
            while (size-- > 0) {
                WCount++;
                if (WCount == 25) {
                    AY8912Update_8();
                    WCount = 0;
                }
                audioBuffer.push(RenderSample());
                soundDataFrameBytes++;
            }
        }
    }


    self.startFrame = function () {
        rowCount = 0;
        soundDataFrameBytes = 0;
        frameCount++;
    }

    self.endFrame = function (enabled) {

        handleAySound(sampleRate / 50 - soundDataFrameBytes);
        soundDataFrameBytes = 0;
        if (frameCount++ < 2) return;

        writeSampleData(enabled);
    }

    self.processRow = function () {
        rowCount++
        handleAySound((Math.round(rowCount * sampleRate / 50 / 313)) - soundDataFrameBytes);
    }


    self.reset = function () {
        AY_OutNoise = 0;
        AY8912_init(clock, sampleRate, 8);
    }

    self.selectRegister = function (reg) {
        regSelect = reg;
    }

    self.readRegister = function () {
        if (regSelect < 16) {
            return AY8912_Regs[regSelect];
        }
        else {
            return 0xff;
        }
    }

    self.writeRegister = function (val) {
        var cycle = processor.getRowCycleCount()
        var sound_size = Math.round((rowCount * 512 + cycle) * sampleRate / 50 / 313 / 512) - soundDataFrameBytes
        handleAySound(sound_size);

        if (regSelect < 16) AYWriteReg(regSelect, val);
    }

    self.setProcessor = function (p) {
        processor = p;
    }

    self.init = function () {
        var AudioContext = window.AudioContext || window.webkitAudioContext;
        if (AudioContext) {
            /* Use Web Audio API */
            audioBuffer = new Array();

            audioContext = new AudioContext();
            if (audioContext.createJavaScriptNode != null) {
                audioNode = audioContext.createJavaScriptNode(16384, 1, 1);
            } else if (audioContext.createScriptProcessor != null) {
                audioNode = audioContext.createScriptProcessor(16384, 1, 1);
            } else {
                audioNode = null;
            }

            if (audioNode != null) {
                audioNode.onaudioprocess = processAudio;

                audioNode.connect(audioContext.destination);
            }
        }
        else if (typeof (Audio) != 'undefined') {
            /* Use audio data api */
            audioOutput = new Audio();
            if (typeof (audioOutput.mozSetup) != 'undefined') {
                audioBuffer = new Array();
                audioBuffer2 = new Array();
                audioOutput.mozSetup(1, samplesPerFrame * 50);
            } else {
                audioOutput = null;
            }
        }

    }

    return self;
}