dosbox-wii/src/hardware/tandy_sound.cpp

587 lines
14 KiB
C++

/*
* Copyright (C) 2002-2011 The DOSBox Team
*
* 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 the
* 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.
*/
/*
Based of sn76496.c of the M.A.M.E. project
*/
#include "dosbox.h"
#include "inout.h"
#include "mixer.h"
#include "mem.h"
#include "setup.h"
#include "pic.h"
#include "dma.h"
#include "hardware.h"
#include <cstring>
#include <math.h>
#define MAX_OUTPUT 0x7fff
#define STEP 0x10000
/* Formulas for noise generator */
/* bit0 = output */
/* noise feedback for white noise mode (verified on real SN76489 by John Kortink) */
#define FB_WNOISE 0x14002 /* (16bits) bit16 = bit0(out) ^ bit2 ^ bit15 */
/* noise feedback for periodic noise mode */
//#define FB_PNOISE 0x10000 /* 16bit rorate */
#define FB_PNOISE 0x08000 /* JH 981127 - fixes Do Run Run */
/*
0x08000 is definitely wrong. The Master System conversion of Marble Madness
uses periodic noise as a baseline. With a 15-bit rotate, the bassline is
out of tune.
The 16-bit rotate has been confirmed against a real PAL Sega Master System 2.
Hope that helps the System E stuff, more news on the PSG as and when!
*/
/* noise generator start preset (for periodic noise) */
#define NG_PRESET 0x0f35
struct SN76496 {
int SampleRate;
unsigned int UpdateStep;
int VolTable[16]; /* volume table */
int Register[8]; /* registers */
int LastRegister; /* last register written */
int Volume[4]; /* volume of voice 0-2 and noise */
unsigned int RNG; /* noise generator */
int NoiseFB; /* noise feedback mask */
int Period[4];
int Count[4];
int Output[4];
};
static struct SN76496 sn;
#define TDAC_DMA_BUFSIZE 1024
static struct {
MixerChannel * chan;
bool enabled;
Bitu last_write;
struct {
MixerChannel * chan;
bool enabled;
struct {
Bitu base;
Bit8u irq,dma;
} hw;
struct {
Bitu rate;
Bit8u buf[TDAC_DMA_BUFSIZE];
Bit8u last_sample;
DmaChannel * chan;
bool transfer_done;
} dma;
Bit8u mode,control;
Bit16u frequency;
Bit8u amplitude;
bool irq_activated;
} dac;
} tandy;
static void SN76496Write(Bitu /*port*/,Bitu data,Bitu /*iolen*/) {
struct SN76496 *R = &sn;
tandy.last_write=PIC_Ticks;
if (!tandy.enabled) {
tandy.chan->Enable(true);
tandy.enabled=true;
}
/* update the output buffer before changing the registers */
if (data & 0x80)
{
int r = (data & 0x70) >> 4;
int c = r/2;
R->LastRegister = r;
R->Register[r] = (R->Register[r] & 0x3f0) | (data & 0x0f);
switch (r)
{
case 0: /* tone 0 : frequency */
case 2: /* tone 1 : frequency */
case 4: /* tone 2 : frequency */
R->Period[c] = R->UpdateStep * R->Register[r];
if (R->Period[c] == 0) R->Period[c] = 0x3fe;
if (r == 4)
{
/* update noise shift frequency */
if ((R->Register[6] & 0x03) == 0x03)
R->Period[3] = 2 * R->Period[2];
}
break;
case 1: /* tone 0 : volume */
case 3: /* tone 1 : volume */
case 5: /* tone 2 : volume */
case 7: /* noise : volume */
R->Volume[c] = R->VolTable[data & 0x0f];
break;
case 6: /* noise : frequency, mode */
{
int n = R->Register[6];
R->NoiseFB = (n & 4) ? FB_WNOISE : FB_PNOISE;
n &= 3;
/* N/512,N/1024,N/2048,Tone #3 output */
R->Period[3] = (n == 3) ? 2 * R->Period[2] : (R->UpdateStep << (5+n));
/* reset noise shifter */
// R->RNG = NG_PRESET;
// R->Output[3] = R->RNG & 1;
}
break;
}
}
else
{
int r = R->LastRegister;
int c = r/2;
switch (r)
{
case 0: /* tone 0 : frequency */
case 2: /* tone 1 : frequency */
case 4: /* tone 2 : frequency */
R->Register[r] = (R->Register[r] & 0x0f) | ((data & 0x3f) << 4);
R->Period[c] = R->UpdateStep * R->Register[r];
if (R->Period[c] == 0) R->Period[c] = 0x3fe;
if (r == 4)
{
/* update noise shift frequency */
if ((R->Register[6] & 0x03) == 0x03)
R->Period[3] = 2 * R->Period[2];
}
break;
}
}
}
static void SN76496Update(Bitu length) {
if ((tandy.last_write+5000)<PIC_Ticks) {
tandy.enabled=false;
tandy.chan->Enable(false);
}
int i;
struct SN76496 *R = &sn;
Bit16s * buffer=(Bit16s *)MixTemp;
/* If the volume is 0, increase the counter */
for (i = 0;i < 4;i++)
{
if (R->Volume[i] == 0)
{
/* note that I do count += length, NOT count = 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 (R->Count[i] <= (int)length*STEP) R->Count[i] += length*STEP;
}
}
Bitu count=length;
while (count)
{
int vol[4];
unsigned int out;
int left;
/* vol[] keeps track of how long each square wave stays */
/* in the 1 position during the sample period. */
vol[0] = vol[1] = vol[2] = vol[3] = 0;
for (i = 0;i < 3;i++)
{
if (R->Output[i]) vol[i] += R->Count[i];
R->Count[i] -= STEP;
/* Period[i] is the half period of the square wave. Here, in each */
/* loop I add Period[i] 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. */
/* vol[i] is also incremented by Period[i], since the wave has been 1 */
/* exactly half of the time, regardless of the initial position. */
/* If we exit the loop in the middle, Output[i] has to be inverted */
/* and vol[i] incremented only if the exit status of the square */
/* wave is 1. */
while (R->Count[i] <= 0)
{
R->Count[i] += R->Period[i];
if (R->Count[i] > 0)
{
R->Output[i] ^= 1;
if (R->Output[i]) vol[i] += R->Period[i];
break;
}
R->Count[i] += R->Period[i];
vol[i] += R->Period[i];
}
if (R->Output[i]) vol[i] -= R->Count[i];
}
left = STEP;
do
{
int nextevent;
if (R->Count[3] < left) nextevent = R->Count[3];
else nextevent = left;
if (R->Output[3]) vol[3] += R->Count[3];
R->Count[3] -= nextevent;
if (R->Count[3] <= 0)
{
if (R->RNG & 1) R->RNG ^= R->NoiseFB;
R->RNG >>= 1;
R->Output[3] = R->RNG & 1;
R->Count[3] += R->Period[3];
if (R->Output[3]) vol[3] += R->Period[3];
}
if (R->Output[3]) vol[3] -= R->Count[3];
left -= nextevent;
} while (left > 0);
out = vol[0] * R->Volume[0] + vol[1] * R->Volume[1] +
vol[2] * R->Volume[2] + vol[3] * R->Volume[3];
if (out > MAX_OUTPUT * STEP) out = MAX_OUTPUT * STEP;
*(buffer++) = (Bit16s)(out / STEP);
count--;
}
tandy.chan->AddSamples_m16(length,(Bit16s *)MixTemp);
}
static void SN76496_set_clock(int clock) {
struct SN76496 *R = &sn;
/* the base clock for the tone generators is the chip clock divided by 16; */
/* for the noise generator, it is clock / 256. */
/* Here we calculate the number of steps which happen during one sample */
/* at the given sample rate. No. of events = sample rate / (clock/16). */
/* STEP is a multiplier used to turn the fraction into a fixed point */
/* number. */
R->UpdateStep = (unsigned int)(((double)STEP * R->SampleRate * 16) / clock);
}
static void SN76496_set_gain(int gain) {
struct SN76496 *R = &sn;
int i;
double out;
gain &= 0xff;
/* increase max output basing on gain (0.2 dB per step) */
out = MAX_OUTPUT / 3;
while (gain-- > 0)
out *= 1.023292992; /* = (10 ^ (0.2/20)) */
/* build volume table (2dB per step) */
for (i = 0;i < 15;i++)
{
/* limit volume to avoid clipping */
if (out > MAX_OUTPUT / 3) R->VolTable[i] = MAX_OUTPUT / 3;
else R->VolTable[i] = (int)out;
out /= 1.258925412; /* = 10 ^ (2/20) = 2dB */
}
R->VolTable[15] = 0;
}
bool TS_Get_Address(Bitu& tsaddr, Bitu& tsirq, Bitu& tsdma) {
tsaddr=0;
tsirq =0;
tsdma =0;
if (tandy.dac.enabled) {
tsaddr=tandy.dac.hw.base;
tsirq =tandy.dac.hw.irq;
tsdma =tandy.dac.hw.dma;
return true;
}
return false;
}
static void TandyDAC_DMA_CallBack(DmaChannel * /*chan*/, DMAEvent event) {
if (event == DMA_REACHED_TC) {
tandy.dac.dma.transfer_done=true;
PIC_ActivateIRQ(tandy.dac.hw.irq);
}
}
static void TandyDACModeChanged(void) {
switch (tandy.dac.mode&3) {
case 0:
// joystick mode
break;
case 1:
break;
case 2:
// recording
break;
case 3:
// playback
tandy.dac.chan->FillUp();
if (tandy.dac.frequency!=0) {
float freq=3579545.0f/((float)tandy.dac.frequency);
tandy.dac.chan->SetFreq((Bitu)freq);
float vol=((float)tandy.dac.amplitude)/7.0f;
tandy.dac.chan->SetVolume(vol,vol);
if ((tandy.dac.mode&0x0c)==0x0c) {
tandy.dac.dma.transfer_done=false;
tandy.dac.dma.chan=GetDMAChannel(tandy.dac.hw.dma);
if (tandy.dac.dma.chan) {
tandy.dac.dma.chan->Register_Callback(TandyDAC_DMA_CallBack);
tandy.dac.chan->Enable(true);
// LOG_MSG("Tandy DAC: playback started with freqency %f, volume %f",freq,vol);
}
}
}
break;
}
}
static void TandyDACDMAEnabled(void) {
TandyDACModeChanged();
}
static void TandyDACDMADisabled(void) {
}
static void TandyDACWrite(Bitu port,Bitu data,Bitu /*iolen*/) {
switch (port) {
case 0xc4: {
Bitu oldmode = tandy.dac.mode;
tandy.dac.mode = (Bit8u)(data&0xff);
if ((data&3)!=(oldmode&3)) {
TandyDACModeChanged();
}
if (((data&0x0c)==0x0c) && ((oldmode&0x0c)!=0x0c)) {
TandyDACDMAEnabled();
} else if (((data&0x0c)!=0x0c) && ((oldmode&0x0c)==0x0c)) {
TandyDACDMADisabled();
}
}
break;
case 0xc5:
switch (tandy.dac.mode&3) {
case 0:
// joystick mode
break;
case 1:
tandy.dac.control = (Bit8u)(data&0xff);
break;
case 2:
break;
case 3:
// direct output
break;
}
break;
case 0xc6:
tandy.dac.frequency = tandy.dac.frequency & 0xf00 | (Bit8u)(data&0xff);
switch (tandy.dac.mode&3) {
case 0:
// joystick mode
break;
case 1:
case 2:
case 3:
TandyDACModeChanged();
break;
}
break;
case 0xc7:
tandy.dac.frequency = tandy.dac.frequency & 0x00ff | (((Bit8u)(data&0xf))<<8);
tandy.dac.amplitude = (Bit8u)(data>>5);
switch (tandy.dac.mode&3) {
case 0:
// joystick mode
break;
case 1:
case 2:
case 3:
TandyDACModeChanged();
break;
}
break;
}
}
static Bitu TandyDACRead(Bitu port,Bitu /*iolen*/) {
switch (port) {
case 0xc4:
return (tandy.dac.mode&0x77) | (tandy.dac.irq_activated ? 0x08 : 0x00);
case 0xc6:
return (Bit8u)(tandy.dac.frequency&0xff);
case 0xc7:
return (Bit8u)(((tandy.dac.frequency>>8)&0xf) | (tandy.dac.amplitude<<5));
}
LOG_MSG("Tandy DAC: Read from unknown %X",port);
return 0xff;
}
static void TandyDACGenerateDMASound(Bitu length) {
if (length) {
Bitu read=tandy.dac.dma.chan->Read(length,tandy.dac.dma.buf);
tandy.dac.chan->AddSamples_m8(read,tandy.dac.dma.buf);
if (read < length) {
if (read>0) tandy.dac.dma.last_sample=tandy.dac.dma.buf[read-1];
for (Bitu ct=read; ct < length; ct++) {
tandy.dac.chan->AddSamples_m8(1,&tandy.dac.dma.last_sample);
}
}
}
}
static void TandyDACUpdate(Bitu length) {
if (tandy.dac.enabled && ((tandy.dac.mode&0x0c)==0x0c)) {
if (!tandy.dac.dma.transfer_done) {
Bitu len = length;
TandyDACGenerateDMASound(len);
} else {
for (Bitu ct=0; ct < length; ct++) {
tandy.dac.chan->AddSamples_m8(1,&tandy.dac.dma.last_sample);
}
}
} else {
tandy.dac.chan->AddSilence();
}
}
class TANDYSOUND: public Module_base {
private:
IO_WriteHandleObject WriteHandler[4];
IO_ReadHandleObject ReadHandler[4];
MixerObject MixerChan;
MixerObject MixerChanDAC;
public:
TANDYSOUND(Section* configuration):Module_base(configuration){
Section_prop * section=static_cast<Section_prop *>(configuration);
bool enable_hw_tandy_dac=true;
Bitu sbport, sbirq, sbdma;
if (SB_Get_Address(sbport, sbirq, sbdma)) {
enable_hw_tandy_dac=false;
}
real_writeb(0x40,0xd4,0x00);
if (IS_TANDY_ARCH) {
/* enable tandy sound if tandy=true/auto */
if ((strcmp(section->Get_string("tandy"),"true")!=0) &&
(strcmp(section->Get_string("tandy"),"on")!=0) &&
(strcmp(section->Get_string("tandy"),"auto")!=0)) return;
} else {
/* only enable tandy sound if tandy=true */
if ((strcmp(section->Get_string("tandy"),"true")!=0) &&
(strcmp(section->Get_string("tandy"),"on")!=0)) return;
/* ports from second DMA controller conflict with tandy ports */
CloseSecondDMAController();
if (enable_hw_tandy_dac) {
WriteHandler[2].Install(0x1e0,SN76496Write,IO_MB,2);
WriteHandler[3].Install(0x1e4,TandyDACWrite,IO_MB,4);
// ReadHandler[3].Install(0x1e4,TandyDACRead,IO_MB,4);
}
}
Bit32u sample_rate = section->Get_int("tandyrate");
tandy.chan=MixerChan.Install(&SN76496Update,sample_rate,"TANDY");
WriteHandler[0].Install(0xc0,SN76496Write,IO_MB,2);
if (enable_hw_tandy_dac) {
// enable low-level Tandy DAC emulation
WriteHandler[1].Install(0xc4,TandyDACWrite,IO_MB,4);
ReadHandler[1].Install(0xc4,TandyDACRead,IO_MB,4);
tandy.dac.enabled=true;
tandy.dac.chan=MixerChanDAC.Install(&TandyDACUpdate,sample_rate,"TANDYDAC");
tandy.dac.hw.base=0xc4;
tandy.dac.hw.irq =7;
tandy.dac.hw.dma =1;
} else {
tandy.dac.enabled=false;
tandy.dac.hw.base=0;
tandy.dac.hw.irq =0;
tandy.dac.hw.dma =0;
}
tandy.dac.control=0;
tandy.dac.mode =0;
tandy.dac.irq_activated=false;
tandy.dac.frequency=0;
tandy.dac.amplitude=0;
tandy.dac.dma.last_sample=0;
tandy.enabled=false;
real_writeb(0x40,0xd4,0xff); /* BIOS Tandy DAC initialization value */
Bitu i;
struct SN76496 *R = &sn;
R->SampleRate = sample_rate;
SN76496_set_clock(3579545);
for (i = 0;i < 4;i++) R->Volume[i] = 0;
R->LastRegister = 0;
for (i = 0;i < 8;i+=2)
{
R->Register[i] = 0;
R->Register[i + 1] = 0x0f; /* volume = 0 */
}
for (i = 0;i < 4;i++)
{
R->Output[i] = 0;
R->Period[i] = R->Count[i] = R->UpdateStep;
}
R->RNG = NG_PRESET;
R->Output[3] = R->RNG & 1;
SN76496_set_gain(0x1);
}
~TANDYSOUND(){ }
};
static TANDYSOUND* test;
void TANDYSOUND_ShutDown(Section* /*sec*/) {
delete test;
}
void TANDYSOUND_Init(Section* sec) {
test = new TANDYSOUND(sec);
sec->AddDestroyFunction(&TANDYSOUND_ShutDown,true);
}