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galaxian.c
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C/C++ Source or Header
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2000-05-04
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17KB
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683 lines
#include "driver.h"
#include <math.h>
#define VERBOSE 0
#define NEW_LFO 0
#define NEW_SHOOT 1
#define XTAL 18432000
#define SOUND_CLOCK (XTAL/6/2) /* 1.536 Mhz */
#define SAMPLES 1
#define RNG_RATE (XTAL/3) /* RNG clock is XTAL/3 */
#define NOISE_RATE (XTAL/3/192/2/2) /* 2V = 8kHz */
#define NOISE_LENGTH (NOISE_RATE*4) /* four seconds of noise */
#define SHOOT_RATE 2672
#define SHOOT_LENGTH 13000
#define TOOTHSAW_LENGTH 16
#define TOOTHSAW_VOLUME 36
#define STEPS 16
#define LFO_VOLUME 6
#define SHOOT_VOLUME 50
#define NOISE_VOLUME 50
#define NOISE_AMPLITUDE 70*256
#define TOOTHSAW_AMPLITUDE 64
/* see comments in galaxian_sh_update() */
#define MINFREQ (139-139/3)
#define MAXFREQ (139+139/3)
#if VERBOSE
#define LOG(x) logerror x
#else
#define LOG(x)
#endif
static void *lfotimer = 0;
static int freq = MAXFREQ;
#define STEP 1
static void *noisetimer = 0;
static int noisevolume;
static INT16 *noisewave;
static INT16 *shootwave;
#if NEW_SHOOT
static int shoot_length;
static int shoot_rate;
#endif
#if SAMPLES
static int shootsampleloaded = 0;
static int deathsampleloaded = 0;
static int last_port1=0;
#endif
static int last_port2=0;
static INT8 tonewave[4][TOOTHSAW_LENGTH];
static int pitch,vol;
static INT16 backgroundwave[32] =
{
0x4000, 0x4000, 0x4000, 0x4000, 0x4000, 0x4000, 0x4000, 0x4000,
0x4000, 0x4000, 0x4000, 0x4000, 0x4000, 0x4000, 0x4000, 0x4000,
-0x4000,-0x4000,-0x4000,-0x4000,-0x4000,-0x4000,-0x4000,-0x4000,
-0x4000,-0x4000,-0x4000,-0x4000,-0x4000,-0x4000,-0x4000,-0x4000,
};
static int channelnoise,channelshoot,channellfo;
static int tone_stream;
static void tone_update(int ch, INT16 *buffer, int length)
{
int i,j;
INT8 *w = tonewave[vol];
static int counter, countdown;
/* only update if we have non-zero volume and frequency */
if( pitch != 0xff )
{
for (i = 0; i < length; i++)
{
int mix = 0;
for (j = 0;j < STEPS;j++)
{
if (countdown >= 256)
{
counter = (counter + 1) % TOOTHSAW_LENGTH;
countdown = pitch;
}
countdown++;
mix += w[counter];
}
*buffer++ = (mix << 8) / STEPS;
}
}
else
{
for( i = 0; i < length; i++ )
*buffer++ = 0;
}
}
WRITE_HANDLER( galaxian_pitch_w )
{
stream_update(tone_stream,0);
pitch = data;
}
WRITE_HANDLER( galaxian_vol_w )
{
stream_update(tone_stream,0);
/* offset 0 = bit 0, offset 1 = bit 1 */
vol = (vol & ~(1 << offset)) | ((data & 1) << offset);
}
static void noise_timer_cb(int param)
{
if( noisevolume > 0 )
{
noisevolume -= (noisevolume / 10) + 1;
mixer_set_volume(channelnoise,noisevolume);
}
}
WRITE_HANDLER( galaxian_noise_enable_w )
{
#if SAMPLES
if (deathsampleloaded)
{
if (data & 1 && !(last_port1 & 1))
mixer_play_sample(channelnoise,Machine->samples->sample[1]->data,
Machine->samples->sample[1]->length,
Machine->samples->sample[1]->smpfreq,
0);
last_port1=data;
}
else
#endif
{
if( data & 1 )
{
if( noisetimer )
{
timer_remove(noisetimer);
noisetimer = 0;
}
noisevolume = 100;
mixer_set_volume(channelnoise,noisevolume);
}
else
{
/* discharge C21, 22uF via 150k+22k R35/R36 */
if (noisevolume == 100)
{
noisetimer = timer_pulse(TIME_IN_USEC(0.693*(155000+22000)*22 / 100), 0, noise_timer_cb);
}
}
}
}
WRITE_HANDLER( galaxian_shoot_enable_w )
{
if( data & 1 && !(last_port2 & 1) )
{
#if SAMPLES
if( shootsampleloaded )
{
mixer_play_sample(channelshoot,Machine->samples->sample[0]->data,
Machine->samples->sample[0]->length,
Machine->samples->sample[0]->smpfreq,
0);
}
else
#endif
{
#if NEW_SHOOT
mixer_play_sample_16(channelshoot, shootwave, shoot_length, shoot_rate, 0);
#else
mixer_play_sample_16(channelshoot, shootwave, SHOOT_LENGTH, 10*SHOOT_RATE, 0);
#endif
mixer_set_volume(channelshoot,SHOOT_VOLUME);
}
}
last_port2=data;
}
#if SAMPLES
static const char *galaxian_sample_names[] =
{
"*galaxian",
"shot.wav",
"death.wav",
0 /* end of array */
};
#endif
int galaxian_sh_start(const struct MachineSound *msound)
{
int i, j, sweep, charge, countdown, generator, bit1, bit2;
int lfovol[3] = {LFO_VOLUME,LFO_VOLUME,LFO_VOLUME};
#if SAMPLES
Machine->samples = readsamples(galaxian_sample_names,Machine->gamedrv->name);
#endif
channelnoise = mixer_allocate_channel(NOISE_VOLUME);
mixer_set_name(channelnoise,"Noise");
channelshoot = mixer_allocate_channel(SHOOT_VOLUME);
mixer_set_name(channelshoot,"Shoot");
channellfo = mixer_allocate_channels(3,lfovol);
mixer_set_name(channellfo+0,"Background #0");
mixer_set_name(channellfo+1,"Background #1");
mixer_set_name(channellfo+2,"Background #2");
#if SAMPLES
if (Machine->samples != 0 && Machine->samples->sample[0] != 0) /* We should check also that Samplename[0] = 0 */
shootsampleloaded = 1;
else
shootsampleloaded = 0;
if (Machine->samples != 0 && Machine->samples->sample[1] != 0) /* We should check also that Samplename[0] = 0 */
deathsampleloaded = 1;
else
deathsampleloaded = 0;
#endif
if( (noisewave = malloc(NOISE_LENGTH * sizeof(INT16))) == 0 )
{
return 1;
}
#if NEW_SHOOT
#define SHOOT_SEC 2
shoot_rate = Machine->sample_rate;
shoot_length = SHOOT_SEC * shoot_rate;
if ((shootwave = malloc(shoot_length * sizeof(INT16))) == 0)
#else
if( (shootwave = malloc(SHOOT_LENGTH * sizeof(INT16))) == 0 )
#endif
{
free(noisewave);
return 1;
}
/*
* The RNG shifter is clocked with RNG_RATE, bit 17 is
* latched every 2V cycles (every 2nd scanline).
* This signal is used as a noise source.
*/
generator = 0;
countdown = NOISE_RATE / 2;
for( i = 0; i < NOISE_LENGTH; i++ )
{
countdown -= RNG_RATE;
while( countdown < 0 )
{
generator <<= 1;
bit1 = (~generator >> 17) & 1;
bit2 = (generator >> 5) & 1;
if (bit1 ^ bit2) generator |= 1;
countdown += NOISE_RATE;
}
noisewave[i] = ((generator >> 17) & 1) ? NOISE_AMPLITUDE : -NOISE_AMPLITUDE;
}
#if NEW_SHOOT
/* dummy */
sweep = 100;
charge = +2;
j=0;
{
#define R41__ 100000
#define R44__ 10000
#define R45__ 22000
#define R46__ 10000
#define R47__ 2200
#define R48__ 2200
#define C25__ 0.000001
#define C27__ 0.00000001
#define C28__ 0.000047
#define C29__ 0.00000001
#define IC8L3_L 0.2 /* 7400 L level */
#define IC8L3_H 4.5 /* 7400 H level */
#define NOISE_L 0.2 /* 7474 L level */
#define NOISE_H 4.5 /* 7474 H level */
/*
key on/off time is programmable
Therefore, it is necessary to make separate sample with key on/off.
And, calculate the playback point according to the voltage of c28.
*/
#define SHOOT_KEYON_TIME 0.1 /* second */
/*
NE555-FM input calculation is wrong.
The frequency is not proportional to the voltage of FM input.
And, duty will be changed,too.
*/
#define NE555_FM_ADJUST_RATE 0.80
/* discharge : 100K * 1uF */
double v = 5.0;
double vK = (shoot_rate) ? exp(-1 / (R41__*C25__) / shoot_rate) : 0;
/* -- SHOOT KEY port -- */
double IC8L3 = IC8L3_L; /* key on */
int IC8Lcnt = SHOOT_KEYON_TIME * shoot_rate; /* count for key off */
/* C28 : KEY port capacity */
/* connection : 8L-3 - R47(2.2K) - C28(47u) - R48(2.2K) - C29 */
double c28v = IC8L3_H - (IC8L3_H-(NOISE_H+NOISE_L)/2)/(R46__+R47__+R48__)*R47__;
double c28K = (shoot_rate) ? exp(-1 / (22000 * 0.000047 ) / shoot_rate) : 0;
/* C29 : NOISE capacity */
/* connection : NOISE - R46(10K) - C29(0.1u) - R48(2.2K) - C28 */
double c29v = IC8L3_H - (IC8L3_H-(NOISE_H+NOISE_L)/2)/(R46__+R47__+R48__)*(R47__+R48__);
double c29K1 = (shoot_rate) ? exp(-1 / (22000 * 0.00000001 ) / shoot_rate) : 0; /* form C28 */
double c29K2 = (shoot_rate) ? exp(-1 / (100000 * 0.00000001 ) / shoot_rate) : 0; /* from noise */
/* NE555 timer */
/* RA = 10K , RB = 22K , C=.01u ,FM = C29 */
double ne555cnt = 0;
double ne555step = (shoot_rate) ? ((1.44/((R44__+R45__*2)*C27__)) / shoot_rate) : 0;
double ne555duty = (double)(R44__+R45__)/(R44__+R45__*2); /* t1 duty */
double ne555sr; /* threshold (FM) rate */
/* NOISE source */
double ncnt = 0.0;
double nstep = (shoot_rate) ? ((double)NOISE_RATE / shoot_rate) : 0;
double noise_sh2; /* voltage level */
for( i = 0; i < shoot_length; i++ )
{
/* noise port */
noise_sh2 = noisewave[(int)ncnt % NOISE_LENGTH] == NOISE_AMPLITUDE ? NOISE_H : NOISE_L;
ncnt+=nstep;
/* calculate NE555 threshold level by FM input */
ne555sr = c29v*NE555_FM_ADJUST_RATE / (5.0*2/3);
/* calc output */
ne555cnt += ne555step;
if( ne555cnt >= ne555sr) ne555cnt -= ne555sr;
if( ne555cnt < ne555sr*ne555duty )
{
/* t1 time */
shootwave[i] = v/5*0x7fff;
/* discharge output level */
if(IC8L3==IC8L3_H)
v *= vK;
}
else
shootwave[i] = 0;
/* C28 charge/discharge */
c28v += (IC8L3-c28v) - (IC8L3-c28v)*c28K; /* from R47 */
c28v += (c29v-c28v) - (c29v-c28v)*c28K; /* from R48 */
/* C29 charge/discharge */
c29v += (c28v-c29v) - (c28v-c29v)*c29K1; /* from R48 */
c29v += (noise_sh2-c29v) - (noise_sh2-c29v)*c29K2; /* from R46 */
/* key off */
if(IC8L3==IC8L3_L && --IC8Lcnt==0)
IC8L3=IC8L3_H;
}
}
#else
/*
* Ra is 10k, Rb is 22k, C is 0.01uF
* charge time t1 = 0.693 * (Ra + Rb) * C -> 221.76us
* discharge time t2 = 0.693 * (Rb) * C -> 152.46us
* average period 374.22us -> 2672Hz
* I use an array of 10 values to define some points
* of the charge/discharge curve. The wave is modulated
* using the charge/discharge timing of C28, a 47uF capacitor,
* over a 2k2 resistor. This will change the frequency from
* approx. Favg-Favg/3 up to Favg+Favg/3 down to Favg-Favg/3 again.
*/
sweep = 100;
charge = +2;
countdown = sweep / 2;
for( i = 0, j = 0; i < SHOOT_LENGTH; i++ )
{
#define AMP(n) (n)*0x8000/100-0x8000
static int charge_discharge[10] = {
AMP( 0), AMP(25), AMP(45), AMP(60), AMP(70), AMP(85),
AMP(70), AMP(50), AMP(25), AMP( 0)
};
shootwave[i] = charge_discharge[j];
LOG(("shoot[%5d] $%04x (sweep: %3d, j:%d)\n", i, shootwave[i] & 0xffff, sweep, j));
/*
* The current sweep and a 2200/10000 fraction (R45 and R48)
* of the noise are frequency modulating the NE555 chip.
*/
countdown -= sweep + noisewave[i % NOISE_LENGTH] / (2200*NOISE_AMPLITUDE/10000);
while( countdown < 0 )
{
countdown += 100;
j = ++j % 10;
}
/* sweep from 100 to 133 and down to 66 over the time of SHOOT_LENGTH */
if( i % (SHOOT_LENGTH / 33 / 3 ) == 0 )
{
sweep += charge;
if( sweep >= 133 )
charge = -1;
}
}
#endif
memset(tonewave, 0, sizeof(tonewave));
for( i = 0; i < TOOTHSAW_LENGTH; i++ )
{
#define V(r0,r1) 2*TOOTHSAW_AMPLITUDE*(r0)/(r0+r1)-TOOTHSAW_AMPLITUDE
double r0a = 1.0/1e12, r1a = 1.0/1e12;
double r0b = 1.0/1e12, r1b = 1.0/1e12;
/* #0: VOL1=0 and VOL2=0
* only the 33k and the 22k resistors R51 and R50
*/
if( i & 1 )
{
r1a += 1.0/33000;
r1b += 1.0/33000;
}
else
{
r0a += 1.0/33000;
r0b += 1.0/33000;
}
if( i & 4 )
{
r1a += 1.0/22000;
r1b += 1.0/22000;
}
else
{
r0a += 1.0/22000;
r0b += 1.0/22000;
}
tonewave[0][i] = V(1.0/r0a, 1.0/r1a);
/* #1: VOL1=1 and VOL2=0
* add the 10k resistor R49 for bit QC
*/
if( i & 4 )
r1a += 1.0/10000;
else
r0a += 1.0/10000;
tonewave[1][i] = V(1.0/r0a, 1.0/r1a);
/* #2: VOL1=0 and VOL2=1
* add the 15k resistor R52 for bit QD
*/
if( i & 8 )
r1b += 1.0/15000;
else
r0b += 1.0/15000;
tonewave[2][i] = V(1.0/r0b, 1.0/r1b);
/* #3: VOL1=1 and VOL2=1
* add the 10k resistor R49 for QC
*/
if( i & 4 )
r0b += 1.0/10000;
else
r1b += 1.0/10000;
tonewave[3][i] = V(1.0/r0b, 1.0/r1b);
LOG(("tone[%2d]: $%02x $%02x $%02x $%02x\n", i, tonewave[0][i], tonewave[1][i], tonewave[2][i], tonewave[3][i]));
}
pitch = 0;
vol = 0;
tone_stream = stream_init("Tone",TOOTHSAW_VOLUME,SOUND_CLOCK/STEPS,0,tone_update);
#if SAMPLES
if (!deathsampleloaded)
#endif
{
mixer_set_volume(channelnoise,0);
mixer_play_sample_16(channelnoise,noisewave,NOISE_LENGTH,NOISE_RATE,1);
}
#if SAMPLES
if (!shootsampleloaded)
#endif
{
mixer_set_volume(channelshoot,0);
mixer_play_sample_16(channelshoot,shootwave,SHOOT_LENGTH,SHOOT_RATE,1);
}
mixer_set_volume(channellfo+0,0);
mixer_play_sample_16(channellfo+0,backgroundwave,sizeof(backgroundwave),1000,1);
mixer_set_volume(channellfo+1,0);
mixer_play_sample_16(channellfo+1,backgroundwave,sizeof(backgroundwave),1000,1);
mixer_set_volume(channellfo+2,0);
mixer_play_sample_16(channellfo+2,backgroundwave,sizeof(backgroundwave),1000,1);
return 0;
}
void galaxian_sh_stop(void)
{
if( lfotimer )
{
timer_remove( lfotimer );
lfotimer = 0;
}
if( noisetimer )
{
timer_remove(noisetimer);
noisetimer = 0;
}
mixer_stop_sample(channelnoise);
mixer_stop_sample(channelshoot);
mixer_stop_sample(channellfo+0);
mixer_stop_sample(channellfo+1);
mixer_stop_sample(channellfo+2);
free(noisewave);
noisewave = 0;
free(shootwave);
shootwave = 0;
}
WRITE_HANDLER( galaxian_background_enable_w )
{
mixer_set_volume(channellfo+offset,(data & 1) ? 100 : 0);
}
static void lfo_timer_cb(int param)
{
if( freq > MINFREQ )
freq--;
else
freq = MAXFREQ;
}
WRITE_HANDLER( galaxian_lfo_freq_w )
{
#if NEW_LFO
static int lfobit[4];
/* R18 1M,R17 470K,R16 220K,R15 100K */
const int rv[4] = { 1000000,470000,220000,100000};
double r1,r2,Re,td;
int i;
if( (data & 1) == lfobit[offset] )
return;
/*
* NE555 9R is setup as astable multivibrator
* - this circuit looks LINEAR RAMP V-F converter
I = 1/Re * ( R1/(R1+R2)-Vbe)
td = (2/3VCC*Re*(R1+R2)*C) / (R1*VCC-Vbe*(R1+R2))
parts assign
R1 : (R15* L1)|(R16* L2)|(R17* L3)|(R18* L1)
R2 : (R15*~L1)|(R16*~L2)|(R17*~L3)|(R18*~L4)|R??(330K)
Re : R21(100K)
Vbe : Q2(2SA1015)-Vbe
* - R20(15K) and Q1 is unknown,maybe current booster.
*/
lfobit[offset] = data & 1;
/* R20 15K */
r1 = 1e12;
/* R19? 330k to gnd */
r2 = 330000;
//r1 = 15000;
/* R21 100K */
Re = 100000;
/* register calculation */
for(i=0;i<4;i++)
{
if(lfobit[i])
r1 = (r1*rv[i])/(r1+rv[i]); /* Hi */
else
r2 = (r2*rv[i])/(r2+rv[i]); /* Low */
}
if( lfotimer )
{
timer_remove( lfotimer );
lfotimer = 0;
}
#define Vcc 5.0
#define Vbe 0.65 /* 2SA1015 */
#define Cap 0.000001 /* C15 1uF */
td = (Vcc*2/3*Re*(r1+r2)*Cap) / (r1*Vcc - Vbe*(r1+r2) );
#undef Cap
#undef Vbe
#undef Vcc
logerror("lfo timer bits:%d%d%d%d r1:%d, r2:%d, re: %d, td: %9.2fsec\n", lfobit[0], lfobit[1], lfobit[2], lfobit[3], (int)r1, (int)r2, (int)Re, td);
lfotimer = timer_pulse( TIME_IN_SEC(td / (MAXFREQ-MINFREQ)), 0, lfo_timer_cb);
#else
static int lfobit[4];
double r0, r1, rx = 100000.0;
if( (data & 1) == lfobit[offset] )
return;
/*
* NE555 9R is setup as astable multivibrator
* - Ra is between 100k and ??? (open?)
* - Rb is zero here (bridge between pins 6 and 7)
* - C is 1uF
* charge time t1 = 0.693 * (Ra + Rb) * C
* discharge time t2 = 0.693 * (Rb) * C
* period T = t1 + t2 = 0.693 * (Ra + 2 * Rb) * C
* -> min period: 0.693 * 100 kOhm * 1uF -> 69300 us = 14.4Hz
* -> max period: no idea, since I don't know the max. value for Ra :(
*/
lfobit[offset] = data & 1;
/* R?? 330k to gnd */
r0 = 1.0/330000;
/* open is a very high value really ;-) */
r1 = 1.0/1e12;
/* R18 1M */
if( lfobit[0] )
r1 += 1.0/1000000;
else
r0 += 1.0/1000000;
/* R17 470k */
if( lfobit[1] )
r1 += 1.0/470000;
else
r0 += 1.0/470000;
/* R16 220k */
if( lfobit[2] )
r1 += 1.0/220000;
else
r0 += 1.0/220000;
/* R15 100k */
if( lfobit[3] )
r1 += 1.0/100000;
else
r0 += 1.0/100000;
if( lfotimer )
{
timer_remove( lfotimer );
lfotimer = 0;
}
r0 = 1.0/r0;
r1 = 1.0/r1;
/* I used an arbitrary value for max. Ra of 2M */
rx = rx + 2000000.0 * r0 / (r0+r1);
LOG(("lfotimer bits:%d%d%d%d r0:%d, r1:%d, rx: %d, time: %9.2fus\n", lfobit[3], lfobit[2], lfobit[1], lfobit[0], (int)r0, (int)r1, (int)rx, 0.639 * rx));
lfotimer = timer_pulse( TIME_IN_USEC(0.639 * rx / (MAXFREQ-MINFREQ)), 0, lfo_timer_cb);
#endif
}
void galaxian_sh_update(void)
{
/*
* NE555 8R, 8S and 8T are used as pulse position modulators
* FS1 Ra=100k, Rb=470k and C=0.01uF
* -> 0.693 * 1040k * 0.01uF -> 7207.2us = 139Hz
* FS2 Ra=100k, Rb=330k and C=0.01uF
* -> 0.693 * 760k * 0.01uF -> 5266.8us = 190Hz
* FS2 Ra=100k, Rb=220k and C=0.01uF
* -> 0.693 * 540k * 0.01uF -> 3742.2us = 267Hz
*/
mixer_set_sample_frequency(channellfo+0, sizeof(backgroundwave)*freq*(100+2*470)/(100+2*470) );
mixer_set_sample_frequency(channellfo+1, sizeof(backgroundwave)*freq*(100+2*300)/(100+2*470) );
mixer_set_sample_frequency(channellfo+2, sizeof(backgroundwave)*freq*(100+2*220)/(100+2*470) );
}