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/***************************************************************************
PeT mess@utanet.at
***************************************************************************/
#include "emu.h"
#include "sound/s2636.h"
typedef struct _s2636_sound s2636_sound;
struct _s2636_sound
{
sound_stream *channel;
UINT8 reg[1];
int size, pos;
unsigned level;
};
static s2636_sound *get_token(device_t *device)
{
assert(device != NULL);
assert(device->type() == S2636_SOUND);
return (s2636_sound *) downcast<s2636_sound_device *>(device)->token();
}
void s2636_soundport_w (device_t *device, int offset, int data)
{
s2636_sound *token = get_token(device);
token->channel->update();
token->reg[offset] = data;
switch (offset)
{
case 0:
token->pos = 0;
token->level = TRUE;
// frequency 7874/(data+1)
token->size = device->machine().sample_rate() * (data + 1) /7874;
break;
}
}
/************************************/
/* Sound handler update */
/************************************/
static STREAM_UPDATE( s2636_update )
{
int i;
s2636_sound *token = get_token(device);
stream_sample_t *buffer = outputs[0];
for (i = 0; i < samples; i++, buffer++)
{
*buffer = 0;
if (token->reg[0] && token->pos <= token->size / 2)
{
*buffer = 0x7fff;
}
if (token->pos <= token->size)
token->pos++;
if (token->pos > token->size)
token->pos = 0;
}
}
/************************************/
/* Sound handler start */
/************************************/
static DEVICE_START(s2636_sound)
{
s2636_sound *token = get_token(device);
memset(token, 0, sizeof(*token));
token->channel = device->machine().sound().stream_alloc(*device, 0, 1, device->machine().sample_rate(), 0, s2636_update);
}
const device_type S2636_SOUND = &device_creator<s2636_sound_device>;
s2636_sound_device::s2636_sound_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock)
: device_t(mconfig, S2636_SOUND, "S2636", tag, owner, clock),
device_sound_interface(mconfig, *this)
{
m_token = global_alloc_array_clear(UINT8, sizeof(s2636_sound));
}
//-------------------------------------------------
// device_config_complete - perform any
// operations now that the configuration is
// complete
//-------------------------------------------------
void s2636_sound_device::device_config_complete()
{
}
//-------------------------------------------------
// device_start - device-specific startup
//-------------------------------------------------
void s2636_sound_device::device_start()
{
DEVICE_START_NAME( s2636_sound )(this);
}
//-------------------------------------------------
// sound_stream_update - handle a stream update
//-------------------------------------------------
void s2636_sound_device::sound_stream_update(sound_stream &stream, stream_sample_t **inputs, stream_sample_t **outputs, int samples)
{
// should never get here
fatalerror("sound_stream_update called; not applicable to legacy sound devices\n");
}
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