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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<legacy_device_base *>(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);
}
DEVICE_GET_INFO( s2636_sound )
{
switch (state)
{
/* --- the following bits of info are returned as 64-bit signed integers --- */
case DEVINFO_INT_TOKEN_BYTES: info->i = sizeof(s2636_sound); break;
/* --- the following bits of info are returned as pointers to data or functions --- */
case DEVINFO_FCT_START: info->start = DEVICE_START_NAME(s2636_sound); break;
/* --- the following bits of info are returned as NULL-terminated strings --- */
case DEVINFO_STR_NAME: strcpy(info->s, "S2636"); break;
case DEVINFO_STR_SOURCE_FILE: strcpy(info->s, __FILE__); break;
}
}
DEFINE_LEGACY_SOUND_DEVICE(S2636_SOUND, s2636_sound);
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