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// license:GPL-2.0+
// copyright-holders:Peter Trauner
/***************************************************************************
PeT mess@utanet.at
main part in video/
***************************************************************************/
#include "vc4000snd.h"
const device_type VC4000_SND = &device_creator<vc4000_sound_device>;
vc4000_sound_device::vc4000_sound_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock)
: device_t(mconfig, VC4000_SND, "Intertion Electronic VC 4000 Audio Custom", tag, owner, clock, "vc4000_sound", __FILE__),
device_sound_interface(mconfig, *this),
m_channel(NULL),
m_size(0),
m_pos(0),
m_level(0)
{
memset(m_reg, 0, sizeof(UINT8)*1);
}
//-------------------------------------------------
// device_start - device-specific startup
//-------------------------------------------------
void vc4000_sound_device::device_start()
{
m_channel = stream_alloc(0, 1, machine().sample_rate());
}
//-------------------------------------------------
// sound_stream_update - handle a stream update
//-------------------------------------------------
void vc4000_sound_device::sound_stream_update(sound_stream &stream, stream_sample_t **inputs, stream_sample_t **outputs, int samples)
{
int i;
stream_sample_t *buffer = outputs[0];
for (i = 0; i < samples; i++, buffer++)
{
*buffer = 0;
if (m_reg[0] && m_pos <= m_size / 2)
{
*buffer = 0x7fff;
}
if (m_pos <= m_size)
m_pos++;
if (m_pos > m_size)
m_pos = 0;
}
}
void vc4000_sound_device::soundport_w(int offset, int data)
{
m_channel->update();
m_reg[offset] = data;
switch (offset)
{
case 0:
m_pos = 0;
m_level = TRUE;
// frequency 7874/(data+1)
m_size = machine().sample_rate() * (data + 1) /7874;
break;
}
}
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