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Diffstat (limited to 'src/mame/interton/vc4000_a.cpp')
-rw-r--r-- | src/mame/interton/vc4000_a.cpp | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/src/mame/interton/vc4000_a.cpp b/src/mame/interton/vc4000_a.cpp new file mode 100644 index 00000000000..418ec6ee8c5 --- /dev/null +++ b/src/mame/interton/vc4000_a.cpp @@ -0,0 +1,68 @@ +// license:GPL-2.0+ +// copyright-holders:Peter Trauner +/*************************************************************************** + + PeT mess@utanet.at + main part in video/ + +***************************************************************************/ + +#include "emu.h" +#include "vc4000_a.h" + + +DEFINE_DEVICE_TYPE(VC4000_SND, vc4000_sound_device, "vc4000_sound", "Interton Electronic VC 4000 Custom Sound") + +vc4000_sound_device::vc4000_sound_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) + : device_t(mconfig, VC4000_SND, tag, owner, clock) + , device_sound_interface(mconfig, *this) + , m_channel(nullptr) + , m_reg{ 0 } + , m_size(0) + , m_pos(0) + , m_level(0) +{ +} + + +//------------------------------------------------- +// 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) +{ + for (int i = 0; i < stream.samples(); i++) + { + stream.put(0, i, (m_reg[0] && m_pos <= m_size / 2) ? 1.0 : 0.0); + 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; + } +} |