c6280.cpp : Fix LFO

<<1 is same at patent, not +1 (reference:https://patents.google.com/patent/US4924744A/)
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cam900 2018-04-27 17:46:34 +09:00 committed by Vas Crabb
parent 636481edbd
commit 5943373e91

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@ -130,7 +130,7 @@ void c6280_device::sound_stream_update(sound_stream &stream, stream_sample_t **i
m_channel[1].m_counter &= 0x1FFFF;
lfo_data = m_channel[1].m_waveform[lfooffset];
if (m_lfo_control & 3)
step += ((lfo_data - 16) << ((m_lfo_control-1)+1)); // verified from patent, TODO : same in real hardware?
step += ((lfo_data - 16) << ((m_lfo_control-1)<<1)); // verified from patent, TODO : same in real hardware?
offset = (m_channel[0].m_counter >> 12) & 0x1F;
m_channel[0].m_counter += m_wave_freq_tab[step & 0xfff];