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Merge pull request #1376 from jrieman/megaduck_snd_fix

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Fix Mega Duck envelope and lfsr sound registers
This commit is contained in:
R. Belmont 2016-09-08 14:12:31 -04:00 committed by GitHub
commit b810c01fce
1 changed files with 19 additions and 23 deletions
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42
src/mame/machine/gb.cpp
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@ -714,44 +714,40 @@ WRITE8_MEMBER(megaduck_state::megaduck_video_w)
}
/* Map megaduck audio offset to game boy audio offsets */
/* Envelope and LFSR register nibbles are reversed relative to the game boy */
static const UINT8 megaduck_sound_offsets[16] = { 0, 2, 1, 3, 4, 6, 5, 7, 8, 9, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F };
WRITE8_MEMBER(megaduck_state::megaduck_sound_w1)
{
m_custom->sound_w(space, megaduck_sound_offsets[offset], data);
if ((offset == 0x01) || (offset == 0x07))
m_custom->sound_w(space, megaduck_sound_offsets[offset], ((data & 0x0f)<<4) | ((data & 0xf0)>>4));
else
m_custom->sound_w(space, megaduck_sound_offsets[offset], data);
}
READ8_MEMBER(megaduck_state::megaduck_sound_r1)
{
return m_custom->sound_r(space, megaduck_sound_offsets[offset]);
UINT8 data = m_custom->sound_r(space, megaduck_sound_offsets[offset]);
if ((offset == 0x01) || (offset == 0x07))
return ((data & 0x0f)<<4) | ((data & 0xf0)>>4);
else
return data;
}
WRITE8_MEMBER(megaduck_state::megaduck_sound_w2)
{
switch(offset)
{
case 0x00: m_custom->sound_w(space, 0x10, data); break;
case 0x01: m_custom->sound_w(space, 0x12, data); break;
case 0x02: m_custom->sound_w(space, 0x11, data); break;
case 0x03: m_custom->sound_w(space, 0x13, data); break;
case 0x04: m_custom->sound_w(space, 0x14, data); break;
case 0x05: m_custom->sound_w(space, 0x16, data); break;
case 0x06: m_custom->sound_w(space, 0x15, data); break;
case 0x07:
case 0x08:
case 0x09:
case 0x0A:
case 0x0B:
case 0x0C:
case 0x0D:
case 0x0E:
case 0x0F:
break;
}
if ((offset == 0x01) || (offset == 0x02))
m_custom->sound_w(space, 0x10 + megaduck_sound_offsets[offset], ((data & 0x0f)<<4) | ((data & 0xf0)>>4));
else
m_custom->sound_w(space, 0x10 + megaduck_sound_offsets[offset], data);
}
READ8_MEMBER(megaduck_state::megaduck_sound_r2)
{
return m_custom->sound_r(space, 0x10 + megaduck_sound_offsets[offset]);
UINT8 data = m_custom->sound_r(space, 0x10 + megaduck_sound_offsets[offset]);
if ((offset == 0x01) || (offset == 0x02))
return ((data & 0x0f)<<4) | ((data & 0xf0)>>4);
else
return data;
}