Sprinter/mame
2
0
Fork 0
mirror of https://github.com/holub/mame synced 2025-07-05 01:48:29 +03:00
Code Issues Actions 33 Packages Projects Releases Wiki Activity

ymf278b: Allow PCM writes if new2flag is set, even if newflag is not. Fixes MT08033.

Browse Source
This commit is contained in:
Aaron Giles 2021-07-24 00:53:38 -07:00
parent 3e2915660f
commit 3d450c480d
1 changed files with 12 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

22
3rdparty/ymfm/src/ymfm_opl.cpp vendored
View File

@ -1804,11 +1804,6 @@ void ymf278b::write_address_pcm(uint8_t data)
{ {
// just set the address // just set the address
m_address = data | 0x200; m_address = data | 0x200;
// YMF262, in compatibility mode, treats the upper bit as masked
// except for register 0x105; assuming YMF278B works the same way?
if (m_fm.regs().newflag() == 0 && m_address != 0x105)
m_address &= 0xff;
} }
@ -1819,14 +1814,21 @@ void ymf278b::write_address_pcm(uint8_t data)
void ymf278b::write_data_pcm(uint8_t data) void ymf278b::write_data_pcm(uint8_t data)
{ {
// ignore data writes if new2 is not yet set
if (m_fm.regs().new2flag() == 0)
return;
// write to FM // write to FM
if (bitfield(m_address, 9) != 0) if (bitfield(m_address, 9) != 0)
m_pcm.write(m_address & 0xff, data); {
uint8_t addr = m_address & 0xff;
m_pcm.write(addr, data);
// writes to the waveform number cause loads to happen for "about 300usec" // writes to the waveform number cause loads to happen for "about 300usec"
// which is ~13 samples at the nominal output frequency of 44.1kHz // which is ~13 samples at the nominal output frequency of 44.1kHz
if (m_address >= 0x08 && m_address <= 0x1f) if (addr >= 0x08 && addr <= 0x1f)
m_load_remaining = 13; m_load_remaining = 13;
}
// BUSY goes for 88 clocks on PCM writes // BUSY goes for 88 clocks on PCM writes
m_fm.intf().ymfm_set_busy_end(88); m_fm.intf().ymfm_set_busy_end(88);