diff options
-rw-r--r-- | audio/fmopl.h | 4 | ||||
-rw-r--r-- | audio/softsynth/opl/dosbox.cpp | 27 |
2 files changed, 24 insertions, 7 deletions
diff --git a/audio/fmopl.h b/audio/fmopl.h index 323cc3d028..ad1794d873 100644 --- a/audio/fmopl.h +++ b/audio/fmopl.h @@ -129,7 +129,9 @@ public: /** * Function to directly write to a specific OPL register. - * This writes to *both* chips for a Dual OPL2. + * This writes to *both* chips for a Dual OPL2. We allow + * writing to secondary OPL registers by using register + * values >= 0x100. * * @param r hardware register number to write to * @param v value, which will be written diff --git a/audio/softsynth/opl/dosbox.cpp b/audio/softsynth/opl/dosbox.cpp index e039845b8f..a1a736f9de 100644 --- a/audio/softsynth/opl/dosbox.cpp +++ b/audio/softsynth/opl/dosbox.cpp @@ -247,7 +247,7 @@ byte OPL::read(int port) { } void OPL::writeReg(int r, int v) { - byte tempReg = 0; + int tempReg = 0; switch (_type) { case Config::kOpl2: case Config::kDualOpl2: @@ -257,12 +257,27 @@ void OPL::writeReg(int r, int v) { // Backup old setup register tempReg = _reg.normal; - // We need to set the register we want to write to via port 0x388 - write(0x388, r); - // Do the real writing to the register - write(0x389, v); + // We directly allow writing to secondary OPL3 registers by using + // register values >= 0x100. + if (_type == Config::kOpl3 && r >= 0x100) { + // We need to set the register we want to write to via port 0x222, + // since we want to write to the secondary register set. + write(0x222, r); + // Do the real writing to the register + write(0x223, v); + } else { + // We need to set the register we want to write to via port 0x388 + write(0x388, r); + // Do the real writing to the register + write(0x389, v); + } + // Restore the old register - write(0x388, tempReg); + if (_type == Config::kOpl3 && tempReg >= 0x100) { + write(0x222, tempReg & ~0x100); + } else { + write(0x388, tempReg); + } break; }; } |