Refactored DOS support

2 files changed, 211 insertions, 0 deletions

diff --git a/src/chips/dos_hw_opl.cpp b/src/chips/dos_hw_opl.cpp
new file mode 100644
index 0000000..a9f4765
--- /dev/null
+++ b/src/chips/dos_hw_opl.cpp
@@ -0,0 +1,163 @@
+/*
+ * Interfaces over Yamaha OPL3 (YMF262) chip emulators
+ *
+ * Copyright (c) 2017-2025 Vitaly Novichkov (Wohlstand)
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <assert.h>
+#ifdef __DJGPP__
+#   include <pc.h>
+#endif
+
+#include "dos_hw_opl.h"
+
+static uint16_t                 s_OPLBase[2]    = {0x388, 0x38A};
+static char                     s_devName[80]   = {0};
+static OPLChipBase::ChipType    s_type          = OPLChipBase::CHIPTYPE_OPL3;
+static bool                     s_detected      = false;
+
+static void s_updateDevName()
+{
+    const char *oplName = (s_type == OPLChipBase::CHIPTYPE_OPL3) ? "OPL3" : "OPL2";
+    memset(s_devName, 0, sizeof(s_devName));
+    snprintf(s_devName, 80, "%s at 0x%03X", oplName, s_OPLBase[0]);
+}
+
+static void s_detect()
+{
+    if(s_detected)
+        return;
+
+    const char *blaster = getenv("BLASTER");
+    if(blaster)
+    {
+        size_t len = strlen(blaster);
+        for(size_t i = 0; i < len - 1; ++i)
+        {
+            if(blaster[i] == 'T')
+            {
+                switch(blaster[i + 1])
+                {
+                case '1':
+                case '2':
+                    s_type = OPLChipBase::CHIPTYPE_OPL2;
+                    break;
+                case '3':
+                case '4':
+                case '6':
+                    s_type = OPLChipBase::CHIPTYPE_OPL3;
+                    break;
+                default:
+                    s_type = OPLChipBase::CHIPTYPE_OPL2;
+                    break;
+                }
+
+                // printf("-- Detected BLASTER T%c\n", blaster[i + 1]);
+
+                break;
+            }
+        }
+    }
+    else
+        s_type = OPLChipBase::CHIPTYPE_OPL2;
+
+    s_detected = true;
+}
+
+DOS_HW_OPL::DOS_HW_OPL()
+{
+    s_detect();
+    s_updateDevName();
+}
+
+void DOS_HW_OPL::setOplAddress(uint16_t address)
+{
+    s_OPLBase[0] = address;
+    s_OPLBase[1] = address + 2;
+    s_updateDevName();
+}
+
+void DOS_HW_OPL::setChipType(ChipType type)
+{
+    s_type = type;
+    s_detected = true; // Assignd manually, no need to detect
+}
+
+DOS_HW_OPL::~DOS_HW_OPL()
+{
+    DOS_HW_OPL::writeReg(0x0BD, 0);
+    if(s_type == CHIPTYPE_OPL3)
+    {
+        DOS_HW_OPL::writeReg(0x104, 0);
+        DOS_HW_OPL::writeReg(0x105, 0);
+    }
+}
+
+void DOS_HW_OPL::writeReg(uint16_t addr, uint8_t data)
+{
+    assert(m_id <= 1);
+    unsigned o = addr >> 8;
+    unsigned port = s_OPLBase[m_id] + o * 2;
+
+#   ifdef __DJGPP__
+    outportb(port, addr);
+
+    for(unsigned c = 0; c < 6; ++c)
+        inportb(port);
+
+    outportb(port + 1, data);
+
+    for(unsigned c = 0; c < 35; ++c)
+        inportb(port);
+#   endif
+
+#   ifdef __WATCOMC__
+    outp(port, addr);
+
+    for(uint16_t c = 0; c < 6; ++c)
+        inp(port);
+
+    outp(port + 1, data);
+
+    for(uint16_t c = 0; c < 35; ++c)
+        inp(port);
+#   endif//__WATCOMC__
+}
+
+void DOS_HW_OPL::nativeGenerate(int16_t *frame)
+{
+    frame[0] = 0;
+    frame[1] = 0;
+}
+
+const char *DOS_HW_OPL::emulatorName()
+{
+    return s_devName;
+}
+
+bool DOS_HW_OPL::hasFullPanning()
+{
+    return false;
+}
+
+OPLChipBase::ChipType DOS_HW_OPL::chipType()
+{
+    return s_type;
+}
diff --git a/src/chips/dos_hw_opl.h b/src/chips/dos_hw_opl.h
new file mode 100644
index 0000000..5e3750b
--- /dev/null
+++ b/src/chips/dos_hw_opl.h
@@ -0,0 +1,48 @@
+/*
+ * Interfaces over Yamaha OPL3 (YMF262) chip emulators
+ *
+ * Copyright (c) 2017-2025 Vitaly Novichkov (Wohlstand)
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+
+#ifndef DOS_HW_OPL_H
+#define DOS_HW_OPL_H
+
+#include "opl_chip_base.h"
+
+class DOS_HW_OPL : public OPLChipBaseT<DOS_HW_OPL>
+{
+public:
+    DOS_HW_OPL();
+    virtual ~DOS_HW_OPL() override;
+
+    static void setChipType(ChipType type);
+    static void setOplAddress(uint16_t address);
+
+    bool canRunAtPcmRate() const override { return false; }
+    void setRate(uint32_t /*rate*/) override {}
+    void reset() override {}
+    void writeReg(uint16_t addr, uint8_t data) override;
+    void nativePreGenerate() override {}
+    void nativePostGenerate() override {}
+    void nativeGenerate(int16_t *frame) override;
+    const char *emulatorName() override;
+    ChipType chipType() override;
+    bool hasFullPanning() override;
+};
+
+#endif // DOS_HW_OPL_H