From f54d9a5840f38422347f87d5e352480764373cb0 Mon Sep 17 00:00:00 2001
From: wbcbz7 <wbcbz7.at@gmail.com>
Date: Sat, 21 Mar 2026 20:34:00 +0700
Subject: [PATCH] SB: add registers for setting DSP version, IRQ/DMA settings
 readback and emulation options

---
 common/picogus.h |  4 ++++
 sw/picogus.cpp   | 37 +++++++++++++++++++++++++++++++++++--
 2 files changed, 39 insertions(+), 2 deletions(-)

diff --git a/common/picogus.h b/common/picogus.h
index b84af96..b874baa 100644
--- a/common/picogus.h
+++ b/common/picogus.h
@@ -68,6 +68,10 @@ static const char *modenames[8] = {
 #define CMD_MPUFAKE    0x22 // MPU fake all notes off
 
 #define CMD_OPLWAIT    0x30 // Adlib speed sensitive fix
+#define CMD_SBOPTS     0x30 // SB options (mixer lock, time constant fix, etc.) - aliased to CMD_OPLWAIT
+#define CMD_SBDSPVER   0x31 // SB DSP version
+#define CMD_SBIRQ      0x32 // SB IRQ
+#define CMD_SBDMA      0x33 // SB DMA
 
 #define CMD_MOUSEPORT  0x40 // Mouse Base port
 #define CMD_MOUSEPROTO 0x41 // Mouse protocol
diff --git a/sw/picogus.cpp b/sw/picogus.cpp
index 6c75e82..3738974 100644
--- a/sw/picogus.cpp
+++ b/sw/picogus.cpp
@@ -172,7 +172,8 @@ void processSettings(void);
 const char* firmware_string = PICO_PROGRAM_NAME " v" PICO_PROGRAM_VERSION_STRING;
 
 static uint8_t basePort_low;
-static uint8_t  mouseSensitivity_low;
+static uint8_t mouseSensitivity_low;
+static uint8_t picogus_dataLatch_low;
 
 __force_inline void select_picogus(uint8_t value) {
     // printf("select picogus %x\n", value);
@@ -243,6 +244,13 @@ __force_inline void select_picogus(uint8_t value) {
         cur_read_idx = 0;
 #endif
         break;
+#ifdef SOUND_SB
+    case CMD_SBDSPVER:
+        picogus_dataLatch_low = 0;
+    case CMD_SBIRQ:
+    case CMD_SBDMA:
+        break;
+#endif
     case CMD_CDSTATUS:
     case CMD_CDLOAD:
     case CMD_CDAUTOADV:
@@ -288,6 +296,12 @@ __force_inline void write_picogus_low(uint8_t value) {
     case CMD_MOUSESEN:  // USB Mouse Sensitivity (8.8 fixedpoint)
         mouseSensitivity_low = value;
         break;
+#ifdef SOUND_SB
+    case CMD_SBDSPVER:
+        picogus_dataLatch_low = value;
+        break;
+#endif
+        break;
     }
 }
 
@@ -358,7 +372,26 @@ __force_inline void write_picogus_high(uint8_t value) {
 #endif
         break;
     case CMD_OPLWAIT: // Adlib speed sensitive fix
-        settings.SB.oplSpeedSensitive = value;
+    //case CMD_SBOPTS:  // ... and SB emulation options
+        settings.SB.oplSpeedSensitive = value & 1;  // HACK until settings struct resolved
+#ifdef SOUND_SB
+        sbdsp_set_options(value);
+#endif
+        break;
+    case CMD_SBDSPVER:
+#ifdef SOUND_SB
+        sbdsp_set_dsp_version((value << 8) | picogus_dataLatch_low);
+#endif
+        break;
+    case CMD_SBIRQ:
+#ifdef SOUND_SB
+        sbdsp_set_irq(value);
+#endif
+        break;
+    case CMD_SBDMA:
+#ifdef SOUND_SB
+        sbdsp_set_dma(value);
+#endif
         break;
     case CMD_MOUSEPORT:  // USB Mouse port (0 - disabled)
         settings.Mouse.basePort = (value || basePort_low) ? ((value << 8) | basePort_low) : 0xFFFF;