Volume control

common/picogus.h

@@ -88,6 +88,13 @@ static const char *modenames[8] = {
 #define MODE_CDNAME     0x65 // Get name of loaded CD image
 #define MODE_CDAUTOADV  0x66 // Set autoadvance for CD image on USB reinsert
 
+#define MODE_MAINVOL    0x70 // Main Volume
+#define MODE_OPLVOL     0x71 // Adlib volume
+#define MODE_SBVOL      0x72 // Sound Blaster volume
+#define MODE_CDVOL      0x73 // CD Audio Volume
+#define MODE_GUSVOL     0x74 // GUS Volume
+#define MODE_PSGVOL     0x75 // PSG Volume
+
 #define MODE_DEFAULTS   0xE0 // Select reset to defaults register
 #define MODE_SAVE       0xE1 // Select save settings register
 #define MODE_REBOOT     0xE2 // Select reboot register

pgusinit/pgusinit.c

@@ -42,6 +42,7 @@ static void usage(card_mode_t mode, bool print_all) {
     printf("   /defaults     - set all settings for all modes to defaults\n");
     printf("   /wtvol x      - set volume of WT header. 0-100, Default 100 (2.0 cards only)\n");
     printf("   /joy 1|0      - enable/disable USB joystick support, Default: 0\n");
+    printf("   /mainvol x    - set the main audio volume: 0 - 100\n");
     //     "...............................................................................\n"
     printf("MPU-401 settings:\n");
     printf("   /mpuport x    - set the base port of the MPU-401. Default: 330, 0 to disable\n");
@@ -57,16 +58,19 @@ static void usage(card_mode_t mode, bool print_all) {
         printf("                 Specifying 0 restores the GUS default behavior.\n");
         printf("                 (increase to fix games with streaming audio like Doom)\n");
         printf("   /gus44k 1|0 - Fixed 44.1kHz output for all active voice #s [EXPERIMENTAL]\n");
+        printf("   /gusvol x   - set the GUS audio volume: 0 - 100\n");
     }
     if (mode == SB_MODE || print_all) {
         //     "...............................................................................\n"
         printf("Sound Blaster settings:\n");
         printf("   /sbport x    - set the base port of the Sound Blaster. Default: 220\n");
+        printf("   /sbvol x     - set the Sound Blaster audio volume: 0 - 100%\n");
     }
     if (mode == SB_MODE || mode == ADLIB_MODE || print_all) {
         printf("AdLib settings:\n");
         printf("   /oplport x   - set the base port of the OPL2. Default: 388, 0 to disable\n");
         printf("   /oplwait 1|0 - wait on OPL2 write. Can fix speed-sensitive early AdLib games\n");
+        printf("   /oplvol x    - set the OPL2 audio volume: 0 - 100\n");
     }
     if (mode == SB_MODE || mode == USB_MODE || print_all) {
         printf("CD-ROM settings:\n");
@@ -74,17 +78,20 @@ static void usage(card_mode_t mode, bool print_all) {
         printf("   /cdlist       - list CD images on the inserted USB drive\n");
         printf("   /cdload n     - load image n in the list given by /cdlist. 0 to unload image\n");
         printf("   /cdloadname x - load CD image by name. Names with spaces can be quoted\n");
+        printf("   /cdvol n      - set the CD audio volume: 0 - 100\n");
         printf("   /cdauto 1|0   - auto-advance loaded image when same USB drive is reinserted\n");
     }
     if (mode == PSG_MODE || print_all) {
         //     "...............................................................................\n"
         printf("Tandy settings:\n");
         printf("   /tandyport x - set the base port of the Tandy 3-voice. Default: 2C0\n");
+        printf("   /psgvol x    - set the PSG audio volume: 0 - 100\n");
     }
     if (mode == PSG_MODE || print_all) {
         //     "...............................................................................\n"
         printf("CMS settings:\n");
         printf("   /cmsport x - set the base port of the CMS. Default: 220\n");
+        printf("   /psgvol x  - set the PSG audio volume: 0 - 100\n");
     }
     if (mode == USB_MODE || mode == PSG_MODE || mode == ADLIB_MODE || print_all) {
         //     "...............................................................................\n"
@@ -326,7 +333,10 @@ static void print_cdemu_status(void) {
     uint8_t tmp_uint8 = inp(DATA_PORT_HIGH);
     outp(CONTROL_PORT, MODE_CDPORT); // Select port register
     uint16_t tmp_uint16 = inpw(DATA_PORT_LOW); // Get port
-    printf("CD-ROM emulation on port %x, image auto-advance %s\n", tmp_uint16, tmp_uint8 ? "enabled" : "disabled");
+    outp(CONTROL_PORT, MODE_CDVOL); // Select CD volume register
+    uint16_t tmp_vol = inp(DATA_PORT_HIGH);
+    printf("CD-ROM emulation on port %x, image auto-advance %s\nCD-Audio Volume: %u%\n", tmp_uint16, tmp_uint8 ? "enabled" : "disabled", tmp_vol);
+    
     print_cdimage_current();
 }
 
@@ -508,7 +518,6 @@ static void send_string(uint8_t mode, char* str, int16_t max_len)
     outp(DATA_PORT_HIGH, 0);
 }
 
-
 #define process_bool_opt(option) \
 if (i + 1 >= argc) { \
     usage(mode, false); \
@@ -833,6 +842,78 @@ int main(int argc, char* argv[]) {
             process_bool_opt(tmp_uint8);
             outp(CONTROL_PORT, MODE_CDAUTOADV); // Select CD image autoadvance register
             outp(DATA_PORT_HIGH, tmp_uint8);
+        } else if (stricmp(argv[i], "/mainvol") == 0) {
+            if (i + 1 >= argc) {
+                usage(mode, false);
+                return 255;
+            }
+            e = sscanf(argv[++i], "%hhu", &tmp_uint8);
+            if (e != 1 || tmp_uint8 > 100) {
+                usage(mode, false);
+                return 4;
+            }
+            outp(CONTROL_PORT, MODE_MAINVOL); // Set the volume for all outputs
+            outp(DATA_PORT_HIGH, tmp_uint8);
+        } else if (stricmp(argv[i], "/oplvol") == 0) {
+            if (i + 1 >= argc) {
+                usage(mode, false);
+                return 255;
+            }
+            e = sscanf(argv[++i], "%hhu", &tmp_uint8);
+            if (e != 1 || tmp_uint8 > 100) {
+                usage(mode, false);
+                return 4;
+            }
+            outp(CONTROL_PORT, MODE_OPLVOL); // Set the volume for Sound Blaster
+            outp(DATA_PORT_HIGH, tmp_uint8);
+        } else if (stricmp(argv[i], "/sbvol") == 0) {
+            if (i + 1 >= argc) {
+                usage(mode, false);
+                return 255;
+            }
+            e = sscanf(argv[++i], "%hhu", &tmp_uint8);
+            if (e != 1 || tmp_uint8 > 100) {
+                usage(mode, false);
+                return 4;
+            }
+            outp(CONTROL_PORT, MODE_SBVOL); // Set the volume for Sound Blaster
+            outp(DATA_PORT_HIGH, tmp_uint8);
+        } else if (stricmp(argv[i], "/cdvol") == 0) {
+            if (i + 1 >= argc) {
+                usage(mode, false);
+                return 255;
+            }
+            e = sscanf(argv[++i], "%hhu", &tmp_uint8);
+            if (e != 1 || tmp_uint8 > 100) {
+                usage(mode, false);
+                return 4;
+            }
+            outp(CONTROL_PORT, MODE_CDVOL); // Set the volume for CD Audio
+            outp(DATA_PORT_HIGH, tmp_uint8); 
+        } else if (stricmp(argv[i], "/gusvol") == 0) {
+            if (i + 1 >= argc) {
+                usage(mode, false);
+                return 255;
+            }
+            e = sscanf(argv[++i], "%hhu", &tmp_uint8);
+            if (e != 1 || tmp_uint8 > 100) {
+                usage(mode, false);
+                return 4;
+            }
+            outp(CONTROL_PORT, MODE_GUSVOL); // Set the volume for GUS
+            outp(DATA_PORT_HIGH, tmp_uint8);   
+        } else if (stricmp(argv[i], "/psgvol") == 0) {
+            if (i + 1 >= argc) {
+                usage(mode, false);
+                return 255;
+            }
+            e = sscanf(argv[++i], "%hhu", &tmp_uint8);
+            if (e != 1 || tmp_uint8 > 100) {
+                usage(mode, false);
+                return 4;
+            }
+            outp(CONTROL_PORT, MODE_PSGVOL); // Set the volume for PSG
+            outp(DATA_PORT_HIGH, tmp_uint8);     
         } else {
             printf("Unknown option: %s\n", argv[i]);
             usage(mode, false);
@@ -929,6 +1010,11 @@ int main(int argc, char* argv[]) {
         outp(CONTROL_PORT, MODE_GUSPORT); // Select port register
         tmp_uint16 = inpw(DATA_PORT_LOW); // Get port
         printf("Running in GUS mode on port %x\n", tmp_uint16);
+        outp(CONTROL_PORT, MODE_GUSVOL); // Select GUS volume register
+        tmp_uint8 = inp(DATA_PORT_HIGH);
+        outp(CONTROL_PORT, MODE_MAINVOL); // Select Main volume register
+        tmp_uint16 = inp(DATA_PORT_HIGH);
+        printf("Volume:     GUS: %u     Main: %u\n", tmp_uint8, tmp_uint16);
         break;
     case ADLIB_MODE:
         outp(CONTROL_PORT, MODE_OPLPORT); // Select port register
@@ -952,6 +1038,11 @@ int main(int argc, char* argv[]) {
         outp(CONTROL_PORT, MODE_CMSPORT); // Select port register
         tmp_uint16 = inpw(DATA_PORT_LOW); // Get port
         printf("CMS/Game Blaster on port %x)\n", tmp_uint16);
+        outp(CONTROL_PORT, MODE_PSGVOL); // Select PSG volume register
+        tmp_uint8 = inp(DATA_PORT_HIGH);
+        outp(CONTROL_PORT, MODE_MAINVOL); // Select Main volume register
+        tmp_uint16 = inp(DATA_PORT_HIGH);
+        printf("Volume:     PSG: %u     Main: %u\n", tmp_uint8, tmp_uint16);
         break;
     case SB_MODE:
         if (init_sb()) {
@@ -967,9 +1058,22 @@ int main(int argc, char* argv[]) {
             outp(CONTROL_PORT, MODE_OPLWAIT); // Select Adlib wait register
             tmp_uint8 = inp(DATA_PORT_HIGH);
             printf("%s)\n", tmp_uint8 ? ", wait on" : "");
+            outp(CONTROL_PORT, MODE_OPLVOL); // Select Adlib volume register
+            tmp_uint8 = inp(DATA_PORT_HIGH);
+            printf("Volume:     ");
+            printf("OPL: %u    ", tmp_uint8);
         } else {
             printf("(AdLib port disabled)\n");
+            printf("Volume:     ");
         }
+        outp(CONTROL_PORT, MODE_SBVOL); // Select Sound Blaster volume register
+        uint8_t tmp_uint8 = inp(DATA_PORT_HIGH);
+        printf("SB: %u    ", tmp_uint8);
+
+        outp(CONTROL_PORT, MODE_MAINVOL); // Select Sound Blaster volume register
+        tmp_uint8 = inp(DATA_PORT_HIGH);
+        printf("Main: %u    \n", tmp_uint8);
+
         print_cdemu_status();
         break;
     case NE2000_MODE:

sw/CMakeLists.txt

@@ -204,6 +204,7 @@ function(build_gus TARGET_NAME MULTIFW)
     config_target(${TARGET_NAME} ${MULTIFW})
     pico_set_program_name(${TARGET_NAME} "picogus-gus")
     target_sources(${TARGET_NAME} PRIVATE
+        volctrl.cpp
         gusplay.cpp
         isa_dma.c
     )
@@ -241,6 +242,7 @@ function(build_sb TARGET_NAME MULTIFW)
     config_target(${TARGET_NAME} ${MULTIFW})
     pico_set_program_name(${TARGET_NAME} "picogus-sb")
     target_sources(${TARGET_NAME} PRIVATE
+        volctrl.cpp
         sbdsp.cpp
         sbplay.cpp
         isa_dma.c
@@ -263,7 +265,10 @@ function(build_adlib TARGET_NAME MULTIFW)
     set(SOUND_OPL TRUE)
     config_target(${TARGET_NAME} ${MULTIFW})
     pico_set_program_name(${TARGET_NAME} "picogus-adlib")
-    target_sources(${TARGET_NAME} PRIVATE sbplay.cpp)    
+    target_sources(${TARGET_NAME} PRIVATE 
+        volctrl.cpp
+        sbplay.cpp
+    )    
 endfunction()
 
 ################################################################################
@@ -295,6 +300,7 @@ function(build_psg TARGET_NAME MULTIFW)
         SOUND_CMS=1
     )
     target_sources(${TARGET_NAME} PRIVATE
+        volctrl.cpp
         square/square.cpp
     )
     target_sources(${TARGET_NAME} PRIVATE psgplay.cpp)
@@ -312,7 +318,10 @@ function(build_usb TARGET_NAME MULTIFW)
     target_compile_definitions(${TARGET_NAME} PRIVATE
         USB_ONLY=1
     )
-    target_sources(${TARGET_NAME} PRIVATE usbplay.cpp)
+    target_sources(${TARGET_NAME} PRIVATE 
+        volctrl.cpp
+        usbplay.cpp
+    )
 endfunction()
 
 

sw/cdrom/cdrom.c

@@ -32,6 +32,7 @@
 #include "cdrom_error_msg.h"
 #include "pico/multicore.h"
 #include "hardware/structs/timer.h"
+#include "../volctrl.h"
 
 
 /* The addresses sent from the guest are absolute, ie. a LBA of 0 corresponds to a MSF of 00:00:00. Otherwise, the counter displayed by the guest is wrong:
@@ -399,7 +400,14 @@ uint32_t cdrom_audio_callback_simple(cdrom_t *dev, int16_t *buffer, uint32_t len
 
         /* printf("%u\n", samples_to_transfer); */
         // Add samples from sector buffer to FIFO
-        memcpy(buffer + samples_produced, &dev->current_sector_samples[dev->audio_sector_consumed_samples], samples_to_transfer * sizeof(int16_t));
+        //memcpy(buffer + samples_produced, &dev->current_sector_samples[dev->audio_sector_consumed_samples], samples_to_transfer * sizeof(int16_t));
+
+        for (uint32_t i = 0; i < samples_to_transfer; i++)
+        {
+            int32_t sample = dev->current_sector_samples[dev->audio_sector_consumed_samples + i];       
+            buffer[samples_produced + i] = (int16_t)scale_sample(sample, cd_audio_volume, 0);
+        }
+
         samples_produced += samples_to_transfer;
         dev->audio_sector_consumed_samples += samples_to_transfer;
     } // End while (fifo_level < len && ret)

sw/cdrom/cdrom.h

@@ -15,6 +15,7 @@
  *          Copyright 2016-2019 Miran Grca.
  *          Copyright (C) 2024 Kevin Moonlight
  *          Copyright (C) 2025 Ian Scott
+ *          Copyright (C) 2025 Daniel Arnold
  */
 
 #ifndef EMU_CDROM_H
@@ -61,7 +62,6 @@
 #define STAT_DISK	    0x40
 #define STAT_TRAY	    0x80
 
-
 /* This is so that if/when this is changed to something else,
    changing this one define will be enough. */
 #define CDROM_EMPTY !dev->host_drive
@@ -201,6 +201,7 @@ typedef struct cdrom {
     int16_t *current_sector_samples;       // Convenience pointer: (int16_t*)audio_sector_buffer
     int audio_sector_total_samples;        // Samples available in current_sector_samples after a read
     int audio_sector_consumed_samples;     // Samples consumed from current_sector_samples
+
 #if USE_CD_AUDIO_FIFO
     audio_fifo_t audio_fifo;
 #endif
@@ -272,6 +273,9 @@ extern int find_cdrom_for_scsi_id(uint8_t scsi_id);
 extern void cdrom_close(void);
 extern void cdrom_global_init(void);
 
+extern int32_t cd_audio_volume; 
+extern void cdrom_set_volume_scale(uint8_t percent);
+
 #ifdef __cplusplus
 }
 #endif

sw/flash_settings.c

@@ -77,6 +77,14 @@ static const Settings defaultSettings = {
     .MMB = {
         // Mindscape Music Board defaults to off because its port is so common
         .basePort = 0xffff
+    },
+    .Volume = {
+        .mainVol = 100,
+        .oplVol = 90,
+        .sbVol = 100,
+        .cdVol = 100,
+        .gusVol = 100,
+        .psgVol = 80
     }
 };
 

sw/flash_settings.h

@@ -80,6 +80,14 @@ typedef struct Settings {
     struct {
         uint16_t basePort;
     } MMB;
+    struct {
+        uint8_t mainVol;
+        uint8_t oplVol;
+        uint8_t sbVol;
+        uint8_t cdVol;
+        uint8_t gusVol;
+        uint8_t psgVol;
+    } Volume;
 } Settings;
 
 

sw/gus-x.cpp

@@ -43,6 +43,7 @@ critical_section_t gus_crit;
 extern dma_inst_t dma_config;
 
 #include "clamp.h"
+#include "volctrl.h"
 
 using namespace std;
 
@@ -615,6 +616,7 @@ class GUSChannels {
 
             // Output stereo sample if DAC enable on
             // if ((GUS_reset_reg & 0x02/*DAC enable*/) == 0x02) {
+                tmpsamp = scale_sample(tmpsamp, gus_volume, 0);
                 stream[0] += tmpsamp * VolLeft;
                 stream[1] += tmpsamp * VolRight;
                 WaveUpdate();

sw/picogus.cpp

@@ -58,6 +58,8 @@ uint LED_PIN;
 #include "M62429/M62429.h"
 M62429* m62429;
 
+
+
 #ifdef SOUND_SB
 static uint16_t sb_port_test;
 extern void sbdsp_write(uint8_t address, uint8_t value);
@@ -89,7 +91,6 @@ static uint32_t cur_read_idx;
 
 #ifdef SOUND_GUS
 #include "gus-x.cpp"
-
 #include "isa_dma.h"
 dma_inst_t dma_config;
 static uint16_t gus_port_test;
@@ -140,6 +141,10 @@ uint8_t joystate_bin;
 void play_usb(void);
 #endif
 
+#if SOUND_GUS || SOUND_SB || SOUND_OPL || CDROM || SOUND_TANDY || SOUND_CMS
+#include "volctrl.h"
+#endif
+
 
 // PicoGUS control and data ports
 static bool control_active = false;
@@ -232,6 +237,12 @@ __force_inline void select_picogus(uint8_t value) {
     case MODE_CDSTATUS:
     case MODE_CDLOAD:
     case MODE_CDAUTOADV:
+    case MODE_MAINVOL:
+    case MODE_OPLVOL:
+    case MODE_SBVOL:
+    case MODE_CDVOL:
+    case MODE_GUSVOL:
+    case MODE_PSGVOL:
         break;
     case MODE_CDNAME:
         cur_write = 0;
@@ -412,6 +423,45 @@ __force_inline void write_picogus_high(uint8_t value) {
         cdman_set_autoadvance(settings.CD.autoAdvance);
 #endif
         break;
+
+    case MODE_MAINVOL: // Set the volume for CD Audio
+        settings.Volume.mainVol = value;
+
+#if SOUND_GUS || SOUND_SB || SOUND_OPL || CDROM || SOUND_TANDY || SOUND_CMS
+        set_volume(MODE_MAINVOL);
+#endif
+        break;
+    case MODE_OPLVOL: // Set the volume for Adlib
+        settings.Volume.oplVol = value;
+#ifdef SOUND_SB
+        set_volume(MODE_OPLVOL);
+#endif
+        break;
+    case MODE_SBVOL: // Set the volume for Sound Blaster
+        settings.Volume.sbVol = value;
+#ifdef SOUND_SB
+        set_volume(MODE_SBVOL);
+#endif
+        break;
+        case MODE_CDVOL: // Set the volume for CD Audio
+        settings.Volume.cdVol = value;
+#ifdef CDROM
+        set_volume(MODE_CDVOL);
+#endif
+        break;
+        case MODE_GUSVOL: // Set the volume for GUS
+        settings.Volume.gusVol = value;
+#ifdef SOUND_GUS
+        set_volume(MODE_GUSVOL);
+#endif
+        break;
+        case MODE_PSGVOL: // Set the volume for PSG
+        settings.Volume.psgVol = value;
+#if SOUND_PSG || SOUND_TANDY || SOUND_CMS
+        set_volume(MODE_PSGVOL);
+#endif
+        break;
+
     // For multifw
     case MODE_BOOTMODE:
         settings.startupMode = value;
@@ -565,6 +615,18 @@ __force_inline uint8_t read_picogus_high(void) {
 #endif
     case MODE_CDAUTOADV: // enable joystick
         return settings.CD.autoAdvance;
+    case MODE_MAINVOL: // CD audio volume
+        return settings.Volume.mainVol;
+    case MODE_OPLVOL: // Adlib volume
+        return settings.Volume.oplVol;
+    case MODE_SBVOL: // Sound Blaster volume
+        return settings.Volume.sbVol;
+    case MODE_CDVOL: // CD audio volume
+        return settings.Volume.cdVol;
+    case MODE_GUSVOL: // GUS volume
+        return settings.Volume.gusVol;
+    case MODE_PSGVOL: // PSG volume
+        return settings.Volume.psgVol;
     case MODE_HWTYPE: // Hardware version
         return BOARD_TYPE;
     case MODE_FLASH:
@@ -579,12 +641,16 @@ __force_inline uint8_t read_picogus_high(void) {
 void processSettings(void) {
 #if defined(SOUND_GUS)
     settings.startupMode = GUS_MODE;
+    set_volume(MODE_GUSVOL);
 #elif (SOUND_TANDY || SOUND_CMS)
     settings.startupMode = PSG_MODE;
+    set_volume(MODE_PSGVOL);
 #elif defined(SOUND_SB)
     settings.startupMode = SB_MODE;
+    set_volume(MODE_SBVOL);
 #elif defined(SOUND_OPL)
     settings.startupMode = ADLIB_MODE;
+    set_volume(MODE_OPLVOL);
 #elif defined(MPU_ONLY)
     settings.startupMode = MPU_MODE;
 #elif defined(USB_ONLY)

sw/psgplay.cpp

@@ -32,6 +32,7 @@
 #include "square/square.h"
 
 #include "cmd_buffers.h"
+#include "volctrl.h"
 
 #if SOUND_TANDY
 extern tandy_buffer_t tandy_buffer;
@@ -170,9 +171,9 @@ void play_psg() {
         cms.generator(0).generate_frames(buf, SAMPLES_PER_BUFFER);
         cms.generator(1).generate_frames(buf, SAMPLES_PER_BUFFER);
 #endif
-        for (int i = 0; i < SAMPLES_PER_BUFFER; ++i) {
-            samples[i << 1] = buf[i << 1] >> 1;
-            samples[(i << 1) + 1] = buf[(i << 1) + 1] >> 1;
+        for (int i = 0; i < SAMPLES_PER_BUFFER; ++i) {          
+            samples[i << 1] = scale_sample(buf[i << 1], psg_volume, 0);
+            samples[(i << 1) + 1] = scale_sample(buf[(i << 1) + 1], psg_volume, 0);
         }
         buffer->sample_count = SAMPLES_PER_BUFFER;
 

sw/sbplay.cpp

@@ -28,6 +28,7 @@
 
 #include "pico/stdlib.h"
 #include "pico/audio_i2s.h"
+#include "volctrl.h"
 
 #include "opl.h"
 extern "C" void OPL_Pico_simple(int16_t *buffer, uint32_t nsamples);
@@ -121,6 +122,7 @@ struct audio_buffer_pool *init_audio() {
     ok = audio_i2s_connect_extra(producer_pool, false, 0, 0, NULL);
     assert(ok);
     audio_i2s_set_enabled(true);
+
     return producer_pool;
 }
 
@@ -140,7 +142,6 @@ static inline int16_t lerp_fixed(int16_t v0, int16_t v1, uint32_t frac) {
     return v0 + (int16_t)(((int32_t)(v1 - v0) * frac) >> FRAC_BITS);
 }
 
-
 void play_adlib() {
     puts("starting core 1");
     // flash_safe_execute_core_init();
@@ -244,9 +245,13 @@ void play_adlib() {
             int32_t opl_sample = lerp_fixed(
                 opl_samples[opl_index & OPL_BUFFER_BITS],
                 opl_samples[(opl_index + 1) & OPL_BUFFER_BITS],
-                opl_frac);
+                opl_frac);            
+           
+            opl_sample = scale_sample(opl_sample << 2, opl_volume, 1);
+
             accum[0] += opl_sample;
             accum[1] += opl_sample;
+
 #if SOUND_SB
             if (!sb_left) {
                 // putchar('t');
@@ -260,11 +265,26 @@ void play_adlib() {
                 }
                 sb_index_old = sb_index;
                 sb_frac = sb_pos & FRAC_MASK;
-                sb_ratio = fixed_ratio(sbdsp_sample_rate(), 44100);
+                //sb_ratio = fixed_ratio(sbdsp_sample_rate(), 44100);
+
+                static uint16_t last_sb_rate = 0;
+                uint16_t current_rate = sbdsp_sample_rate();
+                if (current_rate != last_sb_rate)
+                {
+                    sb_ratio = fixed_ratio(current_rate, 44100);
+                    last_sb_rate = current_rate;
+                }
+
                 sb_pos += sb_ratio;
                 // putchar('p');
                 if (!sbdsp_muted()) {
-                    int16_t sb_sample = sb_fifo->buffer[sb_index & AUDIO_FIFO_BITS];
+                    //int16_t sb_sample = sb_fifo->buffer[sb_index & AUDIO_FIFO_BITS];
+
+                    int16_t *fifo_buf = sb_fifo->buffer;
+                    int16_t sb_sample = fifo_buf[sb_index & AUDIO_FIFO_BITS];
+                    
+                    sb_sample = scale_sample((int32_t)sb_sample >> 1, sb_volume, 1);
+
                     accum[0] += sb_sample;
                     accum[1] += sb_sample;
                 }

sw/volctrl.cpp

@@ -0,0 +1,85 @@
+/*
+ *  Copyright (C) 2025  Daniel Arnold
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program 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 General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; 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 "flash_settings.h"
+#include "pico/stdlib.h"
+#include "volctrl.h"
+#include "clamp.h"
+#include "flash_settings.h"
+extern Settings settings;
+
+int32_t opl_volume = 0x10000; // default 1.0x volume
+int32_t sb_volume = 0x10000; // default 1.0x volume
+int32_t cd_audio_volume = 0x10000; // default 1.0x volume
+int32_t gus_volume = 0x10000; // default 1.0x volume
+int32_t psg_volume = 0x10000; // default 1.0x volume
+
+
+int32_t set_volume_scale (uint8_t percent) {
+     if (percent > 100)
+        percent = 100;
+
+    uint8_t delta = 100 - settings.Volume.mainVol;
+
+    int32_t volume = ((percent - delta) * 65536) / 100;
+    
+    if (percent < 1) 
+        volume = 0;
+
+    return volume;
+}
+
+int32_t scale_sample (int32_t sample, int32_t scale, int clamp) {
+    sample = (sample * scale) >> 16;
+
+    if (clamp)
+        clamp16(sample);
+
+    return sample;
+}
+
+void set_volume(uint16_t mode) {
+
+    switch (mode){
+        case MODE_MAINVOL:
+            set_volume(MODE_OPLVOL);
+            set_volume(MODE_SBVOL);
+            set_volume(MODE_CDVOL);
+            set_volume(MODE_GUSVOL);
+            set_volume(MODE_PSGVOL);
+            break;
+        case MODE_OPLVOL:
+            opl_volume = set_volume_scale(settings.Volume.oplVol);
+            break;
+        case MODE_SBVOL:
+            sb_volume = set_volume_scale(settings.Volume.sbVol);
+            break;
+        case MODE_CDVOL:
+            cd_audio_volume = set_volume_scale(settings.Volume.sbVol);
+            break;
+        case MODE_GUSVOL:
+            gus_volume = set_volume_scale(settings.Volume.gusVol);
+            break;
+        case MODE_PSGVOL:
+            psg_volume = set_volume_scale(settings.Volume.psgVol);
+            break;
+    }   
+}

sw/volctrl.h

@@ -0,0 +1,43 @@
+/*
+ *  Copyright (C) 2025  Daniel Arnold
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program 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 General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+#pragma once
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdint.h>
+#include <stdbool.h>
+#include "../common/picogus.h"
+#include "flash_settings.h"
+
+extern int32_t opl_volume;
+extern int32_t sb_volume;
+extern int32_t cd_audio_volume;
+extern int32_t gus_volume;
+extern int32_t psg_volume;
+
+
+extern int32_t set_volume_scale (uint8_t percent);
+extern int32_t scale_sample (int32_t sample, int32_t scale, int clamp);
+
+void set_volume(uint16_t mode);
+
+#ifdef __cplusplus
+}
+#endif