@@ -1,8 +1,14 @@ 
 CC = gcc
 CFLAGS = -Wall -Wextra -g
 
-SOURCES = xyw.c xywasm.c xywrun.c devices/system.c devices/terminal.c devices/clock.c devices/file.c
-OBJS = xyw.o xywasm.o xywrun.o devices/system.o devices/terminal.o devices/clock.o devices/file.o
+SOURCES = xyw.c xywasm.c xywrun.c devices/system.c devices/terminal.c devices/clock.c devices/file.c devices/beeper.c
+OBJS = xyw.o xywasm.o xywrun.o devices/system.o devices/terminal.o devices/clock.o devices/file.o devices/beeper.o
+
+# Platform-specific linker flags
+UNAME_S := $(shell uname -s 2>/dev/null || echo Windows)
+ifeq ($(UNAME_S),Darwin)
+	LDFLAGS += -framework AudioToolbox
+endif
 
 .PHONY: clean
 
@@ -29,6 +35,9 @@ $(CC) $(CFLAGS) -c devices/clock.c -o devices/clock.o
 
 devices/file.o: devices/file.c xyw.h
 	$(CC) $(CFLAGS) -c devices/file.c -o devices/file.o
+
+devices/beeper.o: devices/beeper.c xyw.h
+	$(CC) $(CFLAGS) -c devices/beeper.c -o devices/beeper.o
 
 clean:
 	rm -f xyw xyw.exe $(OBJS)

@@ -0,0 +1,214 @@ 
+#include <stdio.h>
+#ifdef _WIN32
+#include <windows.h>
+#elif defined(__APPLE__)
+#include <AudioToolbox/AudioToolbox.h>
+#include <unistd.h>
+#include <math.h>
+#elif defined(__linux__)
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <linux/kd.h>
+#else /* Other Unix (BSD, etc.) */
+#include <unistd.h>
+#endif
+#include "../xyw.h"
+
+/* beeper device */
+#define BEEPER_PITCH 0x0
+#define BEEPER_LENGTH 0x2
+#define BEEPER_LEVEL 0x4
+
+#define BEEPER_MAX_FREQ 0x2000 /* 8192 Hz */
+#define BEEPER_MAX_LEVEL 0x0F
+
+#ifdef __APPLE__
+/* macOS: Generate sine wave tone using AudioQueue */
+#define APPLE_SAMPLE_RATE 44100.0
+#define APPLE_NUM_BUFFERS 3
+
+typedef struct
+{
+    AudioQueueRef queue;
+    double phase;
+    double phase_increment;
+    float amplitude;
+    UInt32 samples_remaining;
+    int finished;
+} AppleToneState;
+
+static void apple_audio_callback(void *user_data, AudioQueueRef queue, AudioQueueBufferRef buffer)
+{
+    AppleToneState *state = (AppleToneState *)user_data;
+    SInt16 *samples = (SInt16 *)buffer->mAudioData;
+    UInt32 num_samples = buffer->mAudioDataByteSize / sizeof(SInt16);
+
+    if (state->samples_remaining == 0)
+    {
+        /* Fill with silence and mark finished */
+        for (UInt32 i = 0; i < num_samples; i++)
+            samples[i] = 0;
+        state->finished = 1;
+    }
+    else
+    {
+        UInt32 to_generate = num_samples < state->samples_remaining ? num_samples : state->samples_remaining;
+        for (UInt32 i = 0; i < to_generate; i++)
+        {
+            samples[i] = (SInt16)(sin(state->phase) * 32767.0 * state->amplitude);
+            state->phase += state->phase_increment;
+            if (state->phase > 2.0 * M_PI)
+                state->phase -= 2.0 * M_PI;
+        }
+        for (UInt32 i = to_generate; i < num_samples; i++)
+            samples[i] = 0;
+        state->samples_remaining -= to_generate;
+    }
+    AudioQueueEnqueueBuffer(queue, buffer, 0, NULL);
+}
+
+static void apple_play_tone(xyw_word freq, unsigned long duration_ms, xyw_byte level)
+{
+    AppleToneState state = {0};
+    AudioStreamBasicDescription format = {0};
+    AudioQueueBufferRef buffers[APPLE_NUM_BUFFERS];
+
+    format.mSampleRate = APPLE_SAMPLE_RATE;
+    format.mFormatID = kAudioFormatLinearPCM;
+    format.mFormatFlags = kLinearPCMFormatFlagIsSignedInteger | kLinearPCMFormatFlagIsPacked;
+    format.mBitsPerChannel = 16;
+    format.mChannelsPerFrame = 1;
+    format.mBytesPerFrame = 2;
+    format.mFramesPerPacket = 1;
+    format.mBytesPerPacket = 2;
+
+    state.phase = 0.0;
+    state.phase_increment = 2.0 * M_PI * freq / APPLE_SAMPLE_RATE;
+    state.amplitude = (float)level / (float)BEEPER_MAX_LEVEL;
+    state.samples_remaining = (UInt32)(APPLE_SAMPLE_RATE * duration_ms / 1000.0);
+    state.finished = 0;
+
+    if (AudioQueueNewOutput(&format, apple_audio_callback, &state, NULL, NULL, 0, &state.queue) != noErr)
+        return;
+
+    UInt32 buffer_size = 4096;
+    for (int i = 0; i < APPLE_NUM_BUFFERS; i++)
+    {
+        AudioQueueAllocateBuffer(state.queue, buffer_size, &buffers[i]);
+        buffers[i]->mAudioDataByteSize = buffer_size;
+        apple_audio_callback(&state, state.queue, buffers[i]);
+    }
+
+    AudioQueueStart(state.queue, NULL);
+
+    /* Wait for playback to complete */
+    while (!state.finished)
+        usleep(10000);
+    usleep(50000); /* Small delay for buffer drain */
+
+    AudioQueueStop(state.queue, true);
+    AudioQueueDispose(state.queue, true);
+}
+#endif /* __APPLE__ */
+
+#if defined(__linux__)
+/* Linux: Use KIOCSOUND ioctl for PC speaker frequency control */
+#define CLOCK_TICK_RATE 1193180
+
+static void linux_play_tone(xyw_word freq, unsigned long duration_ms)
+{
+    int fd = open("/dev/console", O_WRONLY);
+    if (fd < 0)
+        fd = open("/dev/tty0", O_WRONLY);
+
+    if (fd >= 0 && freq > 0)
+    {
+        /* Set frequency: KIOCSOUND takes clock_tick_rate / frequency, or 0 to stop */
+        unsigned int period = CLOCK_TICK_RATE / freq;
+        ioctl(fd, KIOCSOUND, period);
+        usleep((useconds_t)duration_ms * 1000);
+        ioctl(fd, KIOCSOUND, 0); /* Stop */
+        close(fd);
+    }
+    else
+    {
+        /* Fallback: BEL character (no frequency control) */
+        if (fd >= 0)
+            close(fd);
+        fputc('\a', stdout);
+        fflush(stdout);
+        usleep((useconds_t)duration_ms * 1000);
+    }
+}
+#endif /* __linux__ */
+
+void beeper_output(xyw_byte *data, xyw_byte addr, xyw_byte *error)
+{
+    (void)error;
+
+    switch (addr)
+    {
+    case BEEPER_PITCH:
+    case BEEPER_PITCH + 1:
+    case BEEPER_LENGTH:
+    case BEEPER_LENGTH + 1:
+        /* Just store the value, beep triggers on level write */
+        break;
+
+    case BEEPER_LEVEL:
+    {
+        /* Get pitch (2 bytes, big-endian) */
+        xyw_word pitch = XYW_PEEKW(&data[BEEPER_PITCH]);
+
+        /* Get length in 1/256 second units (2 bytes, big-endian) */
+        xyw_word length = XYW_PEEKW(&data[BEEPER_LENGTH]);
+
+        /* Get volume level (0-15) */
+        xyw_byte level = data[BEEPER_LEVEL];
+
+        /* Clamp values */
+        if (pitch > BEEPER_MAX_FREQ)
+            pitch = BEEPER_MAX_FREQ;
+        if (level > BEEPER_MAX_LEVEL)
+            level = BEEPER_MAX_LEVEL;
+
+        /* Only beep if level > 0 and pitch > 0 and length > 0 */
+        if (level > 0 && pitch > 0 && length > 0)
+        {
+            /* Convert length from 1/256 seconds to milliseconds */
+            /* 1/256 second = 1000/256 ms ≈ 3.90625 ms */
+            unsigned long duration_ms = ((unsigned long)length * 1000) / 256;
+            if (duration_ms == 0)
+                duration_ms = 1;
+
+#ifdef _WIN32
+            /* Windows Beep() function - ignores volume level */
+            (void)level;
+            Beep((DWORD)pitch, (DWORD)duration_ms);
+#elif defined(__APPLE__)
+            /* macOS: Generate sine wave via AudioQueue */
+            apple_play_tone(pitch, duration_ms, level);
+#elif defined(__linux__)
+            /* Linux: Use PC speaker via KIOCSOUND ioctl (ignores volume) */
+            (void)level;
+            linux_play_tone(pitch, duration_ms);
+#else
+            /* Other Unix: BEL fallback (no frequency control) */
+            (void)pitch;
+            (void)level;
+            fputc('\a', stdout);
+            fflush(stdout);
+            usleep((useconds_t)duration_ms * 1000);
+#endif
+        }
+        break;
+    }
+    }
+}
+
+xyw_byte beeper_input(xyw_byte *data, xyw_byte addr, xyw_byte *error)
+{
+    (void)error;
+    return data[addr];
+}

@@ -0,0 +1,4 @@ 
+#include "../xyw.h"
+
+void beeper_output(xyw_byte *data, xyw_byte addr, xyw_byte *error);
+xyw_byte beeper_input(xyw_byte *data, xyw_byte addr, xyw_byte *error);

@@ -0,0 +1,8 @@ 
+.include "lib/macros.xyw"
+
+$0400 beeper.pitch STW
+$0080 beeper.length STW
+$04 beeper.level STB
+$0800 beeper.pitch STW
+$0080 beeper.length STW
+$04 beeper.level STB

@@ -37,10 +37,9 @@ .macro file.write             $3B
 .macro file.operation         $3D
 
 ;beeper
-.macro beeper.state           $40
-.macro beeper.samples         $41
-.macro beeper.n_samples       $43
-.macro beeper.on_stop         $45
+.macro beeper.pitch           $40
+.macro beeper.length          $42
+.macro beeper.level           $44
 
 ;;; Utilities
 .macro MOD DIV POP

@@ -6,6 +6,7 @@ #include "devices/system.h"
 #include "devices/terminal.h"
 #include "devices/clock.h"
 #include "devices/file.h"
+#include "devices/beeper.h"
 
 #define MEMORY_SIZE 0xffff
 #define STACK_SIZE 0xff
@@ -295,6 +296,8 @@ // Clock device
     {&xyw_memory[0xff20], clock_init, clock_input, clock_output},
     // File device
     {&xyw_memory[0xff30], file_init, file_input, file_output},
+    // Beeper device
+    {&xyw_memory[0xff40], 0, beeper_input, beeper_output},
     // ...
 };
 // clang-format on