Fix speed settings initialization and add config file documentation

- Fix speed toggle not reading saved turboMode setting from QSettings
- Speed toggle now properly reflects saved state instead of defaulting to false
- Ensures correct defaults: 1x speed with turbo mode unchecked
- Improve Windows/Linux audio stability with larger buffers
- Add Configuration Files section to README documenting storage locations
  for all platforms (macOS, Windows, Linux)

Author: pedgarcia

README.md

@@ -394,6 +394,50 @@ fujisan.exe
 ### Known Limitations
 - **Printer Support**: P: device (printer) functionality is currently disabled due to Error 138 (Device Timeout) issues in the atari800 core. Commands like `LPRINT` and `LIST "P:"` will not work. This limitation also affects the official atari800 emulator and is not specific to Fujisan.
 
+## Configuration Files
+
+Fujisan stores its configuration in platform-specific locations following standard OS conventions.
+
+### Main Settings
+
+Application settings (speed, audio, video, etc.) are stored using Qt's native settings format:
+
+**macOS:**
+```
+~/Library/Preferences/com.8bitrelics.Fujisan.plist
+```
+
+**Windows:**
+```
+Registry: HKEY_CURRENT_USER\Software\8bitrelics\Fujisan
+```
+
+**Linux:**
+```
+~/.config/8bitrelics/Fujisan.conf
+```
+
+### Configuration Profiles
+
+Machine configuration profiles (complete emulator setups) are stored as JSON files:
+
+**macOS:**
+```
+~/Library/Application Support/Fujisan/profiles/*.profile
+```
+
+**Windows:**
+```
+C:\Users\<username>\AppData\Roaming\Fujisan\profiles\*.profile
+```
+
+**Linux:**
+```
+~/.local/share/Fujisan/profiles/*.profile
+```
+
+Profiles contain complete machine configurations including hardware settings, memory configuration, peripherals, and media paths. They can be managed through the Settings dialog's profile system.
+
 ## TCP Server API
 
 Fujisan includes a powerful TCP server for remote control and automation. This enables IDE integration, automated testing, and programmatic control of all emulator features.

src/atariemulator.cpp

@@ -953,8 +953,9 @@ void AtariEmulator::processFrame()
                 gap += m_dspBufferBytes;
             }
 
-            // Conditional speed adjustment - disabled for Windows due to Qt audio issues
-#ifndef _WIN32
+            // Conditional speed adjustment - disabled for Windows/Linux due to Qt audio issues
+            // Speed micro-adjustments can cause timing variations during typing/UI operations
+#if 0  // Disabled for all platforms - provides more stable audio
             updateEmulationSpeed();
 #endif
 
@@ -1760,7 +1761,7 @@ void AtariEmulator::setupAudio()
 #if defined(_WIN32) || defined(__linux__)
     // Windows/Linux: Use larger fragments for stability with dynamic frame timing
     m_fragmentSize = 1024; // Larger fragments for better Qt audio stability (~23ms at 44100Hz)
-    int targetDelayMs = 30;   // Slight headroom for UI operations (drag/resize/typing)
+    int targetDelayMs = 50;   // Extra headroom for UI operations and typing resilience
 #else
     // macOS: Smaller buffers work fine here
     m_fragmentSize = 512; // Smaller fragments for more responsive audio
@@ -1775,7 +1776,7 @@ void AtariEmulator::setupAudio()
     m_targetDelay = (m_sampleRate * targetDelayMs) / 1000;  // Convert to samples
     // Use a larger buffer to handle the accumulation
 #if defined(_WIN32) || defined(__linux__)
-    int dspBufferSamples = m_fragmentSize * 20;  // Large buffer for Windows/Linux to handle frame timing variations
+    int dspBufferSamples = m_fragmentSize * 25;  // Extra-large buffer for maximum stability during typing/UI ops
 #else
     int dspBufferSamples = m_fragmentSize * 10;  // Standard buffer for macOS
 #endif
@@ -1818,11 +1819,11 @@ void AtariEmulator::setupAudio()
     m_audioOutput->setNotifyInterval(notifyMs);
 
     // Set category for optimal performance
-#ifdef _WIN32
-    // Windows: Use music category for higher latency/buffering
+#if defined(_WIN32) || defined(__linux__)
+    // Windows/Linux: Use music category for higher latency/buffering and stability
     m_audioOutput->setCategory("music");
 #else
-    // macOS/Linux: Use game category for lower latency
+    // macOS: Use game category for lower latency (works fine with smaller buffers)
     m_audioOutput->setCategory("game");
 #endif
 

src/mainwindow.cpp

@@ -1089,9 +1089,11 @@ void MainWindow::updateToolbarFromSettings()
     m_videoToggle->blockSignals(false);
 
 
-    // Update speed toggle (default to normal speed)
+    // Update speed toggle from settings
+    QSettings speedSettings("8bitrelics", "Fujisan");
+    bool turboMode = speedSettings.value("machine/turboMode", false).toBool();
     m_speedToggle->blockSignals(true);
-    m_speedToggle->setChecked(false); // Default to normal speed (100%)
+    m_speedToggle->setChecked(turboMode);
     m_speedToggle->blockSignals(false);
 
     // Update menu actions