diff --git a/src/LibHac/FsSrv/AccessLogService.cs b/src/LibHac/FsSrv/AccessLogService.cs
index e81e3018..5bd6dbe3 100644
--- a/src/LibHac/FsSrv/AccessLogService.cs
+++ b/src/LibHac/FsSrv/AccessLogService.cs
@@ -1,15 +1,34 @@
 using System;
+using LibHac.Common;
 using LibHac.Fs;
 using LibHac.FsSrv.Impl;
 using LibHac.Sf;
+using static LibHac.FsSrv.Anonymous;
 
 namespace LibHac.FsSrv;
 
+file static class Anonymous
+{
+    public static Result GetProgramInfo(FileSystemServer fsServer, out ProgramInfo programInfo, ulong processId)
+    {
+        var programRegistry = new ProgramRegistryImpl(fsServer);
+        return programRegistry.GetProgramInfo(out programInfo, processId).Ret();
+    }
+}
+
+/// <summary>
+/// Handles access log calls for <see cref="FileSystemProxyImpl"/>.
+/// </summary>
+/// <remarks><para>This struct handles checking a process' permissions before forwarding
+/// requests to the <see cref="AccessLogServiceImpl"/> object.</para>
+/// <para>Based on nnSdk 18.3.0 (FS 18.0.0)</para></remarks>
 internal readonly struct AccessLogService
 {
     private readonly AccessLogServiceImpl _serviceImpl;
     private readonly ulong _processId;
 
+    private FileSystemServer FsServer => _serviceImpl.FsServer;
+
     public AccessLogService(AccessLogServiceImpl serviceImpl, ulong processId)
     {
         _serviceImpl = serviceImpl;
@@ -18,7 +37,7 @@ internal readonly struct AccessLogService
 
     public Result SetAccessLogMode(GlobalAccessLogMode mode)
     {
-        Result res = GetProgramInfo(out ProgramInfo programInfo);
+        Result res = GetProgramInfo(FsServer, out ProgramInfo programInfo, _processId);
         if (res.IsFailure()) return res.Miss();
 
         if (!programInfo.AccessControl.CanCall(OperationType.SetGlobalAccessLogMode))
@@ -36,15 +55,46 @@ internal readonly struct AccessLogService
 
     public Result OutputAccessLogToSdCard(InBuffer textBuffer)
     {
-        Result res = GetProgramInfo(out ProgramInfo programInfo);
+        Result res = GetProgramInfo(FsServer, out ProgramInfo programInfo, _processId);
         if (res.IsFailure()) return res.Miss();
 
-        return _serviceImpl.OutputAccessLogToSdCard(textBuffer.Buffer, programInfo.ProgramIdValue, _processId);
+        return _serviceImpl.OutputAccessLogToSdCard(textBuffer.Buffer, programInfo.ProgramIdValue, _processId).Ret();
     }
 
+    private static ReadOnlySpan<byte> OutputAccessLog => "FS_ACCESS: { multi_program_tag: true }\n"u8;
+    private static ReadOnlySpan<byte> OutputLogTagUnknown => "FS_ACCESS: { application_info_tag: { launch_type: Unknown } }\n"u8;
+    private static ReadOnlySpan<byte> OutputHead => "FS_ACCESS: { application_info_tag: { launch_type: "u8;
+    private static ReadOnlySpan<byte> OutputApplicationId => "Application, application_id: 0x"u8;
+    private static ReadOnlySpan<byte> OutputPatchId => "Patch, application_id: 0x"u8;
+    private static ReadOnlySpan<byte> OutputVersion => ", release_version: 0x"u8;
+    private static ReadOnlySpan<byte> OutputTail => " } }\n"u8;
+
     public Result OutputApplicationInfoAccessLog(in ApplicationInfo applicationInfo)
     {
-        throw new NotImplementedException();
+        if (applicationInfo.IsMultiProgram)
+        {
+            _serviceImpl.OutputAccessLogToSdCard(OutputAccessLog, applicationInfo.ApplicationId.Value, _processId).IgnoreResult();
+        }
+
+        if (applicationInfo.LaunchType == 0)
+        {
+            _serviceImpl.OutputAccessLogToSdCard(OutputLogTagUnknown, applicationInfo.ApplicationId.Value, _processId).IgnoreResult();
+        }
+        else
+        {
+            Span<byte> buffer = stackalloc byte[0x80];
+            ReadOnlySpan<byte> outputId = applicationInfo.LaunchType == 1 ? OutputApplicationId : OutputPatchId;
+
+            var sb = new U8StringBuilder(buffer, autoExpand: true);
+            sb.Append(OutputHead)
+                .Append(outputId).AppendFormat(applicationInfo.ApplicationId.Value, 'X', 16)
+                .Append(OutputVersion).AppendFormat(applicationInfo.Version >> 16, 'X', 4)
+                .Append(OutputTail);
+
+            _serviceImpl.OutputAccessLogToSdCard(sb.Buffer, applicationInfo.ApplicationId.Value, _processId);
+        }
+
+        return Result.Success;
     }
 
     public Result OutputMultiProgramTagAccessLog()
@@ -55,12 +105,8 @@ internal readonly struct AccessLogService
 
     public Result FlushAccessLogOnSdCard()
     {
-        throw new NotImplementedException();
-    }
-
-    private Result GetProgramInfo(out ProgramInfo programInfo)
-    {
-        return _serviceImpl.GetProgramInfo(out programInfo, _processId);
+        _serviceImpl.FlushAccessLogSdCardWriter();
+        return Result.Success;
     }
 
     /// <summary>"<c>FS_ACCESS: { multi_program_tag: true }\n</c>"</summary>
diff --git a/src/LibHac/FsSrv/AccessLogServiceImpl.cs b/src/LibHac/FsSrv/AccessLogServiceImpl.cs
index a919208c..90cba0dd 100644
--- a/src/LibHac/FsSrv/AccessLogServiceImpl.cs
+++ b/src/LibHac/FsSrv/AccessLogServiceImpl.cs
@@ -1,34 +1,56 @@
 using System;
+using LibHac.Diag;
 using LibHac.Fs;
 using LibHac.FsSrv.Impl;
+using LibHac.Os;
+using Utility = LibHac.FsSrv.Impl.Utility;
 
 namespace LibHac.FsSrv;
 
+/// <summary>
+/// Writes to the FS access log file on the SD card, filtering messages based on the current global log mode
+/// and the sending program's ID.
+/// </summary>
+/// <remarks>Based on nnSdk 18.3.0 (FS 18.0.0)</remarks>
 public class AccessLogServiceImpl : IDisposable
 {
     private Configuration _config;
     private GlobalAccessLogMode _accessLogMode;
+    private AccessLogSdCardWriter _sdCardWriter;
+    private SdkMutexType _mutex;
 
-    public AccessLogServiceImpl(in Configuration configuration)
-    {
-        _config = configuration;
-    }
-
-    public void Dispose()
-    {
-
-    }
+    public FileSystemServer FsServer => _config.FsServer;
 
     public struct Configuration
     {
-        public ulong MinimumProgramIdForSdCardLog;
+        public ulong ProgramIdWithoutPlatformIdMinForAccessLog;
 
         // LibHac additions
         public FileSystemServer FsServer;
     }
 
+    public AccessLogServiceImpl(in Configuration configuration)
+    {
+        _config = configuration;
+        _accessLogMode = GlobalAccessLogMode.None;
+        _sdCardWriter = new AccessLogSdCardWriter(configuration.FsServer.Hos.Fs);
+        _mutex = new SdkMutexType();
+    }
+
+    public void Dispose()
+    {
+        _sdCardWriter.Dispose();
+    }
+
     public void SetAccessLogMode(GlobalAccessLogMode mode)
     {
+        using ScopedLock<SdkMutexType> scopedLock = ScopedLock.Lock(ref _mutex);
+
+        if (_accessLogMode.HasFlag(GlobalAccessLogMode.SdCard) && !mode.HasFlag(GlobalAccessLogMode.SdCard))
+        {
+            _sdCardWriter.Flush();
+        }
+
         _accessLogMode = mode;
     }
 
@@ -44,22 +66,31 @@ public class AccessLogServiceImpl : IDisposable
 
     public Result OutputAccessLogToSdCard(ReadOnlySpan<byte> text, ulong programId, ulong processId)
     {
-        throw new NotImplementedException();
+        using ScopedLock<SdkMutexType> scopedLock = ScopedLock.Lock(ref _mutex);
+
+        if (!_accessLogMode.HasFlag(GlobalAccessLogMode.SdCard))
+            return Result.Success;
+
+        Assert.SdkRequiresNotEqual(_config.ProgramIdWithoutPlatformIdMinForAccessLog, 0ul);
+
+        if (Utility.ClearPlatformIdInProgramId(processId) >= _config.ProgramIdWithoutPlatformIdMinForAccessLog)
+        {
+            _sdCardWriter.AppendLog(text, programId);
+        }
+
+        return Result.Success;
     }
 
-    public Result FlushAccessLogSdCardWriter()
+    public void FlushAccessLogSdCardWriter()
     {
-        throw new NotImplementedException();
+        if (_accessLogMode.HasFlag(GlobalAccessLogMode.SdCard))
+        {
+            _sdCardWriter.Flush();
+        }
     }
 
-    public Result FinalizeAccessLogSdCardWriter()
+    public void FinalizeAccessLogSdCardWriter()
     {
-        throw new NotImplementedException();
-    }
-
-    internal Result GetProgramInfo(out ProgramInfo programInfo, ulong processId)
-    {
-        var registry = new ProgramRegistryImpl(_config.FsServer);
-        return registry.GetProgramInfo(out programInfo, processId);
+        _sdCardWriter.FinalizeObject();
     }
 }
\ No newline at end of file
diff --git a/src/LibHac/FsSrv/FileSystemServerInitializer.cs b/src/LibHac/FsSrv/FileSystemServerInitializer.cs
index 7c401007..4f5f77ef 100644
--- a/src/LibHac/FsSrv/FileSystemServerInitializer.cs
+++ b/src/LibHac/FsSrv/FileSystemServerInitializer.cs
@@ -170,7 +170,7 @@ public static class FileSystemServerInitializer
         var statusReportService = new StatusReportServiceImpl(in statusReportServiceConfig);
 
         var accessLogServiceConfig = new AccessLogServiceImpl.Configuration();
-        accessLogServiceConfig.MinimumProgramIdForSdCardLog = 0x0100000000003000;
+        accessLogServiceConfig.ProgramIdWithoutPlatformIdMinForAccessLog = 0x3000;
         accessLogServiceConfig.FsServer = server;
 
         var accessLogService = new AccessLogServiceImpl(in accessLogServiceConfig);