diff --git a/librecomp/src/pak.cpp b/librecomp/src/pak.cpp
index 0be1513..df86301 100644
--- a/librecomp/src/pak.cpp
+++ b/librecomp/src/pak.cpp
@@ -1,51 +1,278 @@
+#include <filesystem>
+#include <fstream>
 #include "ultramodern/ultra64.h"
 #include "ultramodern/ultramodern.hpp"
 
 #include "recomp.h"
 #include "helpers.hpp"
 
-extern "C" void osPfsInitPak_recomp(uint8_t * rdram, recomp_context* ctx) {
-    ctx->r2 = 1; // PFS_ERR_NOPACK
+typedef struct ControllerPak {
+    OSPfsState state;
+    FILE* file;
+} ControllerPak;
+
+static ControllerPak sControllerPak[16];
+static int sFileSelect = 0;
+
+void ByteSwapFile(u8* buffer, size_t size) {
+    uint8_t c0, c1, c2, c3;
+
+    for (size_t i = 0; i < size; i += 4) {
+        c0 = buffer[i + 0];
+        c1 = buffer[i + 1];
+        c2 = buffer[i + 2];
+        c3 = buffer[i + 3];
+
+        buffer[i + 3] = c0;
+        buffer[i + 2] = c1;
+        buffer[i + 1] = c2;
+        buffer[i + 0] = c3;
+    }
 }
 
-extern "C" void osPfsFreeBlocks_recomp(uint8_t * rdram, recomp_context * ctx) {
-    ctx->r2 = 1; // PFS_ERR_NOPACK
+// s32 osPfsIsPlug(OSMesgQueue* mq, u8* pattern)
+extern "C" void osPfsIsPlug_recomp(uint8_t* rdram, recomp_context* ctx) {
+    MEM_B(0, ctx->r5) = 1; // *pattern = 1;
+    ctx->r2 = 0;           // PFS_NO_ERROR
 }
 
-extern "C" void osPfsAllocateFile_recomp(uint8_t * rdram, recomp_context * ctx) {
-    ctx->r2 = 1; // PFS_ERR_NOPACK
+// s32 osPfsInit(OSMesgQueue* queue, OSPfs* pfs, int channel) {
+extern "C" void osPfsInit_recomp(uint8_t* rdram, recomp_context* ctx) {
+    OSMesgQueue* queue = _arg<0, OSMesgQueue*>(rdram, ctx);
+    OSPfs* pfs = _arg<1, OSPfs*>(rdram, ctx);
+    s32 channel = _arg<2, s32>(rdram, ctx);
+
+    pfs->queue = (int32_t) queue;
+    pfs->channel = channel;
+    pfs->status = 0x1;
+
+    ctx->r2 = 0; // PFS_NO_ERROR
 }
 
-extern "C" void osPfsDeleteFile_recomp(uint8_t * rdram, recomp_context * ctx) {
-    ctx->r2 = 1; // PFS_ERR_NOPACK
+// s32 osPfsInitPak(OSMesgQueue* queue, OSPfs* pfs, int channel);
+extern "C" void osPfsInitPak_recomp(uint8_t* rdram, recomp_context* ctx) {
+    OSMesgQueue* queue = _arg<0, OSMesgQueue*>(rdram, ctx);
+    OSPfs* pfs = _arg<1, OSPfs*>(rdram, ctx);
+    s32 channel = _arg<2, s32>(rdram, ctx);
+
+    pfs->queue = (int32_t) queue;
+    pfs->channel = channel;
+    pfs->status = 0x1;
+
+    ctx->r2 = 0; // PFS_NO_ERROR
 }
 
-extern "C" void osPfsFileState_recomp(uint8_t * rdram, recomp_context * ctx) {
-    ctx->r2 = 1; // PFS_ERR_NOPACK
+// s32 osPfsFreeBlocks(OSPfs* pfs, s32* bytes_not_used);
+extern "C" void osPfsFreeBlocks_recomp(uint8_t* rdram, recomp_context* ctx) {
+    s32* bytes_not_used = _arg<1, s32*>(rdram, ctx);
+
+    *bytes_not_used = 123 << 8;
+
+    ctx->r2 = 0; // PFS_NO_ERROR
 }
 
-extern "C" void osPfsFindFile_recomp(uint8_t * rdram, recomp_context * ctx) {
-    ctx->r2 = 1; // PFS_ERR_NOPACK
+// TODO: VALIDATE
+// Can't really be validated without a valid controller pak file system header, which is only used
+// by the controller pak manager present in games by holding START on boot and not necessary for recomp.
+// s32 osPfsAllocateFile(OSPfs* pfs, u16 company_code, u32 game_code, u8* game_name, u8* ext_name,
+// int file_size_in_bytes, s32* file_no);
+extern "C" void osPfsAllocateFile_recomp(uint8_t* rdram, recomp_context* ctx) {
+    u16 company_code = _arg<1, u16>(rdram, ctx);
+    u32 game_code = _arg<2, u32>(rdram, ctx);
+    u8* game_name = _arg<3, u8*>(rdram, ctx);
+    u8* ext_name = TO_PTR(u8, MEM_W(0x10, ctx->r29));
+    s32 file_size_in_bytes = (s32) MEM_W(0x14, ctx->r29);
+    s32* file_no = TO_PTR(s32, MEM_W(0x18, ctx->r29));
+
+    ControllerPak* pak = &sControllerPak[*file_no];
+
+    printf("osPfsAllocateFile_recomp:\n");
+
+    *file_no = sFileSelect++;
+
+    char filename[100];
+    sprintf(filename, "controllerPak_file_%d.sav", *file_no);
+    pak->file = fopen(filename, "wb+");
+
+    file_size_in_bytes = (file_size_in_bytes + 31) & ~31;
+
+    u8* zero_block = (u8*) malloc(file_size_in_bytes);
+    memset(zero_block, 0, file_size_in_bytes);
+    fwrite(zero_block, file_size_in_bytes, 1, pak->file);
+
+    pak->state.company_code = company_code;
+    pak->state.game_code = game_code;
+    strcpy(pak->state.game_name, (const char*) game_name);
+    strcpy(pak->state.ext_name, (const char*) ext_name);
+
+    ctx->r2 = 0; // PFS_NO_ERROR
 }
 
-extern "C" void osPfsReadWriteFile_recomp(uint8_t * rdram, recomp_context * ctx) {
-    ctx->r2 = 1; // PFS_ERR_NOPACK
+// TODO: VALIDATE
+// Can't really be validated without a valid controller pak file system header, which is only used
+// by the controller pak manager present in games by holding START on boot and not necessary for recomp.
+// s32 osPfsDeleteFile(OSPfs* pfs, u16 company_code, u32 game_code, u8* game_name, u8* ext_name);
+extern "C" void osPfsDeleteFile_recomp(uint8_t* rdram, recomp_context* ctx) {
+    u16 company_code = _arg<1, u16>(rdram, ctx);
+    u32 game_code = _arg<2, u32>(rdram, ctx);
+    u8* game_name = _arg<3, u8*>(rdram, ctx);
+    u8* ext_name = TO_PTR(u8, MEM_W(0x10, ctx->r29));
+    s32 file_no;
+
+    printf("osPfsDeleteFile_recomp:\n");
+
+    for (size_t i = 0; i < ARRAYSIZE(sControllerPak); i++) {
+        if ((sControllerPak[i].state.company_code = company_code) && (sControllerPak[i].state.game_code == game_code) &&
+            (strcmp(sControllerPak[i].state.game_name, (const char*) game_name) == 0) &&
+            strcmp(sControllerPak[i].state.ext_name, (const char*) ext_name) == 0) {
+            file_no = i;
+
+            char filename[100];
+            sprintf(filename, "controllerPak_file_%d.sav", file_no);
+            remove(filename);
+
+            ctx->r2 = 0; // PFS_NO_ERROR
+            printf("Returned 0: FILE DELETED\n\n");
+            return;
+        } else {
+            ctx->r2 = 1; // PFS_ERR_NOPACK
+            printf("Returned 1: FILE NOT FOUND\n\n");
+        }
+    }
 }
 
-extern "C" void osPfsChecker_recomp(uint8_t * rdram, recomp_context * ctx) {
-    ctx->r2 = 1; // PFS_ERR_NOPACK
+bool IsFileEmpty(FILE* file, s32 file_no) {
+    u8 data_buffer[256];
+
+    fseek(file, 0, SEEK_SET);
+    fread(data_buffer, 0x100, 1, file);
+
+    long current = ftell(file);
+    fseek(file, 0, SEEK_END);
+    long size = ftell(file);
+    fseek(file, current, SEEK_SET);
+
+    return size == 0;
 }
 
-extern "C" void osPfsNumFiles_recomp(uint8_t * rdram, recomp_context * ctx) {
+// s32 osPfsFileState(OSPfs* pfs, s32 file_no, OSPfsState* state);
+extern "C" void osPfsFileState_recomp(uint8_t* rdram, recomp_context* ctx) {
+    s32 file_no = _arg<1, s32>(rdram, ctx);
+    OSPfsState* state = _arg<2, OSPfsState*>(rdram, ctx);
+
+    ControllerPak* pak = &sControllerPak[file_no];
+
+    char filename[100];
+    sprintf(filename, "controllerPak_file_%d.sav", file_no);
+    pak->file = fopen(filename, "rb+");
+    if (pak->file == NULL) {
+        pak->file = fopen(filename, "wb+");
+    }
+
+    if (!IsFileEmpty(pak->file, file_no)) {
+        state->file_size = pak->state.file_size;
+        state->company_code = pak->state.company_code;
+        state->game_code = pak->state.game_code;
+
+        for (size_t j = 0; j < ARRAYSIZE(pak->state.game_name); j++) {
+            state->game_name[j] = pak->state.game_name[j];
+        }
+        for (size_t j = 0; j < ARRAYSIZE(pak->state.ext_name); j++) {
+            state->ext_name[j] = pak->state.ext_name[j];
+        }
+
+        fclose(pak->file);
+        ctx->r2 = 0; // PFS_NO_ERROR
+    } else {
+        fclose(pak->file);
+        remove(filename);
+        ctx->r2 = 1; // PFS_ERR_NOPACK
+    }
+}
+
+// s32 osPfsFindFile(OSPfs* pfs, u16 company_code, u32 game_code, u8* game_name, u8* ext_name, s32* file_no);
+extern "C" void osPfsFindFile_recomp(uint8_t* rdram, recomp_context* ctx) {
+    u16 company_code = _arg<1, u16>(rdram, ctx);
+    u32 game_code = _arg<2, u32>(rdram, ctx);
+    u8* game_name = _arg<3, u8*>(rdram, ctx);
+    u8* ext_name = TO_PTR(u8, MEM_W(0x10, ctx->r29));
+    s32* file_no = TO_PTR(s32, MEM_W(0x14, ctx->r29));
+
+    for (size_t i = 0; i < ARRAYSIZE(sControllerPak); i++) {
+        if ((sControllerPak[i].state.game_code == game_code) &&
+            (sControllerPak[i].state.company_code == company_code) &&
+            (strcmp(sControllerPak[i].state.game_name, (const char*) game_name) == 0) &&
+            strcmp(sControllerPak[i].state.ext_name, (const char*) ext_name) == 0) {
+            // File found
+            *file_no = i;
+            ctx->r2 = 0; // PFS_NO_ERROR
+            return;
+        }
+    }
+
+    // Open file
+    *file_no = sFileSelect++;
+
+    char filename[100];
+    sprintf(filename, "controllerPak_file_%d.sav", *file_no);
+    sControllerPak[*file_no].file = fopen(filename, "rb+");
+    if (sControllerPak[*file_no].file == NULL) {
+        sControllerPak[*file_no].file = fopen(filename, "wb+");
+    }
+
+    sControllerPak[*file_no].state.company_code = company_code;
+    sControllerPak[*file_no].state.game_code = game_code;
+    strcpy(sControllerPak[*file_no].state.game_name, (const char*) game_name);
+    strcpy(sControllerPak[*file_no].state.ext_name, (const char*) ext_name);
+
+    ctx->r2 = 0; // PFS_NO_ERROR
+}
+
+// s32 osPfsReadWriteFile(OSPfs* pfs, s32 file_no, u8 flag, int offset, int size_in_bytes, u8* data_buffer);
+extern "C" void osPfsReadWriteFile_recomp(uint8_t* rdram, recomp_context* ctx) {
+    s32 file_no = _arg<1, s32>(rdram, ctx);
+    u8 flag = _arg<2, u8>(rdram, ctx);
+    s32 offset = _arg<3, s32>(rdram, ctx);
+    s32 size_in_bytes = (s32) MEM_W(0x10, ctx->r29);
+    u8* data_buffer = TO_PTR(u8, MEM_W(0x14, ctx->r29));
+
+    ControllerPak* pak = &sControllerPak[file_no];
+
+    if (flag == 0) {
+        fseek(pak->file, offset, SEEK_SET);
+        fread(data_buffer, size_in_bytes, 1, pak->file);
+        ByteSwapFile(data_buffer, size_in_bytes);
+    } else {
+        ByteSwapFile(data_buffer, size_in_bytes);
+        fseek(pak->file, offset, SEEK_SET);
+        fwrite(data_buffer, size_in_bytes, 1, pak->file);
+    }
+
+    ctx->r2 = 0; // PFS_NO_ERROR
+}
+
+extern "C" void osPfsChecker_recomp(uint8_t* rdram, recomp_context* ctx) {
+    ctx->r2 = 0; // PFS_NO_ERROR
+}
+
+// s32 osPfsNumFiles(OSPfs* pfs, s32* max_files, s32* files_used);
+extern "C" void osPfsNumFiles_recomp(uint8_t* rdram, recomp_context* ctx) {
     s32* max_files = _arg<1, s32*>(rdram, ctx);
     s32* files_used = _arg<2, s32*>(rdram, ctx);
 
-    *max_files = 0;
-    *files_used = 0;
+    u8 files = 0;
+    for (size_t i = 0; i < ARRAYSIZE(sControllerPak); i++) {
+        if ((sControllerPak[i].state.company_code != 0) && (sControllerPak[i].state.game_code != 0)) {
+            files++;
+        }
+    }
 
-    _return<s32>(ctx, 1); // PFS_ERR_NOPACK
+    *files_used = files;
+    *max_files = ARRAYSIZE(sControllerPak);
+
+    ctx->r2 = 0; // PFS_NO_ERROR
 }
 
-extern "C" void osPfsRepairId_recomp(uint8_t * rdram, recomp_context * ctx) {
+extern "C" void osPfsRepairId_recomp(uint8_t* rdram, recomp_context* ctx) {
     _return<s32>(ctx, 1); // PFS_ERR_NOPACK
 }
diff --git a/ultramodern/include/ultramodern/ultra64.h b/ultramodern/include/ultramodern/ultra64.h
index 71a412f..8b136cf 100644
--- a/ultramodern/include/ultramodern/ultra64.h
+++ b/ultramodern/include/ultramodern/ultra64.h
@@ -235,6 +235,13 @@ typedef struct {
     u8 banks;
 } OSPfs;
 
+typedef struct {
+    /* 0x00 */ u32 file_size; /* bytes */
+    /* 0x04 */ u32 game_code;
+    /* 0x08 */ u16 company_code;
+    /* 0x0C */ char ext_name[4];
+    /* 0x10 */ char game_name[16];
+} OSPfsState; // size = 0x20
 
 // Controller