diff --git a/lib/src/osStopTimer.c b/lib/src/osStopTimer.c
new file mode 100644
index 00000000..e9ec69bb
--- /dev/null
+++ b/lib/src/osStopTimer.c
@@ -0,0 +1,33 @@
+#include "libultra_internal.h"
+#include "osint.h"
+
+#pragma GCC diagnostic ignored "-Wunused-but-set-variable"
+
+// FROM https://github.com/ModernN64SDKArchives/libultra_modern
+int osStopTimer(OSTimer* t) {
+    register u32 savedMask;
+    OSTimer* timep;
+
+    if (t->next == NULL) {
+        return -1;
+    }
+
+    savedMask = __osDisableInt();
+    timep = t->next;
+
+    if (timep != __osTimerList) {
+        timep->remaining += t->remaining;
+    }
+
+    t->prev->next = t->next;
+    t->next->prev = t->prev;
+    t->next = NULL;
+    t->prev = NULL;
+
+    if (__osTimerList->next == __osTimerList) {
+        __osSetCompare(0);
+    }
+
+    __osRestoreInt(savedMask);
+    return 0;
+}
diff --git a/sm64.ld b/sm64.ld
index c4c308da..7258de54 100755
--- a/sm64.ld
+++ b/sm64.ld
@@ -267,7 +267,9 @@ SECTIONS
         BUILD_DIR/libultra.a:__osGetCause.o(.text);
         BUILD_DIR/libultra.a:__osAtomicDec.o(.text);
         BUILD_DIR/libultra.a:guLookAtRef.o(.text); /* Fast3DEX2 only */
+        BUILD_DIR/libultra.a:__osGetCurrFaultedThread.o(.text);
         BUILD_DIR/libultra.a:osSyncPrintf.o(.text);
+        BUILD_DIR/libultra.a:osStopTimer.o(.text);
         BUILD_DIR/lib/rsp.o(.text);
 
         /* data */
diff --git a/src/game/crash.c b/src/game/crash.c
new file mode 100644
index 00000000..7c3ef35d
--- /dev/null
+++ b/src/game/crash.c
@@ -0,0 +1,192 @@
+#include <ultra64.h>
+#include <stdarg.h>
+#include <string.h>
+
+#include "sm64.h"
+
+#if defined(TARGET_N64)
+
+char *gCauseDesc[18] = {
+    "Interrupt",
+    "TLB modification",
+    "TLB exception on load",
+    "TLB exception on store",
+    "Address error on load",
+    "Address error on store",
+    "Bus error on inst.",
+    "Bus error on data",
+    "System call exception",
+    "Breakpoint exception",
+    "Reserved instruction",
+    "Coprocessor unusable",
+    "Arithmetic overflow",
+    "Trap exception",
+    "Virtual coherency on inst.",
+    "Floating point exception",
+    "Watchpoint exception",
+    "Virtual coherency on data",
+};
+
+char *gFpcsrDesc[6] = {
+    "Unimplemented operation", "Invalid operation", "Division by zero", "Overflow", "Underflow",
+    "Inexact operation",
+};
+
+extern uintptr_t gPhysicalFramebuffers[3];
+extern u16 sRenderedFramebuffer;
+extern u64 osClockRate;
+
+struct {
+    OSThread thread;
+    u64 stack[0x800 / sizeof(u64)];
+    OSMesgQueue mesgQueue;
+    OSMesg mesg;
+    char *errorMsg;
+} gCrashLogger;
+
+#define crash_logger_print rmonpf
+
+void crash_logger_print_float_reg(s32 regNum, void *addr) {
+    u32 bits;
+    s32 exponent;
+
+    bits = *(u32 *) addr;
+    exponent = ((bits & 0x7f800000U) >> 0x17) - 0x7f;
+    if ((exponent >= -0x7e && exponent <= 0x7f) || bits == 0) {
+        crash_logger_print("F%02d:%.3e  ", regNum, *(f32 *) addr);
+    } else {
+        crash_logger_print("F%02d:--------- ", regNum);
+    }
+}
+
+void crash_logger_print_fpcsr(u32 fpcsr) {
+    s32 i;
+    u32 bit;
+
+    bit = 1 << 17;
+    crash_logger_print("FPCSR:%08XH", fpcsr);
+    for (i = 0; i < 6; i++) {
+        if (fpcsr & bit) {
+            crash_logger_print("  (%s)", gFpcsrDesc[i]);
+            return;
+        }
+        bit >>= 1;
+    }
+}
+
+void print_crash(OSThread *thread) {
+    s16 cause;
+    __OSThreadContext *tc = &thread->context;
+
+    cause = (tc->cause >> 2) & 0x1f;
+    if (cause == 23) { // EXC_WATCH
+        cause = 16;
+    }
+    if (cause == 31) { // EXC_VCED
+        cause = 17;
+    }
+
+    crash_logger_print("THREAD:%d  (%s)\n", thread->id, gCauseDesc[cause]);
+    crash_logger_print("PC:%08XH   SR:%08XH   VA:%08XH\n\n", tc->pc, tc->sr, tc->badvaddr);
+    osWritebackDCacheAll();
+    crash_logger_print("AT:%08XH   V0:%08XH   V1:%08XH\n", (u32) tc->at, (u32) tc->v0,
+                       (u32) tc->v1);
+    crash_logger_print("A0:%08XH   A1:%08XH   A2:%08XH\n", (u32) tc->a0, (u32) tc->a1,
+                       (u32) tc->a2);
+    crash_logger_print("A3:%08XH   T0:%08XH   T1:%08XH\n", (u32) tc->a3, (u32) tc->t0,
+                       (u32) tc->t1);
+    crash_logger_print("T2:%08XH   T3:%08XH   T4:%08XH\n", (u32) tc->t2, (u32) tc->t3,
+                       (u32) tc->t4);
+    crash_logger_print("T5:%08XH   T6:%08XH   T7:%08XH\n", (u32) tc->t5, (u32) tc->t6,
+                       (u32) tc->t7);
+    crash_logger_print("S0:%08XH   S1:%08XH   S2:%08XH\n", (u32) tc->s0, (u32) tc->s1,
+                       (u32) tc->s2);
+    crash_logger_print("S3:%08XH   S4:%08XH   S5:%08XH\n", (u32) tc->s3, (u32) tc->s4,
+                       (u32) tc->s5);
+    crash_logger_print("S6:%08XH   S7:%08XH   T8:%08XH\n", (u32) tc->s6, (u32) tc->s7,
+                       (u32) tc->t8);
+    crash_logger_print("T9:%08XH   GP:%08XH   SP:%08XH\n", (u32) tc->t9, (u32) tc->gp,
+                       (u32) tc->sp);
+    crash_logger_print("S8:%08XH   RA:%08XH\n\n", (u32) tc->s8, (u32) tc->ra);
+    crash_logger_print_fpcsr(tc->fpcsr);
+    osWritebackDCacheAll();
+    crash_logger_print("\n\n");
+    crash_logger_print_float_reg(0, &tc->fp0.f.f_even);
+    crash_logger_print_float_reg(2, &tc->fp2.f.f_even);
+    crash_logger_print_float_reg(4, &tc->fp4.f.f_even);
+    crash_logger_print("\n");
+    crash_logger_print_float_reg(6, &tc->fp6.f.f_even);
+    crash_logger_print_float_reg(8, &tc->fp8.f.f_even);
+    crash_logger_print_float_reg(10, &tc->fp10.f.f_even);
+    crash_logger_print("\n");
+    crash_logger_print_float_reg(12, &tc->fp12.f.f_even);
+    crash_logger_print_float_reg(14, &tc->fp14.f.f_even);
+    crash_logger_print_float_reg(16, &tc->fp16.f.f_even);
+    crash_logger_print("\n");
+    crash_logger_print_float_reg(18, &tc->fp18.f.f_even);
+    crash_logger_print_float_reg(20, &tc->fp20.f.f_even);
+    crash_logger_print_float_reg(22, &tc->fp22.f.f_even);
+    crash_logger_print("\n");
+    crash_logger_print_float_reg(24, &tc->fp24.f.f_even);
+    crash_logger_print_float_reg(26, &tc->fp26.f.f_even);
+    crash_logger_print_float_reg(28, &tc->fp28.f.f_even);
+    crash_logger_print("\n");
+    crash_logger_print_float_reg(30, &tc->fp30.f.f_even);
+    osWritebackDCacheAll();
+}
+
+void freeze_screen() {
+    osViBlack(FALSE);
+    osViSwapBuffer((u16 *)(gPhysicalFramebuffers[sRenderedFramebuffer] | 0xa0000000));
+}
+
+OSThread *get_crashed_thread(void) {
+    OSThread *thread;
+
+    thread = __osGetCurrFaultedThread();
+    while (thread->priority != -1) {
+        if (thread->priority > OS_PRIORITY_IDLE && thread->priority < OS_PRIORITY_APPMAX
+            && (thread->flags & 3) != 0) {
+            return thread;
+        }
+        thread = thread->tlnext;
+    }
+    return NULL;
+}
+
+void error(char *msg) {
+    gCrashLogger.errorMsg = msg;
+    *(vs8*)0 = 0;
+}
+
+void thread2_crash_logger(UNUSED void *arg) {
+    OSMesg mesg;
+    OSThread *thread;
+
+    osSetEventMesg(OS_EVENT_CPU_BREAK, &gCrashLogger.mesgQueue, (OSMesg) 1);
+    osSetEventMesg(OS_EVENT_FAULT, &gCrashLogger.mesgQueue, (OSMesg) 2);
+    do {
+        osRecvMesg(&gCrashLogger.mesgQueue, &mesg, 1);
+        thread = get_crashed_thread();
+    } while (thread == NULL);
+    if (gCrashLogger.errorMsg) {
+        crash_logger_print(gCrashLogger.errorMsg);
+    } else {
+        print_crash(thread);
+    }
+    freeze_screen();
+    for (;;) {
+    }
+}
+
+void crash_log_init(void) {
+    osCreateMesgQueue(&gCrashLogger.mesgQueue, &gCrashLogger.mesg, 1);
+    osCreateThread(
+        &gCrashLogger.thread, 2, thread2_crash_logger, NULL,
+        (u8 *) gCrashLogger.stack + sizeof(gCrashLogger.stack),
+        OS_PRIORITY_RMON
+    );
+    osStartThread(&gCrashLogger.thread);
+}
+
+#endif
diff --git a/src/game/crash.h b/src/game/crash.h
new file mode 100644
index 00000000..ce7a0809
--- /dev/null
+++ b/src/game/crash.h
@@ -0,0 +1,9 @@
+#ifndef CRASH_H
+#define CRASH_H
+
+#include <PR/ultratypes.h>
+
+extern void error(char *msg);
+extern void crash_log_init(void);
+
+#endif // DEBUG_H
diff --git a/src/game/main.c b/src/game/main.c
index 02decc9d..e6602730 100644
--- a/src/game/main.c
+++ b/src/game/main.c
@@ -1,5 +1,6 @@
 #include <ultra64.h>
 #include <stdio.h>
+#include "PR/os.h"
 
 #include "sm64.h"
 #include "audio/external.h"
@@ -11,12 +12,14 @@
 #include "segments.h"
 #include "segment_symbols.h"
 #include "main.h"
+#include "crash.h"
 
 // Message IDs
 #define MESG_SP_COMPLETE 100
 #define MESG_DP_COMPLETE 101
 #define MESG_VI_VBLANK 102
 #define MESG_START_GFX_SPTASK 103
+#define MESG_RCP_HUNG 105
 
 OSThread gRmonThread; // unused?
 OSThread gIdleThread;
@@ -312,6 +315,27 @@ void handle_dp_complete(void) {
     sCurrentDisplaySPTask = NULL;
 }
 
+/////// FROM https://github.com/HackerN64/HackerSM64, START
+#if defined(TARGET_N64)
+OSTimerEx RCPHangTimer;
+void start_rcp_hang_timer(void) {
+    if (RCPHangTimer.started == FALSE) {
+        osSetTimer(&RCPHangTimer.timer, OS_USEC_TO_CYCLES(3000000), (OSTime) 0, &gIntrMesgQueue, (OSMesg) MESG_RCP_HUNG);
+        RCPHangTimer.started = TRUE;
+    }
+}
+
+void stop_rcp_hang_timer(void) {
+    osStopTimer(&RCPHangTimer.timer);
+    RCPHangTimer.started = FALSE;
+}
+
+void alert_rcp_hung_up(void) {
+    error("RCP IS HUNG UP! Please check your display lists for any errors.");
+}
+#endif
+/////// END
+
 void thread3_main(UNUSED void *arg) {
     create_thread(&gSoundThread, 4, thread4_sound, NULL, gThread4Stack + 0x2000, 20);
     osStartThread(&gSoundThread);
@@ -323,6 +347,9 @@ void thread3_main(UNUSED void *arg) {
     alloc_pool();
     load_engine_code_segment(); // this line is not in the Feburary 1996 backup, but WHERE ELSE WOULD
                                 // THE DATA BE LOADED THEN?
+#if defined(TARGET_N64)
+    crash_log_init();           // this is not john nintendo approved
+#endif
 
     while (TRUE) {
         OSMesg msg;
@@ -336,11 +363,22 @@ void thread3_main(UNUSED void *arg) {
                 handle_sp_complete();
                 break;
             case MESG_DP_COMPLETE:
+#if defined(TARGET_N64)
+                stop_rcp_hang_timer();
+#endif
                 handle_dp_complete();
                 break;
             case MESG_START_GFX_SPTASK:
+#if defined(TARGET_N64)
+                start_rcp_hang_timer();
+#endif
                 start_gfx_sptask();
                 break;
+#if defined(TARGET_N64)
+            case MESG_RCP_HUNG:
+                alert_rcp_hung_up();
+                break;
+#endif
         }
         CheckStackMemory();
     }
diff --git a/src/game/main.h b/src/game/main.h
index 16e02140..e89ef1ec 100644
--- a/src/game/main.h
+++ b/src/game/main.h
@@ -32,6 +32,18 @@ extern s8 D_8032C650;
 extern s8 gShowProfiler;
 extern s8 gShowDebugText;
 
+/////// FROM https://github.com/HackerN64/HackerSM64, START
+// Special struct that keeps track of whether its timer has been set.
+//  Without this check, there is a bug at high CPU loads in which
+//  the RCP timer gets set twice and the game tries to
+//  insert __osBaseTimer into a ring buffer that only contains itself,
+//  causing a particularly messy crash.
+typedef struct {
+    u8 started;
+    OSTimer timer;
+} OSTimerEx;
+/////// END
+
 void set_vblank_handler(s32 index, struct VblankHandler *handler, OSMesgQueue *queue, OSMesg *msg);
 void dispatch_audio_sptask(struct SPTask *spTask);
 void exec_display_list(struct SPTask *spTask);