diff --git a/recompiler/CMakeLists.txt b/recompiler/CMakeLists.txt
index 42abc0da..90fee787 100644
--- a/recompiler/CMakeLists.txt
+++ b/recompiler/CMakeLists.txt
@@ -789,6 +789,11 @@ if(BUILD_TESTING)
         add_test(NAME tas_replay_recipe
             COMMAND ${Python3_EXECUTABLE}
                 "${CMAKE_CURRENT_SOURCE_DIR}/../tools/tasreplays/test_tekken3.py")
+        # The Python driver compiles test_source_ram_page_probe.c at O0/O2.
+        add_test(NAME tas_ram_long_route
+            COMMAND ${Python3_EXECUTABLE}
+                "${CMAKE_CURRENT_SOURCE_DIR}/../runtime/tests/test_source_ram_page_probe.py"
+                --cc ${CMAKE_C_COMPILER})
     endif()
 endif()
 
diff --git a/runtime/include/source_ram_page_probe.h b/runtime/include/source_ram_page_probe.h
index 7ac6569d..e4c8fbba 100644
--- a/runtime/include/source_ram_page_probe.h
+++ b/runtime/include/source_ram_page_probe.h
@@ -17,17 +17,31 @@ static uint64_t source_ram_page_hash(const uint8_t *bytes, unsigned count) {
 static void source_ram_page_probe(unsigned frame, uint64_t cycle) {
     static int initialized, enabled;
     static FILE *stream;
-    static unsigned snapshots[32], snapshot_count;
+    static unsigned snapshots[32], snapshot_count, max_frames = 20000;
     if (!initialized) {
         initialized = 1;
         const char *setting = getenv("PSX_SOURCE_RAM_PAGE_PROBE");
         enabled = setting && strcmp(setting, "1") == 0;
+        const char *limit = getenv("PSX_SOURCE_RAM_MAX_FRAMES");
+        if (enabled && limit) {
+            /* A declared route may exceed the historical short-TAS bound.
+             * Parse without strtoul overflow or accepting signs/whitespace. */
+            unsigned value = 0;
+            if (!*limit) abort();
+            for (const char *p = limit; *p; ++p) {
+                if (*p < '0' || *p > '9' || value > 100000) abort();
+                value = value * 10 + (unsigned)(*p - '0');
+                if (value > 1000000) abort();
+            }
+            if (!value) abort();
+            max_frames = value;
+        }
         const char *cursor = getenv("PSX_SOURCE_RAM_SNAPSHOT_FRAMES");
         while (enabled && cursor && *cursor) {
             if (*cursor < '0' || *cursor > '9') abort();
             char *end;
             unsigned long value = strtoul(cursor, &end, 10);
-            if (end == cursor || value < 1 || value > 20000 || snapshot_count == 32 ||
+            if (end == cursor || value < 1 || value > max_frames || snapshot_count == 32 ||
                 (*end && *end != ',')) abort();
             for (unsigned i = 0; i < snapshot_count; ++i)
                 if (snapshots[i] == value) abort();
@@ -37,7 +51,7 @@ static void source_ram_page_probe(unsigned frame, uint64_t cycle) {
         }
     }
     if (!enabled) return;
-    if (frame < 1 || frame > 20000) abort();
+    if (frame < 1 || frame > max_frames) abort();
     extern uint8_t *memory_get_ram_ptr(void);
     const uint8_t *ram = memory_get_ram_ptr();
     char path[4096];
diff --git a/runtime/tests/test_source_ram_page_probe.c b/runtime/tests/test_source_ram_page_probe.c
new file mode 100644
index 00000000..ca57f1cf
--- /dev/null
+++ b/runtime/tests/test_source_ram_page_probe.c
@@ -0,0 +1,14 @@
+/* Exercise the production diagnostic with synthetic RAM, including long movies. */
+#include "source_ram_page_probe.h"
+#include <signal.h>
+static uint8_t test_ram[2097152];
+uint8_t *memory_get_ram_ptr(void) { return test_ram; }
+static void expected_abort(int ignored) { (void)ignored; exit(4); }
+int main(int argc, char **argv) {
+    signal(SIGABRT, expected_abort);
+    if (argc != 2) return 2;
+    test_ram[0] = 0x34;
+    test_ram[2097151] = 0xab;
+    source_ram_page_probe((unsigned)strtoul(argv[1], NULL, 10), UINT64_C(40500000000));
+    return 0;
+}
diff --git a/runtime/tests/test_source_ram_page_probe.py b/runtime/tests/test_source_ram_page_probe.py
new file mode 100644
index 00000000..42b9d156
--- /dev/null
+++ b/runtime/tests/test_source_ram_page_probe.py
@@ -0,0 +1,60 @@
+"""Long-route coverage and fail-closed bounds using the actual RAM observer."""
+import argparse
+import os
+from pathlib import Path
+import subprocess
+import tempfile
+
+def fnv(data):
+    h = 14695981039346656037
+    for byte in data:
+        h = ((h ^ byte) * 1099511628211) & 0xffffffffffffffff
+    return f'{h:016X}'
+
+def main():
+    p = argparse.ArgumentParser()
+    p.add_argument('--cc', default='gcc')
+    a = p.parse_args()
+    here = Path(__file__).resolve().parent
+    ram = bytearray(2097152)
+    ram[0], ram[-1] = 0x34, 0xab
+    zero = fnv(bytes(4096))
+    expected = [fnv(ram[:4096])] + [zero]*510 + [fnv(ram[-4096:])]
+    cases = [('legacy',None,20000,None,0),
+             ('legacy_limit',None,20001,None,4),
+             ('pepsiman','71806',71806,'71806',0),
+             ('re1','227202',227202,'227202',0),
+             ('bound','71806',71807,None,4),
+             ('snapshot_bound','71806',1,'71807',4),
+             ('duplicate','71806',1,'71806,71806',4),
+             ('zero','0',1,None,4), ('negative','-1',1,None,4),
+             ('junk','71806x',1,None,4), ('overflow','999999999999999999999',1,None,4),
+             ('space',' 71806',1,None,4), ('over_cap','1000001',1,None,4)]
+    with tempfile.TemporaryDirectory() as temporary:
+        root=Path(temporary)
+        for opt in ['-O0','-O2']:
+            exe=root/('probe'+opt+('.exe' if os.name=='nt' else ''))
+            subprocess.run([a.cc,'-std=c11',opt,'-Wall','-Wextra','-Werror',
+                            '-I'+str(here.parent/'include'),str(here/'test_source_ram_page_probe.c'),
+                            '-o',str(exe)],check=True)
+            for name,limit,frame,snapshot,code in cases:
+                out=root/(name+opt)
+                out.mkdir()
+                env={k:v for k,v in os.environ.items() if not k.startswith('PSX_')}
+                env.update(PSX_SOURCE_RAM_PAGE_PROBE='1',PSX_INPUT_ROUTE_CAPTURE_DIR=str(out))
+                if limit is not None: env['PSX_SOURCE_RAM_MAX_FRAMES']=limit
+                if snapshot: env['PSX_SOURCE_RAM_SNAPSHOT_FRAMES']=snapshot
+                result=subprocess.run([str(exe),str(frame)],env=env,capture_output=True,timeout=20)
+                assert result.returncode==code,(opt,name,result.returncode,code,result.stderr)
+                if code==0:
+                    rows=(out/'ram-pages.tsv').read_text().splitlines()
+                    assert len(rows)==3,(name,len(rows))
+                    row=rows[2].split('\t')
+                    assert row[:2]==[str(frame),'40500000000'] and row[2:]==expected,name
+                    if snapshot:
+                        assert (out/f'ram-frame-{frame:06d}.bin').read_bytes()==ram,name
+                else:
+                    assert not (out/'ram-pages.tsv').exists(),name
+    print(f'PASS: {len(cases)*2} production RAM observer cases; all 512 pages, clocks and late raw snapshots')
+
+if __name__=='__main__': main()
diff --git a/tools/tasreplays/run_native.py b/tools/tasreplays/run_native.py
index bc29bf71..a5c1a099 100644
--- a/tools/tasreplays/run_native.py
+++ b/tools/tasreplays/run_native.py
@@ -149,8 +149,8 @@ def main():
         raise ValueError('RAM page probe requires source raster frontend boundaries')
     if args.ram_snapshot_frame and (not args.ram_page_probe or len(args.ram_snapshot_frame)>32 or
             len(set(args.ram_snapshot_frame))!=len(args.ram_snapshot_frame) or
-            any(f<1 or f>20000 for f in args.ram_snapshot_frame)):
-        raise ValueError('RAM snapshots require page probe and1..32 unique frames in1..20000')
+            any(f<1 for f in args.ram_snapshot_frame)):
+        raise ValueError('RAM snapshots require page probe and 1..32 unique positive frames')
     if args.timer2_model!="default" and args.timer1_model!="octoshock-2.2.2":
         raise ValueError("timer2 model requires source timer1 model")
     if args.timer1_model!="default" and args.field_model!="octoshock-2.2.2-ntsc-raster":
@@ -187,6 +187,13 @@ def main():
     if clock_tape:
         paths['cd_source_clock_tape'] = Path(clock_tape['path'])
     identity = route_identity(paths["route"])
+    # The completion hook exits before the final return observer. Bind every
+    # enabled RAM capture to the exact declared number of observed returns.
+    ram_returns = identity['frames'] + args.neutral_tail - 1
+    if args.ram_page_probe and not 1 <= ram_returns <= 1000000:
+        raise ValueError('RAM capture requires 1..1000000 declared completed returns')
+    if any(frame > ram_returns for frame in args.ram_snapshot_frame):
+        raise ValueError('RAM snapshot exceeds the declared completed-return boundary')
     update_profile = None
     update_contexts = None
     context_values = None
@@ -328,6 +335,7 @@ p2_mode = "digital"
         selected_env['PSX_SOURCE_CPU_RETURN_PROBE']='1'
     if args.ram_page_probe:
         selected_env['PSX_SOURCE_RAM_PAGE_PROBE']='1'
+        selected_env['PSX_SOURCE_RAM_MAX_FRAMES']=str(ram_returns)
     if args.ram_snapshot_frame:
         selected_env['PSX_SOURCE_RAM_SNAPSHOT_FRAMES']=','.join(map(str,args.ram_snapshot_frame))
     if args.update_predictor != "gate":