diff --git a/services/wolf.sh b/services/wolf.sh
index 3bda79f..8007e79 100644
--- a/services/wolf.sh
+++ b/services/wolf.sh
@@ -972,6 +972,27 @@ UDEV
         # <command> line in place across a real fix to it, since existing
         # was already "present" and the check never looked at whether its
         # content matched the current template.
+        #
+        # The <command> below does NOT use a literal "/bin/bash -c ..."
+        # string — confirmed against ES-DE's own source (FileData::findEmulator())
+        # and every real %INJECT%=...esprefix example in ES-DE's own shipped
+        # es_systems.xml (Dolphin/PrimeHack/Triforce/Supermodel): findEmulator()
+        # always runs against the <command> string's emulator token to decide
+        # "found" vs "not found", and %INJECT%=file is only ever paired with
+        # an %EMULATOR_X%/%CORE_X% placeholder in every real example — never
+        # with a literal path. Confirmed live: a literal "/bin/bash -c ..."
+        # after %INJECT%=%BASENAME%.esprefix made ES-DE log "Couldn't launch
+        # game, emulator not found" even though /bin/bash obviously exists —
+        # findEmulator() isn't falling back to a plain existence check on the
+        # next token there, it requires the %EMULATOR_X% resolution path.
+        # Fixed by giving ti99sim-sdl a real es_find_rules.xml entry (written
+        # below) and using %EMULATOR_TI99SIM%, matching the pattern every
+        # built-in standalone emulator uses. %STARTDIR%=%EMUDIR% (ES-DE's own
+        # "directory containing the resolved emulator binary" variable)
+        # replaces the old "cd /home/retro/Applications &&" shell prefix —
+        # ti99sim-sdl still needs its cwd to be its own install dir to find
+        # the console ROM (TI-994A.ctg) via a plain relative lookup, same as
+        # RetroPie's own ti99sim.sh does with its "pushd $md_inst" launch.
         python3 - "$_TI99_XML" << 'TI99XMLPY'
 import re, sys
 path = sys.argv[1]
@@ -986,7 +1007,7 @@ block = '''    <system>
         <fullname>Texas Instruments TI-99/4A</fullname>
         <path>%ROMPATH%/ti994a</path>
         <extension>.ctg .rpk .bin</extension>
-        <command>%INJECT%=%BASENAME%.esprefix /bin/bash -c "cd /home/retro/Applications && ./ti99sim-sdl --joystick1=1 '%ROM%'"</command>
+        <command>%INJECT%=%BASENAME%.esprefix %STARTDIR%=%EMUDIR% %EMULATOR_TI99SIM% --joystick1=1 %ROM%</command>
         <platform>ti99</platform>
         <theme>ti99</theme>
     </system>
@@ -997,6 +1018,39 @@ with open(path, 'w') as f:
 TI99XMLPY
         chown "$ACTUAL_USER:$ACTUAL_USER" "$_TI99_XML"
         log_success "TI-99/4A ES-DE system definition written/refreshed (roms/ti994a/, custom_systems/es_systems.xml)"
+
+        # es_find_rules.xml lives alongside custom es_systems.xml in the same
+        # custom_systems/ directory (confirmed against ES-DE's own
+        # USERGUIDE.md — "customize the find rules via the es_find_rules.xml
+        # file", same complement-not-replace logic as custom es_systems.xml).
+        # This is what makes %EMULATOR_TI99SIM% above resolvable at all —
+        # without it, ES-DE has no rule telling it what "TI99SIM" even means
+        # and would report the emulator as not found regardless of anything
+        # in es_systems.xml. Same strip-and-reappend idempotency as above, in
+        # case this file ever gains other custom emulator entries later.
+        local _TI99_RULES="$GAME_STORAGE_DIR/esde-custom-systems/es_find_rules.xml"
+        backup_if_exists "$_TI99_RULES"
+        python3 - "$_TI99_RULES" << 'TI99RULESPY'
+import re, sys
+path = sys.argv[1]
+try:
+    with open(path) as f:
+        content = f.read()
+except FileNotFoundError:
+    content = '<ruleList>\n</ruleList>\n'
+content = re.sub(r'[ \t]*<emulator name="TI99SIM">.*?</emulator>\s*\n?', '', content, flags=re.DOTALL)
+block = '''    <emulator name="TI99SIM">
+        <rule type="staticpath">
+            <entry>~/Applications/ti99sim-sdl</entry>
+        </rule>
+    </emulator>
+'''
+content = content.replace('</ruleList>', block + '</ruleList>')
+with open(path, 'w') as f:
+    f.write(content)
+TI99RULESPY
+        chown "$ACTUAL_USER:$ACTUAL_USER" "$_TI99_RULES"
+        log_success "TI-99/4A ES-DE find rule written/refreshed (custom_systems/es_find_rules.xml)"
         echo ""
         if [ ! -x "$GAME_STORAGE_DIR/emulators/ti99sim-sdl" ]; then
             # Build inside a container running the EXACT SAME image ES-DE