Work to optimize DatumTool: don't die on contents >30K (#731)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9834443..34fc00a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -19,7 +19,7 @@ The Maix Bit device has long been discouraged due to its poor-quality camera. St
 - Touchscreen test added in Tools for detection check
 - wbits for deflate-decompress window set to 10 bits to match KEF spec.
 - Remove "Reboot" option and status bar, when empty, from Login menu
-- Optimized Datum show: total pages are no longer visible, and navigation no longer wraps from the first page to the last or vice versa
+- Optimized Datum show: total pages are no longer visible, and navigation no longer wraps from the first page to the last or vice versa; better memory management and handling for large (~100K) files.
 - Enabled swipe up/down gestures on keypads, menus, and QR transcribe
 
 # Changelog 25.09.0 - September 2025
diff --git a/i18n/translations/de-DE.json b/i18n/translations/de-DE.json
index eabecb1..52b000f 100644
--- a/i18n/translations/de-DE.json
+++ b/i18n/translations/de-DE.json
@@ -99,6 +99,7 @@
     "Extended Public Key": "Öffentlicher Schlüssel",
     "Factory Settings": "Werkeinstellungen",
     "Failed gathering camera entropy": "Fehler beim Sammeln der Kameraentropie",
+    "Failed to convert": "Daten konnten nicht umgewandelt werden.",
     "Failed to decrypt": "Entschlüsselung fehlgeschlagen",
     "Failed to load": "Laden fehlgeschlagen.",
     "Failed to store mnemonic": "Mnemonic konnte nicht gespeichert werden",
diff --git a/i18n/translations/es-MX.json b/i18n/translations/es-MX.json
index dc3488e..c74700c 100644
--- a/i18n/translations/es-MX.json
+++ b/i18n/translations/es-MX.json
@@ -99,6 +99,7 @@
     "Extended Public Key": "Clave Pública Extendida",
     "Factory Settings": "Ajustes de Fábrica",
     "Failed gathering camera entropy": "Error al recopilar la entropía de la cámara",
+    "Failed to convert": "Error al convertir:",
     "Failed to decrypt": "Error al descifrar",
     "Failed to load": "Error al cargar",
     "Failed to store mnemonic": "No pudo almacenar mnemónico",
diff --git a/i18n/translations/fr-FR.json b/i18n/translations/fr-FR.json
index 320aa6c..d51dcf0 100644
--- a/i18n/translations/fr-FR.json
+++ b/i18n/translations/fr-FR.json
@@ -99,6 +99,7 @@
     "Extended Public Key": "Clé publique",
     "Factory Settings": "Paramètres d'usine",
     "Failed gathering camera entropy": "Échec de la collecte de l'entropie de la caméra",
+    "Failed to convert": "Échec de la conversion",
     "Failed to decrypt": "Échec du déchiffrement",
     "Failed to load": "Échec lors du chargement",
     "Failed to store mnemonic": "Échec du stockage mnémonique",
diff --git a/i18n/translations/ja-JP.json b/i18n/translations/ja-JP.json
index 8079272..fe8dc2a 100644
--- a/i18n/translations/ja-JP.json
+++ b/i18n/translations/ja-JP.json
@@ -99,6 +99,7 @@
     "Extended Public Key": "拡張公開キー",
     "Factory Settings": "初期設定",
     "Failed gathering camera entropy": "カメラエントロピーの収集に失敗しました",
+    "Failed to convert": "\"CRL変換に失敗\"",
     "Failed to decrypt": "復号化に失敗しました",
     "Failed to load": "ロードに失敗しました",
     "Failed to store mnemonic": "mnemonicの保存に失敗しました",
diff --git a/i18n/translations/ko-KR.json b/i18n/translations/ko-KR.json
index 919298e..49fd789 100644
--- a/i18n/translations/ko-KR.json
+++ b/i18n/translations/ko-KR.json
@@ -99,6 +99,7 @@
     "Extended Public Key": "XPUB 내보내기",
     "Factory Settings": "공장 초기 설정",
     "Failed gathering camera entropy": "카메라 엔트로피 수집 실패",
+    "Failed to convert": "변환 실패",
     "Failed to decrypt": "복호화에 실패했습니다",
     "Failed to load": "로드 실패",
     "Failed to store mnemonic": "니모닉을 저장하지 못했습니다",
diff --git a/i18n/translations/nl-NL.json b/i18n/translations/nl-NL.json
index ef8a6d6..9252f38 100644
--- a/i18n/translations/nl-NL.json
+++ b/i18n/translations/nl-NL.json
@@ -99,6 +99,7 @@
     "Extended Public Key": "Uitgebreide publieke sleutel",
     "Factory Settings": "Fabrieksinstellingen",
     "Failed gathering camera entropy": "Verzamelen van camera entropie mislukt",
+    "Failed to convert": "Kon niet geconverteerd worden",
     "Failed to decrypt": "Ontsleutelen is niet gelukt",
     "Failed to load": "Laden mislukt",
     "Failed to store mnemonic": "Geheugensteun opslaan is niet gelukt",
diff --git a/i18n/translations/pt-BR.json b/i18n/translations/pt-BR.json
index 069ea4f..28880cc 100644
--- a/i18n/translations/pt-BR.json
+++ b/i18n/translations/pt-BR.json
@@ -99,6 +99,7 @@
     "Extended Public Key": "Chave Pública Estendida",
     "Factory Settings": "Configurações de Fábrica",
     "Failed gathering camera entropy": "Falha ao capturar entropia da câmera",
+    "Failed to convert": "Falha ao converter",
     "Failed to decrypt": "Falha ao descriptografar",
     "Failed to load": "Falha ao carregar",
     "Failed to store mnemonic": "Falha ao armazenar mnemônico",
diff --git a/i18n/translations/ru-RU.json b/i18n/translations/ru-RU.json
index 34723a5..58ef802 100644
--- a/i18n/translations/ru-RU.json
+++ b/i18n/translations/ru-RU.json
@@ -99,6 +99,7 @@
     "Extended Public Key": "Расширенный Публичный Ключ",
     "Factory Settings": "Заводские Настройки",
     "Failed gathering camera entropy": "Не удалось собрать энтропию камеры",
+    "Failed to convert": "Преобразование не выполнено.",
     "Failed to decrypt": "Не удалось расшифровать",
     "Failed to load": "Не удалось ничего загрузить",
     "Failed to store mnemonic": "Не удалось сохранить мнемонику",
diff --git a/i18n/translations/tr-TR.json b/i18n/translations/tr-TR.json
index 715dfef..c0bf4cd 100644
--- a/i18n/translations/tr-TR.json
+++ b/i18n/translations/tr-TR.json
@@ -99,6 +99,7 @@
     "Extended Public Key": "Genişletilmiş Public Key",
     "Factory Settings": "Fabrika Ayarları",
     "Failed gathering camera entropy": "Kamera entropisi toplanamadı",
+    "Failed to convert": "Veri dönüştürme başarısız.",
     "Failed to decrypt": "Şifre çözme başarısız",
     "Failed to load": "Yüklenemedi",
     "Failed to store mnemonic": "Mnemonic depolama başarısız",
diff --git a/i18n/translations/vi-VN.json b/i18n/translations/vi-VN.json
index da7e97b..9ee3a80 100644
--- a/i18n/translations/vi-VN.json
+++ b/i18n/translations/vi-VN.json
@@ -99,6 +99,7 @@
     "Extended Public Key": "Khóa công cộng",
     "Factory Settings": "Cài đặt Gốc",
     "Failed gathering camera entropy": "Không thể thu thập entropy của máy ảnh",
+    "Failed to convert": "Không thể chuyển đổi",
     "Failed to decrypt": "Không giải mã được",
     "Failed to load": "Tải thất bại",
     "Failed to store mnemonic": "Không lưu trữ Mnemonic được",
diff --git a/i18n/translations/zh-CN.json b/i18n/translations/zh-CN.json
index 2eb4f33..924fb1b 100644
--- a/i18n/translations/zh-CN.json
+++ b/i18n/translations/zh-CN.json
@@ -99,6 +99,7 @@
     "Extended Public Key": "扩展公钥",
     "Factory Settings": "出厂设置",
     "Failed gathering camera entropy": "收集摄像头熵失败",
+    "Failed to convert": "转换失败.",
     "Failed to decrypt": "解密失败",
     "Failed to load": "加载失败",
     "Failed to store mnemonic": "存储助记词失败",
diff --git a/src/krux/pages/datum_tool.py b/src/krux/pages/datum_tool.py
index 97a1d27..95663db 100644
--- a/src/krux/pages/datum_tool.py
+++ b/src/krux/pages/datum_tool.py
@@ -20,6 +20,8 @@
 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 # THE SOFTWARE.
 
+import gc
+from krux.wdt import wdt
 from . import (
     Page,
     Menu,
@@ -70,6 +72,8 @@ DATUM_BBQR_TYPES = {
 }
 
 STATIC_QR_MAX_SIZE = 4  # version 5 - 37x37
+SUFFICIENT_SAMPLE_SIZE = 512  # to truncate large contents for sampling
+SLOW_ENCODING_MAX_SIZE = 2**14  # base43,base58,bech32 not offered above this size
 
 
 def urobj_to_data(ur_obj):
@@ -129,17 +133,17 @@ def convert_encoding(contents, conversion):
     return None
 
 
-def identify_datum(data):
+def identify_datum(data, encodings=None):
     """Determine which "datum" type this is; ie: PSBT, XPUB, DESC, ADDR"""
 
     # TODO: more samples and fewer false-positives
-
     datum = None
     if isinstance(data, bytes):
         if data[:5] == b"psbt\xff":
             datum = DATUM_PSBT
     elif len(data) > 33:
-        encodings = detect_encodings(data)
+        if encodings is None:
+            encodings = detect_encodings(data)
 
         if data[:1] in "xyzYZtuvUV" and data[1:4] == "pub" and 58 in encodings:
             datum = DATUM_XPUB
@@ -153,7 +157,7 @@ def identify_datum(data):
             datum = DATUM_DESCRIPTOR
         elif (data[:1] in ("1", "3", "n", "2", "m") and 58 in encodings) or (
             data[:4].lower() in ("bc1p", "bc1q", "tb1p", "tb1q")
-            and "bech32" in [x.lower()[:6] for x in encodings]
+            and "bech32" in [x.lower()[:6] for x in encodings if isinstance(x, str)]
         ):
             datum = DATUM_ADDRESS
 
@@ -177,14 +181,15 @@ def detect_encodings(str_data, verify=True):
     if not isinstance(str_data, str):
         raise TypeError("detect_encodings() expected str")
 
-    # get min and max characters (sorted by ordinal value),
-    # check most restrictive encodings first
+    str_len = len(str_data)
 
-    min_chr = min(str_data)
-    max_chr = max(str_data)
+    # get min and max characters (sorted by ordinal value)
+    # then check most restrictive encodings first
+    min_chr = min(str_data[:SUFFICIENT_SAMPLE_SIZE])
+    max_chr = max(str_data[:SUFFICIENT_SAMPLE_SIZE])
 
     # might it be hex
-    if len(str_data) % 2 == 0 and "0" <= min_chr:
+    if str_len % 2 == 0 and "0" <= min_chr:
         if max_chr <= "F":
             if verify:
                 try:
@@ -216,11 +221,12 @@ def detect_encodings(str_data, verify=True):
             encodings.append(32)
 
     # might it be bech32
-    if "0" <= min_chr:
+    if str_len <= SLOW_ENCODING_MAX_SIZE and "0" <= min_chr:
         encoding = None
         if max_chr <= "Z":
             if verify:
                 encoding, _, _ = bech32_decode(str_data)
+                wdt.feed()
             if encoding == Encoding.BECH32:
                 encodings.append("BECH32")
             elif encoding == Encoding.BECH32M:
@@ -234,10 +240,11 @@ def detect_encodings(str_data, verify=True):
                 encodings.append("bech32m")
 
     # might it be base43
-    if "$" <= min_chr and max_chr <= "Z":
+    if str_len <= SLOW_ENCODING_MAX_SIZE and "$" <= min_chr and max_chr <= "Z":
         if verify:
             try:
                 base_decode(str_data, 43)
+                wdt.feed()
                 encodings.append(43)
             except:
                 pass
@@ -245,10 +252,11 @@ def detect_encodings(str_data, verify=True):
             encodings.append(43)
 
     # might it be base58
-    if "1" <= min_chr and max_chr <= "z":
+    if str_len <= SLOW_ENCODING_MAX_SIZE and "1" <= min_chr and max_chr <= "z":
         if verify:
             try:
                 base_decode(str_data, 58)
+                wdt.feed()
                 encodings.append(58)
             except:
                 pass
@@ -263,6 +271,7 @@ def detect_encodings(str_data, verify=True):
                 as_bytes = base_decode(str_data, 64)
                 if base_encode(as_bytes, 64) == str_data:
                     encodings.append(64)
+                del as_bytes
             except:
                 pass
         else:
@@ -279,6 +288,8 @@ def detect_encodings(str_data, verify=True):
     # assume utf8
     encodings.append("utf8")
 
+    gc.collect()
+
     return encodings
 
 
@@ -353,7 +364,6 @@ class DatumToolMenu(Page):
         from .utils import Utils
 
         if not self.has_sd_card():
-            self.ctx.display.clear()
             self.flash_error(t("SD card not detected."))
             return MENU_CONTINUE
 
@@ -366,6 +376,9 @@ class DatumToolMenu(Page):
         if not contents:
             return MENU_CONTINUE
 
+        self.ctx.display.clear()
+        self.ctx.display.draw_centered_text(t("Processing…"))
+
         # utils.load_file() always returns binary
         try:
             contents = contents.decode()
@@ -411,9 +424,9 @@ class DatumTool(Page):
 
         seedqrview_thresh = QR_CAPACITY_BYTE[STATIC_QR_MAX_SIZE]
         if not isinstance(self.contents, bytes):
-            if all(c.isdigit() for c in self.contents):
+            if all(c.isdigit() for c in self.contents[:SUFFICIENT_SAMPLE_SIZE]):
                 seedqrview_thresh = QR_CAPACITY_NUMERIC[STATIC_QR_MAX_SIZE]
-            elif all(is_alnum(c) for c in self.contents):
+            elif all(is_alnum(c) for c in self.contents[:SUFFICIENT_SAMPLE_SIZE]):
                 seedqrview_thresh = QR_CAPACITY_ALPHANUMERIC[STATIC_QR_MAX_SIZE]
 
         if len(self.contents) <= seedqrview_thresh:
@@ -451,10 +464,10 @@ class DatumTool(Page):
         else:
             from ..qr import FORMAT_NONE, FORMAT_PMOFN, FORMAT_BBQR, FORMAT_UR
 
-            menu_opts = [
-                (t("Static"), (FORMAT_NONE,)),
-                (t("Part M of N"), (FORMAT_PMOFN,)),
-            ]
+            menu_opts = []
+            if len(self.contents) <= seedqrview_thresh * 4:
+                menu_opts.append((t("Static"), (FORMAT_NONE,)))
+            menu_opts.append((t("Part M of N"), (FORMAT_PMOFN,)))
 
             if self.datum in DATUM_BBQR_TYPES:
                 menu_opts.extend(
@@ -464,7 +477,7 @@ class DatumTool(Page):
                     ]
                 )
 
-            curr_datum = identify_datum(self.contents)
+            curr_datum = identify_datum(self.contents, self.encodings)
             if curr_datum:
                 if curr_datum in DATUM_UR_TYPES:
                     menu_opts.extend(
@@ -553,12 +566,13 @@ class DatumTool(Page):
             ),
         ]
         if preview:
+            preview_contents = self.contents[:SUFFICIENT_SAMPLE_SIZE]
             parts.append(
                 self.fit_to_line(
                     (
-                        '"' + self.contents + '"'
-                        if isinstance(self.contents, str)
-                        else "0x" + hexlify(self.contents).decode()
+                        '"' + preview_contents + '"'
+                        if isinstance(preview_contents, str)
+                        else "0x" + hexlify(preview_contents).decode()
                     ),
                     crop_middle=False,
                 )
@@ -574,6 +588,7 @@ class DatumTool(Page):
     def _show_contents(self):
         """Displays infobox and contents"""
         from binascii import hexlify
+        from ..settings import ELLIPSIS
         from ..kboard import kboard
 
         page_indicator = "p.%d"
@@ -583,12 +598,7 @@ class DatumTool(Page):
             if not kboard.is_m5stickv
             else (self.ctx.display.width() % FONT_WIDTH) // 2
         )
-        contents = (
-            self.contents
-            if isinstance(self.contents, str)
-            else hexlify(self.contents).decode()
-        )
-        content_len = len(contents)
+        content_len = len(self.contents)
 
         def _update_infobox(curr_page):
             info_len = self._info_box(
@@ -603,9 +613,17 @@ class DatumTool(Page):
 
         while True:
             info_len, max_lines = _update_infobox(curr_page + 1)
-            lines, endpos = self.ctx.display.to_lines_endpos(
-                contents[start_index:], max_lines
-            )
+            chars_per_page = self.ctx.display.width() // FONT_WIDTH * max_lines
+            contents = self.contents[start_index : start_index + chars_per_page + 1]
+            if isinstance(contents, bytes):
+                contents = hexlify(contents).decode()[: chars_per_page + 1]
+            lines, endpos = self.ctx.display.to_lines_endpos(contents, max_lines)
+            if isinstance(self.contents, bytes):
+                if endpos % 2:
+                    endpos -= 1
+                    if lines[-1][-1] == ELLIPSIS:
+                        lines[-1] = lines[-1][:-2] + ELLIPSIS * 2
+                endpos = endpos // 2
             endpos += start_index
             if pages[-1] < endpos < content_len:
                 pages.append(endpos)
@@ -642,6 +660,8 @@ class DatumTool(Page):
             try:
                 as_str = self.contents.decode()
                 suggestion = str(detect_encodings(as_str, False)[0])
+                del as_str
+                gc.collect()
                 if suggestion != "utf8":
                     suggestion = suggestion + "_via_utf8"
                 self.encodings = [suggestion + "?"]
@@ -664,12 +684,13 @@ class DatumTool(Page):
             self.encodings = detect_encodings(self.contents)
 
             # does it look like a 12 or 24 word mnemonic / Mnemonic QR?
-            if len(self.contents.split()) in (12, 24):
+            if len(self.contents[:256].split()) in (12, 24):
                 self.sensitive = True
 
             # does it look like a 12 or 24 word decimal mnemonic / StandadardSeedQR?
-            elif len(set((x in "0123456789" for x in self.contents))) == 1 and (
+            elif (
                 len(self.contents) in (12 * 4, 24 * 4)
+                and len(set((x in "0123456789" for x in self.contents))) == 1
             ):
                 self.sensitive = True
 
@@ -681,7 +702,7 @@ class DatumTool(Page):
 
         # datum
         if not self.datum:
-            self.datum = identify_datum(self.contents)
+            self.datum = identify_datum(self.contents, self.encodings)
 
     def _decrypt_as_kef_envelope(self):
         """Assuming self.contents are encrypted, offer to decrypt"""
@@ -726,7 +747,9 @@ class DatumTool(Page):
                 else:
                     menu.append((t("to hex"), lambda: "hex"))
                 menu.append((t("to base32"), lambda: 32))
-                menu.append((t("to base43"), lambda: 43))
+                if len(self.contents) <= SLOW_ENCODING_MAX_SIZE * 5.42 / 8:
+                    # 5.42 slightly less than log2(43); adjusts for base43 bloat
+                    menu.append((t("to base43"), lambda: 43))
                 menu.append((t("to base64"), lambda: 64))
                 try:
                     self.contents.decode()
@@ -770,6 +793,8 @@ class DatumTool(Page):
         """allows to view, convert, encrypt/decrypt, and export short str/bytes contents"""
         from .encryption_ui import KEFEnvelope
 
+        gc.collect()
+
         kvargs = {
             "try_decrypt": try_decrypt,
             "offer_convert": offer_convert,
@@ -806,6 +831,9 @@ class DatumTool(Page):
             # if user chose to exit
             return MENU_CONTINUE
 
+        self.ctx.display.clear()
+        self.ctx.display.draw_centered_text(t("Processing…"))
+
         if status == "show":
             # if user wants to view data
             self._show_contents()
@@ -817,11 +845,21 @@ class DatumTool(Page):
             kvargs["offer_convert"] = False
         elif status in ("undo", "hex", "HEX", 32, 43, 64, "utf8", "shift_case"):
             # if user chose a particular conversion
+            undo = False
             if status == "undo":
+                undo = True
                 status = self.history.pop()
+            new_contents = convert_encoding(self.contents, status)
+            if new_contents is not None:
+                self.contents = new_contents
+                if not undo:
+                    self.history.append(status)
+                del new_contents
             else:
-                self.history.append(status)
-            self.contents = convert_encoding(self.contents, status)
+                if undo:
+                    self.history.append(status)
+                self.flash_error(t("Failed to convert"))
+
         elif status == "encrypt":
             # if user chose to encrypt
             kef = KEFEnvelope(self.ctx)
diff --git a/src/krux/translations/__init__.py b/src/krux/translations/__init__.py
index ff5987c..0b38b7c 100644
--- a/src/krux/translations/__init__.py
+++ b/src/krux/translations/__init__.py
@@ -133,6 +133,7 @@ ref_array = [
     1711312434,
     3981762528,
     44497516,
+    572371442,
     383371114,
     3215045701,
     2946146830,
diff --git a/src/krux/translations/de.py b/src/krux/translations/de.py
index 9c131ad..9970e8a 100644
--- a/src/krux/translations/de.py
+++ b/src/krux/translations/de.py
@@ -121,6 +121,7 @@ translation_array = [
     "Öffentlicher Schlüssel",
     "Werkeinstellungen",
     "Fehler beim Sammeln der Kameraentropie",
+    "Daten konnten nicht umgewandelt werden.",
     "Entschlüsselung fehlgeschlagen",
     "Laden fehlgeschlagen.",
     "Mnemonic konnte nicht gespeichert werden",
diff --git a/src/krux/translations/es.py b/src/krux/translations/es.py
index 63cf180..114f3ba 100644
--- a/src/krux/translations/es.py
+++ b/src/krux/translations/es.py
@@ -121,6 +121,7 @@ translation_array = [
     "Clave Pública Extendida",
     "Ajustes de Fábrica",
     "Error al recopilar la entropía de la cámara",
+    "Error al convertir:",
     "Error al descifrar",
     "Error al cargar",
     "No pudo almacenar mnemónico",
diff --git a/src/krux/translations/fr.py b/src/krux/translations/fr.py
index 1c4f858..1358e45 100644
--- a/src/krux/translations/fr.py
+++ b/src/krux/translations/fr.py
@@ -121,6 +121,7 @@ translation_array = [
     "Clé publique",
     "Paramètres d'usine",
     "Échec de la collecte de l'entropie de la caméra",
+    "Échec de la conversion",
     "Échec du déchiffrement",
     "Échec lors du chargement",
     "Échec du stockage mnémonique",
diff --git a/src/krux/translations/ja.py b/src/krux/translations/ja.py
index 7b0bb7e..0b01479 100644
--- a/src/krux/translations/ja.py
+++ b/src/krux/translations/ja.py
@@ -121,6 +121,7 @@ translation_array = [
     "拡張公開キー",
     "初期設定",
     "カメラエントロピーの収集に失敗しました",
+    '"CRL変換に失敗"',
     "復号化に失敗しました",
     "ロードに失敗しました",
     "mnemonicの保存に失敗しました",
diff --git a/src/krux/translations/ko.py b/src/krux/translations/ko.py
index cacfb18..e08303a 100644
--- a/src/krux/translations/ko.py
+++ b/src/krux/translations/ko.py
@@ -121,6 +121,7 @@ translation_array = [
     "XPUB 내보내기",
     "공장 초기 설정",
     "카메라 엔트로피 수집 실패",
+    "변환 실패",
     "복호화에 실패했습니다",
     "로드 실패",
     "니모닉을 저장하지 못했습니다",
diff --git a/src/krux/translations/nl.py b/src/krux/translations/nl.py
index adec580..2f6ce75 100644
--- a/src/krux/translations/nl.py
+++ b/src/krux/translations/nl.py
@@ -121,6 +121,7 @@ translation_array = [
     "Uitgebreide publieke sleutel",
     "Fabrieksinstellingen",
     "Verzamelen van camera entropie mislukt",
+    "Kon niet geconverteerd worden",
     "Ontsleutelen is niet gelukt",
     "Laden mislukt",
     "Geheugensteun opslaan is niet gelukt",
diff --git a/src/krux/translations/pt.py b/src/krux/translations/pt.py
index 106e96f..5bd8ed4 100644
--- a/src/krux/translations/pt.py
+++ b/src/krux/translations/pt.py
@@ -121,6 +121,7 @@ translation_array = [
     "Chave Pública Estendida",
     "Configurações de Fábrica",
     "Falha ao capturar entropia da câmera",
+    "Falha ao converter",
     "Falha ao descriptografar",
     "Falha ao carregar",
     "Falha ao armazenar mnemônico",
diff --git a/src/krux/translations/ru.py b/src/krux/translations/ru.py
index 78167ef..b90a392 100644
--- a/src/krux/translations/ru.py
+++ b/src/krux/translations/ru.py
@@ -121,6 +121,7 @@ translation_array = [
     "Расширенный Публичный Ключ",
     "Заводские Настройки",
     "Не удалось собрать энтропию камеры",
+    "Преобразование не выполнено.",
     "Не удалось расшифровать",
     "Не удалось ничего загрузить",
     "Не удалось сохранить мнемонику",
diff --git a/src/krux/translations/tr.py b/src/krux/translations/tr.py
index 21c1f69..d485662 100644
--- a/src/krux/translations/tr.py
+++ b/src/krux/translations/tr.py
@@ -121,6 +121,7 @@ translation_array = [
     "Genişletilmiş Public Key",
     "Fabrika Ayarları",
     "Kamera entropisi toplanamadı",
+    "Veri dönüştürme başarısız.",
     "Şifre çözme başarısız",
     "Yüklenemedi",
     "Mnemonic depolama başarısız",
diff --git a/src/krux/translations/vi.py b/src/krux/translations/vi.py
index bb098ab..2eb51c6 100644
--- a/src/krux/translations/vi.py
+++ b/src/krux/translations/vi.py
@@ -121,6 +121,7 @@ translation_array = [
     "Khóa công cộng",
     "Cài đặt Gốc",
     "Không thể thu thập entropy của máy ảnh",
+    "Không thể chuyển đổi",
     "Không giải mã được",
     "Tải thất bại",
     "Không lưu trữ Mnemonic được",
diff --git a/src/krux/translations/zh.py b/src/krux/translations/zh.py
index 993f874..babb8bd 100644
--- a/src/krux/translations/zh.py
+++ b/src/krux/translations/zh.py
@@ -121,6 +121,7 @@ translation_array = [
     "扩展公钥",
     "出厂设置",
     "收集摄像头熵失败",
+    "转换失败.",
     "解密失败",
     "加载失败",
     "存储助记词失败",
diff --git a/tests/pages/test_datum_tool.py b/tests/pages/test_datum_tool.py
index 298972d..0f9912c 100644
--- a/tests/pages/test_datum_tool.py
+++ b/tests/pages/test_datum_tool.py
@@ -1066,6 +1066,7 @@ def test_datumtool_view_contents(m5stickv, mocker, mock_file_operations):
 
 def test_datumtool_view_contents_multi_page(m5stickv, mocker):
     """simply to cover building of `pages` index, moving to `next page`, and `prev page`"""
+    from binascii import hexlify
     from krux.pages.datum_tool import DatumTool
     from krux.input import PRESSED, BUTTON_ENTER, BUTTON_PAGE, BUTTON_PAGE_PREV
 
@@ -1092,6 +1093,71 @@ def test_datumtool_view_contents_multi_page(m5stickv, mocker):
     page.view_contents()
     assert ctx.input.wait_for_button.call_count == len(BTN_SEQUENCE)
 
+    # call with bytes that will span more than one page
+    BTN_SEQUENCE = [
+        BUTTON_ENTER,  # go Show Datum
+        BUTTON_ENTER,  # escape Show Datum
+        BUTTON_PAGE_PREV,  # to Back
+        BUTTON_ENTER,  # go Back
+    ]
+    ctx = create_ctx(mocker, BTN_SEQUENCE)
+    ctx.display.to_lines_endpos = mocker.MagicMock(
+        side_effect=[
+            (
+                [hexlify(b"8 bytes.").decode() for _ in range(15)]
+                + ["382062797465732…"],
+                127,
+            ),
+            ([hexlify(b".8 bytes").decode() for _ in range(4)] + ["2e"], 33),
+        ]
+    )
+    page = DatumTool(ctx)
+    page.contents = b"8 bytes." * 20
+    page.title = "title"
+    page.view_contents()
+    assert ctx.input.wait_for_button.call_count == len(BTN_SEQUENCE)
+
+
+def test_datumtool_view_contents_convert_failure(mocker, m5stickv):
+    """Contents cannot always be converted (ie: mem-alloc-err); flash_error"""
+    from krux.pages.datum_tool import DatumTool
+    from krux.input import BUTTON_ENTER, BUTTON_PAGE, BUTTON_PAGE_PREV
+
+    # mock failure in convert_encoding so it returns None
+    mocker.patch(
+        "binascii.unhexlify",
+        new=mocker.MagicMock(
+            side_effect=[
+                b"\xde\xad\xbe\xef",  # first call to unhexlify works, during detect_encoding()
+                Exception(
+                    "mocked failure"
+                ),  # second call fails, during convert_encoding()
+            ]
+        ),
+    )
+    from binascii import unhexlify
+
+    # call with bytes to be hexlified that will fail to convert via mocked unhexlify
+    BTN_SEQUENCE = (
+        BUTTON_ENTER,  # go Convert
+        BUTTON_ENTER,  # go "to hex"
+        BUTTON_ENTER,  # go "from hex", mocked failure
+        BUTTON_PAGE_PREV,  # to Done Converting
+        BUTTON_ENTER,  # go Done Converting
+        BUTTON_PAGE_PREV,  # to Back
+        BUTTON_ENTER,  # go Back
+    )
+    ctx = create_ctx(mocker, BTN_SEQUENCE)
+    page = DatumTool(ctx)
+    page.contents = b"\xde\xad\xbe\xef"
+    page.title = "title"
+    page.view_contents()
+    assert ctx.input.wait_for_button.call_count == len(BTN_SEQUENCE)
+    assert ctx.display.flash_text.call_count == 1
+    ctx.display.flash_text.assert_called_with(
+        "Failed to convert", 248, 2000, highlight_prefix=""
+    )
+
 
 def test_datumtool_show_contents_button_turbo(mocker, m5stickv):
     from krux.pages.datum_tool import DatumTool