diff --git a/locale/circuitpython.pot b/locale/circuitpython.pot
index 61fd0d0a6b..bd2d35398f 100644
--- a/locale/circuitpython.pot
+++ b/locale/circuitpython.pot
@@ -165,11 +165,15 @@ msgstr ""
 msgid "%q length must be >= %d"
 msgstr ""
 
-#: ports/raspberrypi/common-hal/picodvi/Framebuffer.c py/argcheck.c
+#: py/argcheck.c
 msgid "%q must be %d"
 msgstr ""
 
 #: py/argcheck.c shared-bindings/displayio/Bitmap.c
+#: shared-bindings/displayio/Display.c
+#: shared-bindings/framebufferio/FramebufferDisplay.c
+#: shared-bindings/is31fl3741/FrameBuffer.c
+#: shared-bindings/rgbmatrix/RGBMatrix.c
 msgid "%q must be %d-%d"
 msgstr ""
 
@@ -203,6 +207,7 @@ msgstr ""
 
 #: ports/raspberrypi/bindings/cyw43/__init__.c py/argcheck.c py/objexcept.c
 #: shared-bindings/canio/CAN.c shared-bindings/digitalio/Pull.c
+#: shared-module/synthio/Synthesizer.c
 msgid "%q must be of type %q or %q, not %q"
 msgstr ""
 
@@ -425,6 +430,7 @@ msgid "Address must be %d bytes long"
 msgstr ""
 
 #: ports/espressif/common-hal/memorymap/AddressRange.c
+#: ports/nrf/common-hal/memorymap/AddressRange.c
 msgid "Address range not allowed"
 msgstr ""
 
@@ -608,13 +614,6 @@ msgstr ""
 msgid "Both pins must support hardware interrupts"
 msgstr ""
 
-#: shared-bindings/displayio/Display.c
-#: shared-bindings/framebufferio/FramebufferDisplay.c
-#: shared-bindings/is31fl3741/FrameBuffer.c
-#: shared-bindings/rgbmatrix/RGBMatrix.c
-msgid "Brightness must be 0-1.0"
-msgstr ""
-
 #: shared-bindings/displayio/Display.c
 #: shared-bindings/framebufferio/FramebufferDisplay.c
 msgid "Brightness not adjustable"
@@ -927,11 +926,6 @@ msgstr ""
 msgid "EXTINT channel already in use"
 msgstr ""
 
-#: shared-module/synthio/MidiTrack.c
-#, c-format
-msgid "Error in MIDI stream at position %d"
-msgstr ""
-
 #: extmod/modure.c
 msgid "Error in regex"
 msgstr ""
@@ -1343,11 +1337,6 @@ msgstr ""
 msgid "Mapping must be a tuple"
 msgstr ""
 
-#: shared-module/displayio/Shape.c
-#, c-format
-msgid "Maximum x value when mirrored is %d"
-msgstr ""
-
 #: shared-bindings/audiobusio/PDMIn.c
 msgid "Microphone startup delay must be in range 0.0 to 1.0"
 msgstr ""
@@ -1441,6 +1430,10 @@ msgstr ""
 msgid "Nimble out of memory"
 msgstr ""
 
+#: ports/atmel-samd/common-hal/busio/UART.c
+msgid "No %q pin"
+msgstr ""
+
 #: ports/espressif/common-hal/_bleio/Characteristic.c
 #: ports/nrf/common-hal/_bleio/Characteristic.c
 msgid "No CCCD for this Characteristic"
@@ -1489,14 +1482,12 @@ msgstr ""
 msgid "No MOSI pin"
 msgstr ""
 
-#: ports/atmel-samd/common-hal/busio/UART.c
 #: ports/espressif/common-hal/busio/UART.c
 #: ports/mimxrt10xx/common-hal/busio/UART.c ports/nrf/common-hal/busio/UART.c
 #: ports/raspberrypi/common-hal/busio/UART.c ports/stm/common-hal/busio/UART.c
 msgid "No RX pin"
 msgstr ""
 
-#: ports/atmel-samd/common-hal/busio/UART.c
 #: ports/espressif/common-hal/busio/UART.c
 #: ports/mimxrt10xx/common-hal/busio/UART.c ports/nrf/common-hal/busio/UART.c
 #: ports/raspberrypi/common-hal/busio/UART.c ports/stm/common-hal/busio/UART.c
@@ -2123,8 +2114,8 @@ msgstr ""
 msgid "UART de-init"
 msgstr ""
 
-#: ports/atmel-samd/common-hal/busio/UART.c ports/cxd56/common-hal/busio/UART.c
-#: ports/espressif/common-hal/busio/UART.c ports/stm/common-hal/busio/UART.c
+#: ports/cxd56/common-hal/busio/UART.c ports/espressif/common-hal/busio/UART.c
+#: ports/stm/common-hal/busio/UART.c
 msgid "UART init"
 msgstr ""
 
@@ -4342,18 +4333,10 @@ msgstr ""
 msgid "wrong output type"
 msgstr ""
 
-#: shared-module/displayio/Shape.c
-msgid "x value out of bounds"
-msgstr ""
-
 #: ports/espressif/common-hal/audiobusio/__init__.c
 msgid "xTaskCreate failed"
 msgstr ""
 
-#: shared-module/displayio/Shape.c
-msgid "y value out of bounds"
-msgstr ""
-
 #: extmod/ulab/code/scipy/signal/signal.c
 msgid "zi must be an ndarray"
 msgstr ""
diff --git a/ports/atmel-samd/common-hal/busio/UART.c b/ports/atmel-samd/common-hal/busio/UART.c
index 280e8d10b6..92dbc9757e 100644
--- a/ports/atmel-samd/common-hal/busio/UART.c
+++ b/ports/atmel-samd/common-hal/busio/UART.c
@@ -241,7 +241,7 @@ void common_hal_busio_uart_construct(busio_uart_obj_t *self,
     }
 
     if (usart_async_init(usart_desc_p, sercom, self->buffer, self->buffer_length, NULL) != ERR_NONE) {
-        mp_raise_RuntimeError(translate("UART init"));
+        mp_raise_RuntimeError(NULL);
     }
 
     // usart_async_init() sets a number of defaults based on a prototypical SERCOM
@@ -396,7 +396,7 @@ void common_hal_busio_uart_deinit(busio_uart_obj_t *self) {
 // Read characters.
 size_t common_hal_busio_uart_read(busio_uart_obj_t *self, uint8_t *data, size_t len, int *errcode) {
     if (self->rx_pin == NO_PIN) {
-        mp_raise_ValueError(translate("No RX pin"));
+        mp_raise_ValueError_varg(translate("No %q pin"), MP_QSTR_rx);
     }
 
     // This assignment is only here because the usart_async routines take a *const argument.
@@ -453,7 +453,7 @@ size_t common_hal_busio_uart_read(busio_uart_obj_t *self, uint8_t *data, size_t
 // Write characters.
 size_t common_hal_busio_uart_write(busio_uart_obj_t *self, const uint8_t *data, size_t len, int *errcode) {
     if (self->tx_pin == NO_PIN) {
-        mp_raise_ValueError(translate("No TX pin"));
+        mp_raise_ValueError_varg(translate("No %q pin"), MP_QSTR_tx);
     }
 
     // This assignment is only here because the usart_async routines take a *const argument.
diff --git a/ports/unix/main.c b/ports/unix/main.c
index 5ebcf9193b..dcc1c68fe6 100644
--- a/ports/unix/main.c
+++ b/ports/unix/main.c
@@ -716,7 +716,7 @@ MP_NOINLINE int main_(int argc, char **argv) {
 }
 
 #if !MICROPY_VFS
-uint mp_import_stat(const char *path) {
+mp_import_stat_t mp_import_stat(const char *path) {
     struct stat st;
     if (stat(path, &st) == 0) {
         if (S_ISDIR(st.st_mode)) {
diff --git a/py/objarray.c b/py/objarray.c
index 518c3aba52..c4a9e7cec4 100644
--- a/py/objarray.c
+++ b/py/objarray.c
@@ -254,12 +254,14 @@ STATIC mp_obj_t memoryview_make_new(const mp_obj_type_t *type_in, size_t n_args,
 STATIC mp_obj_t memoryview_cast(const mp_obj_t self_in, const mp_obj_t typecode_in) {
     mp_obj_array_t *self = MP_OBJ_TO_PTR(self_in);
     const char *typecode = mp_obj_str_get_str(typecode_in);
-    size_t element_size = mp_binary_get_size('@', typecode[0], NULL);
-    size_t bytelen = self->len * mp_binary_get_size('@', self->typecode & ~MP_OBJ_ARRAY_TYPECODE_FLAG_RW, NULL);
-    if (bytelen % element_size != 0) {
+    size_t new_element_size = mp_binary_get_size('@', typecode[0], NULL);
+    size_t old_element_size = mp_binary_get_size('@', self->typecode & ~MP_OBJ_ARRAY_TYPECODE_FLAG_RW, NULL);
+    size_t bytelen = self->len * old_element_size;
+    if (bytelen % new_element_size != 0) {
         mp_raise_TypeError(MP_ERROR_TEXT("memoryview: length is not a multiple of itemsize"));
     }
-    mp_obj_array_t *result = MP_OBJ_TO_PTR(mp_obj_new_memoryview(*typecode, bytelen / element_size, self->items));
+    mp_obj_array_t *result = MP_OBJ_TO_PTR(mp_obj_new_memoryview(*typecode, bytelen / new_element_size, self->items));
+    result->memview_offset = (self->memview_offset * old_element_size) / new_element_size;
 
     // test if the object can be written to
     if (self->typecode & MP_OBJ_ARRAY_TYPECODE_FLAG_RW) {
diff --git a/tests/basics/memoryview_cast.py b/tests/basics/memoryview_cast.py
new file mode 100644
index 0000000000..24c04e8e5a
--- /dev/null
+++ b/tests/basics/memoryview_cast.py
@@ -0,0 +1,21 @@
+try:
+    memoryview(b'a').cast
+except:
+    print("SKIP")
+    raise SystemExit
+
+b = bytearray(range(16))
+
+def print_memview(mv):
+    print(", ".join(hex(v) for v in mv))
+
+mv = memoryview(b)
+print_memview(mv)
+print_memview(mv[4:])
+
+words = mv.cast("I")
+print_memview(words)
+print_memview(mv[4:].cast("I"))
+print_memview(words[1:])
+
+print_memview(words.cast("B"))