diff --git a/.cspell.dict/cpython.txt b/.cspell.dict/cpython.txt
index 00fd7f024..c0d007a90 100644
--- a/.cspell.dict/cpython.txt
+++ b/.cspell.dict/cpython.txt
@@ -12,6 +12,7 @@ baseinfo
 basetype
 binop
 boolop
+BUFMAX
 BUILDSTDLIB
 bxor
 byteswap
@@ -33,6 +34,8 @@ cmpop
 codedepth
 constevaluator
 CODEUNIT
+CONIN
+CONOUT
 CONVFUNC
 convparam
 copyslot
@@ -105,6 +108,7 @@ metavars
 miscompiles
 mult
 multibytecodec
+nameobj
 nameop
 nconsts
 newargs
@@ -160,6 +164,7 @@ SETREF
 setresult
 setslice
 SLOTDEFINED
+SMALLBUF
 SOABI
 SSLEOF
 stackdepth
@@ -174,6 +179,7 @@ subscr
 sval
 swappedbytes
 templatelib
+testconsole
 ticketer
 tmptype
 tok_oldval
@@ -199,6 +205,7 @@ wbits
 weakreflist
 weakrefobject
 webpki
+winconsoleio
 withitem
 withs
 xstat
diff --git a/Lib/test/test_fileio.py b/Lib/test/test_fileio.py
index ac57e71c4..4f195cf04 100644
--- a/Lib/test/test_fileio.py
+++ b/Lib/test/test_fileio.py
@@ -508,10 +508,6 @@ class PyAutoFileTests(AutoFileTests, unittest.TestCase):
     FileIO = _pyio.FileIO
     modulename = '_pyio'
 
-    @unittest.expectedFailureIfWindows('TODO: RUSTPYTHON; _blksize mismatch on Windows')
-    def testBlksize(self):
-        return super().testBlksize()
-
 
 class OtherFileTests:
 
diff --git a/Lib/test/test_winconsoleio.py b/Lib/test/test_winconsoleio.py
new file mode 100644
index 000000000..1bae884ed
--- /dev/null
+++ b/Lib/test/test_winconsoleio.py
@@ -0,0 +1,244 @@
+'''Tests for WindowsConsoleIO
+'''
+
+import io
+import os
+import sys
+import tempfile
+import unittest
+from test.support import os_helper, requires_resource
+
+if sys.platform != 'win32':
+    raise unittest.SkipTest("test only relevant on win32")
+
+from _testconsole import write_input
+
+ConIO = io._WindowsConsoleIO
+
+class WindowsConsoleIOTests(unittest.TestCase):
+    def test_abc(self):
+        self.assertIsSubclass(ConIO, io.RawIOBase)
+        self.assertNotIsSubclass(ConIO, io.BufferedIOBase)
+        self.assertNotIsSubclass(ConIO, io.TextIOBase)
+
+    def test_open_fd(self):
+        self.assertRaisesRegex(ValueError,
+            "negative file descriptor", ConIO, -1)
+
+        with tempfile.TemporaryFile() as tmpfile:
+            fd = tmpfile.fileno()
+            # Windows 10: "Cannot open non-console file"
+            # Earlier: "Cannot open console output buffer for reading"
+            self.assertRaisesRegex(ValueError,
+                "Cannot open (console|non-console file)", ConIO, fd)
+
+        try:
+            f = ConIO(0)
+        except ValueError:
+            # cannot open console because it's not a real console
+            pass
+        else:
+            self.assertTrue(f.readable())
+            self.assertFalse(f.writable())
+            self.assertEqual(0, f.fileno())
+            f.close()   # multiple close should not crash
+            f.close()
+            with self.assertWarns(RuntimeWarning):
+                with ConIO(False):
+                    pass
+
+        try:
+            f = ConIO(1, 'w')
+        except ValueError:
+            # cannot open console because it's not a real console
+            pass
+        else:
+            self.assertFalse(f.readable())
+            self.assertTrue(f.writable())
+            self.assertEqual(1, f.fileno())
+            f.close()
+            f.close()
+            with self.assertWarns(RuntimeWarning):
+                with ConIO(False):
+                    pass
+
+        try:
+            f = ConIO(2, 'w')
+        except ValueError:
+            # cannot open console because it's not a real console
+            pass
+        else:
+            self.assertFalse(f.readable())
+            self.assertTrue(f.writable())
+            self.assertEqual(2, f.fileno())
+            f.close()
+            f.close()
+
+    def test_open_name(self):
+        self.assertRaises(ValueError, ConIO, sys.executable)
+
+        f = ConIO("CON")
+        self.assertTrue(f.readable())
+        self.assertFalse(f.writable())
+        self.assertIsNotNone(f.fileno())
+        f.close()   # multiple close should not crash
+        f.close()
+
+        f = ConIO('CONIN$')
+        self.assertTrue(f.readable())
+        self.assertFalse(f.writable())
+        self.assertIsNotNone(f.fileno())
+        f.close()
+        f.close()
+
+        f = ConIO('CONOUT$', 'w')
+        self.assertFalse(f.readable())
+        self.assertTrue(f.writable())
+        self.assertIsNotNone(f.fileno())
+        f.close()
+        f.close()
+
+        # bpo-45354: Windows 11 changed MS-DOS device name handling
+        if sys.getwindowsversion()[:3] < (10, 0, 22000):
+            f = open('C:/con', 'rb', buffering=0)
+            self.assertIsInstance(f, ConIO)
+            f.close()
+
+    def test_subclass_repr(self):
+        class TestSubclass(ConIO):
+            pass
+
+        f = TestSubclass("CON")
+        with f:
+            self.assertIn(TestSubclass.__name__, repr(f))
+
+        self.assertIn(TestSubclass.__name__, repr(f))
+
+    @unittest.skipIf(sys.getwindowsversion()[:2] <= (6, 1),
+        "test does not work on Windows 7 and earlier")
+    def test_conin_conout_names(self):
+        f = open(r'\\.\conin$', 'rb', buffering=0)
+        self.assertIsInstance(f, ConIO)
+        f.close()
+
+        f = open('//?/conout$', 'wb', buffering=0)
+        self.assertIsInstance(f, ConIO)
+        f.close()
+
+    def test_conout_path(self):
+        temp_path = tempfile.mkdtemp()
+        self.addCleanup(os_helper.rmtree, temp_path)
+
+        conout_path = os.path.join(temp_path, 'CONOUT$')
+
+        with open(conout_path, 'wb', buffering=0) as f:
+            # bpo-45354: Windows 11 changed MS-DOS device name handling
+            if (6, 1) < sys.getwindowsversion()[:3] < (10, 0, 22000):
+                self.assertIsInstance(f, ConIO)
+            else:
+                self.assertNotIsInstance(f, ConIO)
+
+    def test_write_empty_data(self):
+        with ConIO('CONOUT$', 'w') as f:
+            self.assertEqual(f.write(b''), 0)
+
+    @requires_resource('console')
+    def test_write(self):
+        testcases = []
+        with ConIO('CONOUT$', 'w') as f:
+            for a in [
+                b'',
+                b'abc',
+                b'\xc2\xa7\xe2\x98\x83\xf0\x9f\x90\x8d',
+                b'\xff'*10,
+            ]:
+                for b in b'\xc2\xa7', b'\xe2\x98\x83', b'\xf0\x9f\x90\x8d':
+                    testcases.append(a + b)
+                    for i in range(1, len(b)):
+                        data = a + b[:i]
+                        testcases.append(data + b'z')
+                        testcases.append(data + b'\xff')
+                        # incomplete multibyte sequence
+                        with self.subTest(data=data):
+                            self.assertEqual(f.write(data), len(a))
+            for data in testcases:
+                with self.subTest(data=data):
+                    self.assertEqual(f.write(data), len(data))
+
+    def assertStdinRoundTrip(self, text):
+        stdin = open('CONIN$', 'r')
+        old_stdin = sys.stdin
+        try:
+            sys.stdin = stdin
+            write_input(
+                stdin.buffer.raw,
+                (text + '\r\n').encode('utf-16-le', 'surrogatepass')
+            )
+            actual = input()
+        finally:
+            sys.stdin = old_stdin
+        self.assertEqual(actual, text)
+
+    @requires_resource('console')
+    def test_input(self):
+        # ASCII
+        self.assertStdinRoundTrip('abc123')
+        # Non-ASCII
+        self.assertStdinRoundTrip('ϼўТλФЙ')
+        # Combining characters
+        self.assertStdinRoundTrip('A͏B ﬖ̳AA̝')
+
+    # bpo-38325
+    @unittest.skipIf(True, "Handling Non-BMP characters is broken")
+    def test_input_nonbmp(self):
+        # Non-BMP
+        self.assertStdinRoundTrip('\U00100000\U0010ffff\U0010fffd')
+
+    @requires_resource('console')
+    def test_partial_reads(self):
+        # Test that reading less than 1 full character works when stdin
+        # contains multibyte UTF-8 sequences
+        source = 'ϼўТλФЙ\r\n'.encode('utf-16-le')
+        expected = 'ϼўТλФЙ\r\n'.encode('utf-8')
+        for read_count in range(1, 16):
+            with open('CONIN$', 'rb', buffering=0) as stdin:
+                write_input(stdin, source)
+
+                actual = b''
+                while not actual.endswith(b'\n'):
+                    b = stdin.read(read_count)
+                    actual += b
+
+                self.assertEqual(actual, expected, 'stdin.read({})'.format(read_count))
+
+    # bpo-38325
+    @unittest.skipIf(True, "Handling Non-BMP characters is broken")
+    def test_partial_surrogate_reads(self):
+        # Test that reading less than 1 full character works when stdin
+        # contains surrogate pairs that cannot be decoded to UTF-8 without
+        # reading an extra character.
+        source = '\U00101FFF\U00101001\r\n'.encode('utf-16-le')
+        expected = '\U00101FFF\U00101001\r\n'.encode('utf-8')
+        for read_count in range(1, 16):
+            with open('CONIN$', 'rb', buffering=0) as stdin:
+                write_input(stdin, source)
+
+                actual = b''
+                while not actual.endswith(b'\n'):
+                    b = stdin.read(read_count)
+                    actual += b
+
+                self.assertEqual(actual, expected, 'stdin.read({})'.format(read_count))
+
+    @requires_resource('console')
+    def test_ctrl_z(self):
+        with open('CONIN$', 'rb', buffering=0) as stdin:
+            source = '\xC4\x1A\r\n'.encode('utf-16-le')
+            expected = '\xC4'.encode('utf-8')
+            write_input(stdin, source)
+            a, b = stdin.read(1), stdin.readall()
+            self.assertEqual(expected[0:1], a)
+            self.assertEqual(expected[1:], b)
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/crates/vm/src/stdlib/io.rs b/crates/vm/src/stdlib/io.rs
index 3fc8b305a..768df4cb7 100644
--- a/crates/vm/src/stdlib/io.rs
+++ b/crates/vm/src/stdlib/io.rs
@@ -29,6 +29,8 @@ fn file_closed(file: &PyObject, vm: &VirtualMachine) -> PyResult<bool> {
     file.get_attr("closed", vm)?.try_to_bool(vm)
 }
 
+const DEFAULT_BUFFER_SIZE: usize = 128 * 1024;
+
 /// iobase_finalize in Modules/_io/iobase.c
 fn iobase_finalize(zelf: &PyObject, vm: &VirtualMachine) {
     // If `closed` doesn't exist or can't be evaluated as bool, then the
@@ -244,7 +246,7 @@ mod _io {
     }
 
     #[pyattr]
-    const DEFAULT_BUFFER_SIZE: usize = 8 * 1024;
+    const DEFAULT_BUFFER_SIZE: usize = super::DEFAULT_BUFFER_SIZE;
 
     pub(super) fn seekfrom(
         vm: &VirtualMachine,
@@ -5252,7 +5254,7 @@ mod fileio {
                 closefd: AtomicCell::new(true),
                 mode: AtomicCell::new(Mode::empty()),
                 seekable: AtomicCell::new(None),
-                blksize: AtomicCell::new(8 * 1024), // DEFAULT_BUFFER_SIZE
+                blksize: AtomicCell::new(super::DEFAULT_BUFFER_SIZE as _),
                 finalizing: AtomicCell::new(false),
             }
         }
@@ -5828,7 +5830,10 @@ mod winconsoleio {
         let Ok(name) = path_or_fd.str(vm) else {
             return '\0';
         };
-        let name_str = name.as_str();
+        let Some(name_str) = name.to_str() else {
+            // Surrogate strings can't be console device names
+            return '\0';
+        };
 
         if name_str.eq_ignore_ascii_case("CONIN$") {
             return 'r';
@@ -5928,7 +5933,7 @@ mod winconsoleio {
                 writable: AtomicCell::new(false),
                 closefd: AtomicCell::new(false),
                 finalizing: AtomicCell::new(false),
-                blksize: AtomicCell::new(8 * 1024),
+                blksize: AtomicCell::new(super::DEFAULT_BUFFER_SIZE as _),
                 buf: PyMutex::new([0u8; SMALLBUF]),
             }
         }
@@ -6131,7 +6136,7 @@ mod winconsoleio {
                 return Err(vm.new_value_error("Cannot open console output buffer for reading"));
             }
 
-            zelf.blksize.store(8 * 1024);
+            zelf.blksize.store(super::DEFAULT_BUFFER_SIZE as _);
             *zelf.buf.lock() = [0u8; SMALLBUF];
 
             zelf.as_object().set_attr("name", nameobj, vm)?;