Default the --end option of bin2tap.py to 49152 for 128K TAP files

skoolkit/bin2tap.py

@@ -223,28 +223,32 @@ def main(args):
     loader_addr = namespace.loader
     if loader_addr is None and clear is not None:
         loader_addr = clear + 1
+    has_128k_options = out7ffd is not None and clear is not None and namespace.begin is not None
     if snapshot_reader.can_read(infile):
         org = 0
         begin = namespace.begin or 16384
-        end = namespace.end or 65536
-        ram = snapshot_reader.get_snapshot(infile)[begin:end]
-        if out7ffd is not None and clear is not None:
+        if has_128k_options:
             snapshot = snapshot_reader.get_snapshot(infile, -1)
             if len(snapshot) == 0x20000:
                 banks = {b: snapshot[b * 0x4000:(b + 1) * 0x4000] for b in (0, 1, 3, 4, 6, 7)}
+                end = namespace.end or 49152
+        else:
+            end = namespace.end or 65536
+        ram = snapshot_reader.get_snapshot(infile)[begin:end]
     else:
         snapshot = read_bin_file(infile, 0x20000)
-        if len(snapshot) == 0x20000 and out7ffd is not None and clear is not None:
+        if len(snapshot) == 0x20000 and has_128k_options:
             banks = {b: snapshot[b * 0x4000:(b + 1) * 0x4000] for b in range(8)}
             ram = list(banks.pop(5) + banks.pop(2)) + [0] * 16384
             org = 16384
+            end = namespace.end or 49152
         elif snapshot:
             ram = snapshot[:49152]
             org = namespace.org or 65536 - len(ram)
+            end = namespace.end or org + len(ram)
         else:
             raise SkoolKitError(f'{infile} is empty')
         begin = namespace.begin or org
-        end = namespace.end or org + len(ram)
         ram = ram[begin - org:end - org]
     if not ram:
         raise SkoolKitError('Input is empty (ORG={}, BEGIN={}, END={})'.format(org, begin, end))

sphinx/source/commands.rst

@@ -141,20 +141,20 @@ leaves the stack pointer alone, enabling the program to return to BASIC without
 crashing. The lowest usable address with the ``--clear`` option on a bare 48K
 Spectrum is 23952 (0x5D90).
 
-To create a TAP file that loads a 128K game, use the ``--7ffd``, ``--begin``,
-``--end`` and ``--clear`` options along with a 128K snapshot or a 128K binary
-file as input, where:
+To create a TAP file that loads a 128K game, use the ``--7ffd``, ``--begin``
+and ``--clear`` options along with a 128K snapshot or a 128K binary file as
+input, where:
 
 * ``--7ffd`` specifies the value to write to port 0x7FFD after all the RAM
   banks have loaded and before starting the game
-* ``--begin`` and ``--end`` specify the start and end addresses of the
-  code/data below 49152 (0xC000) to include on the tape
-* ``--clear`` specifies the address of the CLEAR command in the BASIC loader;
-  by default, the 128K RAM bank loader is placed one above this address
-
-Use the ``--loader`` option to place the 128K RAM bank loader at an alternative
-address. The lowest usable address with the ``--clear`` option on a bare 128K
-Spectrum is 23977 (0x5DA9).
+* ``--begin`` specifies the start address of the code/data below 49152 (0xC000)
+  to include on the tape
+* ``--clear`` specifies the address of the CLEAR command in the BASIC loader
+
+By default, the 128K RAM bank loader (which is 45 bytes long) is placed one
+above the CLEAR address. Use the ``--loader`` option to place it at an
+alternative address. The lowest usable address with the ``--clear`` option on a
+bare 128K Spectrum is 23977 (0x5DA9).
 
 +---------+-------------------------------------------------------------------+
 | Version | Changes                                                           |

sphinx/source/man/bin2tap.py.rst

@@ -79,20 +79,20 @@ Spectrum is 23952 (0x5D90).
 
 128K TAPES
 ==========
-To create a TAP file that loads a 128K game, use the ``--7ffd``, ``--begin``,
-``--end`` and ``--clear`` options along with a 128K snapshot or a 128K binary
-file as input, where:
+To create a TAP file that loads a 128K game, use the ``--7ffd``, ``--begin``
+and ``--clear`` options along with a 128K snapshot or a 128K binary file as
+input, where:
 
 * ``--7ffd`` specifies the value to write to port 0x7FFD after all the RAM
   banks have loaded and before starting the game
-* ``--begin`` and ``--end`` specify the start and end addresses of the
-  code/data below 49152 (0xC000) to include on the tape
-* ``--clear`` specifies the address of the CLEAR command in the BASIC loader;
-  by default, the 128K RAM bank loader is placed one above this address
-
-Use the ``--loader`` option to place the 128K RAM bank loader at an alternative
-address. The lowest usable address with the ``--clear`` option on a bare 128K
-Spectrum is 23977 (0x5DA9).
+* ``--begin`` specifies the start address of the code/data below 49152 (0xC000)
+  to include on the tape
+* ``--clear`` specifies the address of the CLEAR command in the BASIC loader
+
+By default, the 128K RAM bank loader (which is 45 bytes long) is placed one
+above the CLEAR address. Use the ``--loader`` option to place it at an
+alternative address. The lowest usable address with the ``--clear`` option on a
+bare 128K Spectrum is 23977 (0x5DA9).
 
 EXAMPLES
 ========

tests/test_bin2tap.py

@@ -586,6 +586,54 @@ def test_option_7ffd_with_128k_binary_file(self):
         tap_data = self._run(f'-b {begin} -e {end} -c {clear} --7ffd {out7ffd} {binfile}')
         self._check_tap_with_ram_banks(tap_data, data, banks, out7ffd, binfile, clear, begin)
 
+    def test_option_7ffd_with_snapshot_and_no_end_option(self):
+        data = [200, 201, 202]
+        begin = 49152 - len(data)
+        clear = 32767
+        out7ffd = 1
+        ram = [0] * 49152
+        ram[begin - 16384:begin - 16384 + len(data)] = data
+        sna_data = [0] * 27 + ram
+        sna_data.extend((
+            0, 0,    # PC
+            out7ffd, # Port 0x7ffd
+            0        # TR-DOS ROM
+        ))
+        banks = []
+        for bank in (0, 1, 3, 4, 6, 7):
+            if bank == out7ffd % 8:
+                banks.append((bank, ram[32768:]))
+            else:
+                banks.append((bank, [bank] * 16384))
+                sna_data.extend(banks[-1][1])
+        sna = self.write_bin_file(sna_data, suffix='.sna')
+        tap_data = self._run(f'-b {begin} -c {clear} --7ffd {out7ffd} {sna}')
+        self._check_tap_with_ram_banks(tap_data, data, banks, out7ffd, sna, clear, begin)
+
+    def test_option_7ffd_with_128k_binary_file_and_no_end_option(self):
+        data = [128, 129, 130]
+        begin = 49152 - len(data)
+        clear = 32767
+        out7ffd = 7
+        ram = [0] * 49152
+        ram[begin - 16384:begin - 16384 + len(data)] = data
+        bin_data = []
+        banks = []
+        for bank in range(8):
+            if bank == 2:
+                bin_data += ram[16384:32768]
+            elif bank == 5:
+                bin_data += ram[:16384]
+            elif bank == out7ffd % 8:
+                banks.append((bank, ram[32768:]))
+                bin_data += banks[-1][1]
+            else:
+                banks.append((bank, [bank] * 16384))
+                bin_data += banks[-1][1]
+        binfile = self.write_bin_file(bin_data, suffix='.bin')
+        tap_data = self._run(f'-b {begin} -c {clear} --7ffd {out7ffd} {binfile}')
+        self._check_tap_with_ram_banks(tap_data, data, banks, out7ffd, binfile, clear, begin)
+
     def test_option_b(self):
         bin_data = range(30)
         binfile = self.write_bin_file(bin_data, suffix='.bin')