This is a modified version of MEGA65 Open ROMs (https://github.com/MEGA65/open-roms),
forked at upstream commit ad178dbe4d48cd6a317737a8e0e7e662f7e33d32.

Modified by Christian Werner, 2026-10-14, 2026-10-15, and 2026-10-17, for the mc64
computers of arnitech, a set of Minecraft mods (https://git.susdog.de/chris/arnitech). The
fork lives at https://git.susdog.de/chris/open-roms, branch mc64.

Changes:

- src/,,config_mc64.s: a new build configuration, copied from src/,,config_c64.s, with its
  own config ID ($6D), the brand "MC64", and BCD_SAFE_INTERRUPTS turned off.
- Makefile: targets for that configuration, build/kernal_mc64.rom and build/basic_mc64.rom,
  made the same way as the c64 ones.
- src/kernal/iec/ciout.s (2026-10-15): CIOUT buffers its byte in TBTCNT, where the send
  routine takes it from, not in BSOUR (upstream PR #113).
- src/kernal/iec/close_iec.s (2026-10-15): CLOSE sends LISTEN, $E0 plus the secondary
  address, and UNLISTEN; it sent a command ORed with zero page $E0 and no LISTEN.
- src/kernal/iec/chkin_iec.s, ckout_iec.s (2026-10-15): CHKIN and CHKOUT take the secondary
  address from SAT, not from LAT, the logical file numbers.
- src/kernal/iec/tksa.s (2026-10-15): TKSA sends the secondary address it is given, without
  ORing $90 into it (upstream issue #116).
- src/kernal/iec/iec_tx_byte.s (2026-10-15): a data byte that no listener holds DATA for
  sets ST to $80 (device not present) and returns, instead of waiting forever.
- src/kernal/iec/close_iec.s (2026-10-15): a CLOSE that finds no device sets ST to $80
  (device not present), and still frees the file number.
- src/kernal/iec/unlsn.s, untlk.s (2026-10-15): UNLSN and UNTLK end with CLK, DATA, and ATN
  released; UNLSN left CLK pulled, and UNTLK waited for a talker to pull CLK, which after
  UNTALK none does, and then left CLK pulled.
- src/kernal/iec/iec_return.s (2026-10-15): a serial routine that finds no device releases
  CLK, DATA, and ATN; it left CLK pulled.
- src/,,config_mc64.s, src/aliases/,aliases_hardware_arnitech.s, src/kernal/arnitech/
  (new), Makefile, src/kernal/init/fda3.ioinit.s, CONFIG.md (2026-10-17): a new option,
  ARNITECH_CONTROLLER, on in the mc64 configuration only. IOINIT sets CIA #1's TOD on 50 Hz
  and, if the Arnitech controller's signature is at $DE80, from the controller's clock. The
  Arnitech jump table at $FF00 wraps the controller's registers: "ARNI", a version, an entry
  count, and JMPs from $FF06 to find a Card by its type and to set the TOD.
- NOTICE: this file.

The licence terms are unchanged; see LICENSE, COPYING, and COPYING.LESSER.