The intended target for the .xex version of Taipan is really a 48K 800
with an 810 drive and DOS 2.0S. However, most people use something else
these days.

There are only two XL/XE specific things in Taipan:

- The checkmem code attempts to disable built-in BASIC if
  it's enabled, which won't work on an 800 (you get a "remove cartridge"
  message instead). Most .xex file games won't work with a BASIC cart in,
  so I don't consider this a problem (and at least Taipan fails gracefully
  instead of splattering the screen with ANTIC gibberish).

- Keyclicks are disabled on XL/XE, with POKE 731,1 (because the Apple II
  version has no keyclick). This doesn't work on an 800, but doesn't
  hurt anything either: You just get the game with keyclicks enabled,
  which at least one of my testers prefers anyway.

Unfortunately, the wide variety of Atari DOSes, both ancient and modern,
plus the various new bits of hardware (MyIDE, Atarimax Flash cart, etc)
leads to a compatibility nightmare. The rest of this file is a list of
DOSes (and other loaders), and their compatibility with Taipan.

At this point, all the "obvious" reasons for load failure have been
addressed. Loaders that fail now probably do so for hard-to-diagnose
reasons, or else because MEMLO is too high. Taipan loads at $2000,
which should *not* be a problem for any useful Atari DOS.

Tested on actual hardware:

- Atari DOS 2.0S: success
- Atari DOS 2.5: success
- MyDOS 4.55 (floppy): success
- MyDOS 4.55 (with MyIDE): success
- SpartaDOS X: success, with "X" command
- SIDE2: success (older build though, need to get results for latest)
- APE loader: success (older build, need newer results)
- DOS XL 2.30: success
- SpartaDOS 3.2dx: fails to load. This is 3.2d patched for the XF551 drive.
- SpartaDOS 3.2g/3.2gx with MIO: failure.

Tested on emulators:

- atari800 3.1.0 direct xex loader: success
- atari++ direct xex loader: success
- altirra direct xex loader: success
- SpartaDOS 3.2g and 3.2d on atari800: success (unexpectedly so)
- MyDOS 4.50 (floppy) on atari800: success
- SpartaDOS 1.1 on atari800: success (with STANDARD.SYS kernel).
                             I doubt that exiting the game will
                             work, as MEMLO is $2300 on this DOS.
- MyPicoDOS 4.03 on atari800: success
- Fenders 3-sector loader on atari800: success
- Atari DOS 3.0 on atari800: success
- Top DOS 1.5 on atari800: success
- "DOS 2.6f" on atari800: success
- Smart DOS 6.1d on atari800: success
- Super DOS 2.9 on atari800: failure. MEMLO is $35c1 on this DOS,
                             *way* too high!

Note: all the oddball DOSes at the end of the list are ones I really
used to run at various different times, in the old days. All the tests
with atari800, other than the direct xex loading, were done with SIO
patching disabled. On some of the DOSes, exiting the program may not work
(answering N to the "play again?" prompt); I didn't test this with most
of them.

Untested (waiting on results from testers):

- Atarimax flash cart EXE loader. An older Taipan build failed due
  to the loader leaving RAMTOP set to $a0. My first attempt to fix this
  worked, but broke loading with MyIDE and SDX. The current code *should*
  be fine, but I have yet to hear back from my tester about it.

Untested, but worth looking at:

- RealDOS, BeweDOS? probably same results as Sparta 3...