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. I've gone to this much trouble with testing because (a) there used to be some real issues, and (b) because inevitably, someone is going to find a DOS or loader that can't load it. I'm going to point to this documentation, and tell them their DOS/loader is broken, not my game. 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 (works with MIO enabled too) - SIDE2: success (older Taipan build though, need to get results for latest) - APE loader: success - DOS XL 2.30: success - Micro SpartaDOS 2.2 and 4.6: success. - RealDOS build 0032: success (even with MIO active and TDLINE running!) - Atarimax flash cart EXE loader: success - SpartaDOS 3.2dx: success when loading from floppy, hard disk, or MIO RAMdisk. Fails when attempting to load from APE emulated drive under this DOS (which I suspect isn't Taipan's fault). 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. - BeweDOS 1.30: success. - 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 all of them. It at least works on 2.0S, 2.5, MyDOS, and SpartaDOS X.