Boot any Apple ][ disk on any Apple ][
▒▒▒ DOWNLOAD ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
(BIN) Anti-M (140KB disk image)
version 2.3, released 2024-12-08
▒▒▒ ABOUT ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
Many early Apple II games only worked on the original Apple II or
Apple ][+. They refuse to boot on later models, often displaying an
"M" error code. This was due to overly aggressive copy protection;
late in the boot process, there is code that checksums the ROM and
reboots if it's not recognized. The games themselves would work
fine if they were allowed to boot past this ROM check.
Other games fail on an enhanced Apple //e, due to subtle
differences between 6502 and 65c02 processors. Still others fail on
an Apple //c or IIgs, due to changes in the boot PROM code. ProDOS
fails to boot on clones like Franklin and Pravetz. Then there are
some very early games that require a 13-sector drive.
Anti-M uses a modified boot PROM that can boot any disk, then
controls the game's bootloader long enough to bypass the ROM check
and patch any 6502- specific opcodes. The result: you can boot any
Apple ][ disk on any Apple ][.
▒▒▒ USAGE ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
Boot the Anti-M disk. When it prompts you to insert your original
disk, do so, then press <RETURN>. The game should boot normally.
▒▒▒ SUPPORTED GAMES ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
i* ABM (MUSE)
i* Beer Run (Sirius)
i* Bug Attack (Cavalier)
i* Choplifter (Broderbund) [1]
i* Computer Air Combat (SSI)
i* Computer Foosball (Sirius)
i* David's Midnight Magic (Broderbund) [1]
i* Disk Recovery (Sensible Software)
i* Dogfight (Micro Lab)
i* Dueling Digits (Broderbund)
i* Eggs-It (Gebelli)
i* Frogger (On-Line Systems) [1]
i* Gamma Goblins (Sirius)
i* Genetic Drift (Broderbund)
i* Hard Hat Mack (Electronic Arts) [1]
i* High Orbit (Gebelli)
i* Horizon V (Gebelli)
i* Jawbreaker ][ (On-Line Systems)
i* Juggler (IDSI)
i* Labyrinth (Broderbund)
i* Lady Tut (Progame)
i* Lazer Silk (Gebelli)
i* Lunar Leepers (On-Line Systems)
i* Neptune (Gebelli)
i* Odin (Odesta)
i* Orbitron (Sirius)
i* Palace in Thunderland (Micro Lab)
i* Pest Patrol (On-Line Systems)
i* Phaser Fire (Gebelli)
i* Quadrant 6112 (Sensible Software)
i* Red Alert (Broderbund)
i* Russki Duck (Gebelli)
i* Seafox (Broderbund)
i* Sensible Speller (Sensible Software)
i* Serpentine (Broderbund) [1]
i* Sky Blazer (Broderbund)
i* Space Adventure (Sierra Software)
i* Space Eggs (Sirius)
i* Space Quarks (Broderbund)
i* Star Blazer (Broderbund)
i* Star Maze (Sir-Tech)
i* Star Thief (Cavalier)
i* Trick Shot (IDSI)
i* Typing Tutor (Microsoft)
i* Ultracheckers (Malibu Microcomputing)
i* Zenith (Gebelli)
i* all 13-sector disks (e.g. Epyx, Edu-Ware, many others)
i* all ProDOS disks
Footnote 1: this game was later re-released with different copy
protection. Only the first release requires Anti-M.
▒▒▒ FAQ ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
Does Anti-M patch my original disk?
No! All patches are done in memory only. If you reboot your
original disk (without running Anti-M), it will fail as usual,
because the ROM check or other incompatible code is still there.
Can I use Anti-M from a hard drive?
Yes! Copy the ANTI.M.SYSTEM file to anywhere on your ProDOS hard
drive and run it with your favorite launcher. Bonus feature: when
launching Anti-M from a hard drive, it will skip the prompt and
immediately boot slot 6, drive 1.
But wait, there's more!
Anti-M can also boot many games from drive 2, including all the
games listed above. If you launch Anti-M from slot 6 and it detects
a disk in drive 2, it will skip the prompt and immediately boot
from drive 2. Otherwise, you can press 2 at the prompt to boot from
drive 2 instead of drive 1.
To disable auto-boot and show the prompt, even if Anti-M would
normally skip it, you can press either joystick button (open-apple
or closed-apple key) while launching Anti-M.
▒▒▒ LICENSE ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
Anti-M is (c) 2019-2024 by 4am and is distributed under the MIT
license.
(HTM) Anti-M repository on GitHub