Apple II gaming enthusiasts, brace yourselves for a game-changing release! Anti-M, the ultimate solution for running early Apple II games on any Apple II model, version 2.0 was just released. Developed to provide compatibility across the entire Apple II range, Anti-M allows you to enjoy classic games that were once restricted by overly aggressive copy protection and hardware limitations.
Breaking Down Anti-M: What Does It Do?
In the early days of Apple II gaming, some titles were notorious for refusing to run on newer Apple II models, displaying an ominous “M” error code. These compatibility issues were often attributed to aggressive copy protection mechanisms. As part of their boot process, these games would check the Apple II’s ROM, and if it didn’t match expectations, they’d promptly reboot, preventing gameplay.
Moreover, some games struggled with subtle differences between the 6502 and 65c02 processors, leading to issues on enhanced Apple //e models. Others failed to run on Apple //c or IIgs systems due to changes in the boot PROM code. Even ProDOS had its share of woes, refusing to boot on certain Apple II clones like Franklin and Pravetz. Additionally, a handful of early games relied on the elusive 13-sector drives, adding another layer of complexity.
Anti-M to the Rescue
Anti-M tackles these compatibility challenges head-on. It employs a modified boot PROM that can boot any disk, bypassing the ROM check and patching any 6502-specific opcodes within the game’s bootloader. The result? You can now boot any Apple II disk on any Apple II model without the dreaded “M” error code standing in your way.
How to Use Anti-M
Using Anti-M is straightforward:
- Boot the Anti-M disk.
- When prompted to insert your original game disk, do so.
- Press the <RETURN> key.
The game should now boot as if the compatibility issues never existed.
Supported Games
Anti-M boasts an impressive list of supported games that includes classics like Beer Run, Choplifter, Frogger, and many more. It even covers all 13-sector disks and ProDOS disks, ensuring a vast library of compatible titles. Note that later re-releases of some games with different copy protection may not require Anti-M.
Preserving Your Original Disks
One crucial aspect to highlight is that Anti-M does not modify your original game disks. All patches and modifications are performed in memory only. So, if you boot your original disk without running Anti-M, it will behave as it did before, complete with the ROM check and incompatible code.
Anti-M on Your Hard Drive
For added convenience, Anti-M can be run from a ProDOS hard drive. Simply copy the ANTI.M.SYSTEM file to your hard drive directory and launch it using your preferred launcher. A bonus feature is that when launched from a hard drive, Anti-M will skip the prompt and immediately boot from slot 6, drive 1.
Discover More with Anti-M
But wait, there’s more! Anti-M also offers the ability to boot games from drive 2. This includes 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. For those who prefer manual control, you can press 2 at the prompt to boot from drive 2 instead of drive 1.
And for those who wish to disable auto-boot and see the prompt, even when Anti-M would typically skip it, simply press either joystick button (open-apple or closed-apple key) while launching Anti-M.
With Anti-M, the era of Apple II gaming has been reinvigorated, breaking down barriers and allowing gamers to experience classic titles as they were meant to be. Say goodbye to compatibility woes and dive into a world of nostalgic gaming. Download the latest Anti-M disk image here, and relive the magic of Apple II gaming on any Apple II model you choose.
You can also download all of the source code from the Anti-M Github page at:
https://github.com/a2-4am/anti-m
