PCSX2 modem fork brings online Armored Core multiplayer to PC

Armored Core’s PS2-era modem duels finally have a PC home. ddobokki released pcsx2_modem on April 13 as a GitHub project, and the fork adds built-in Omron ME56PS2 USB modem emulation to PCSX2 so two instances can meet online over TCP/IP instead of being stranded on original hardware.

The release page labels pcsx2_modem_v1.0.0 as “Latest” and describes it as “enjoy ac 2aa, 3, sl versus,” a clear sign that Armored Core 2 Another Age, Armored Core 3 and Armored Core: Silent Line are the first headline targets. Those are exactly the kinds of PS2 online modes preservation has struggled to keep alive, especially when the original networking depended on modem connectivity that most players no longer have access to.

The setup still asks for some tinkering, but it is the kind of tinkering emulation communities know well. The how-to guide says one player runs in server mode as the answering side while the other uses client mode as the calling side. It also says the player can enter any number in the dial string, and if a valid IP is entered, the connection goes directly. Even when the dial string is not an IP, the modem emulation can still connect using the configured remote host and port.

Under the hood, the fork documents the emulated device as an FTDI FT232-style USB modem with VID 0x0590 and PID 0x001A. That detail matters because it shows how far this goes beyond a menu tweak: pcsx2_modem translates old AT commands into TCP socket operations, letting the game believe it is talking to a real modem while the traffic actually rides a modern network.

The bigger story is preservation. PCSX2’s official site says the emulator supports more than 2,600 PS2 games, and its stable releases are infrequent compared with nightly builds, which helps explain why a special-purpose fork can catch fire so quickly when it unlocks a lost feature. For players trying to preserve Japanese-exclusive or hard-to-access online modes, this is not just a novelty fork. It is a way to restore a slice of multiplayer history that had been effectively locked to original hardware until now.

Early reaction has already spilled into public view, with demo footage appearing on YouTube under titles like “AC2AA Modem VS. over the pcsx2_modem fork,” and matches being shared on X. The scene that used to live behind a telephone-style barrier is suddenly portable, recordable and playable on modern PCs.