AppleWin

Apple II emulator for Windows

AppleWin is a fully-featured emulator supporting different Apple II models and clones. A variety of peripheral cards and video display modes are supported (eg. NTSC, RGB); and there's an extensive built-in symbolic debugger.

Apple II models supported include:

• II (original)
• II Plus
• //e (original)
• //e (enhanced)
• Various clones (Pravets, TK3000, Base 64)

There is currently no support for the //c, //c+, Laser 128, Laser 128EX, Laser 128EX2, or Apple IIgs.

Peripheral cards and add-on hardware supported:

• Mockingboard, Phasor and SAM sound cards
• Disk II interface for floppy disk drives
• Hard disk controller
• Super Serial Card (SSC)
• Parallel printer card
• Mouse interface
• Apple IIe Extended 80-Column Text Card and RamWorks III (16MB)
• RGB cards: Apple's Extended 80-Column Text/AppleColor Adaptor Card and 'Le Chat Mauve' Féline.
• CP/M SoftCard
• Uthernet I and II (ethernet cards)
• Language Card and Saturn 64/128K for Apple II/II Plus (and Saturn 128K for any Apple II in any slot)
• 4Play and SNES MAX joystick cards
• VidHD card (functionality limited to IIgs' Super Hi-Res video modes)
• Commander X16 VERA card (slot 2 or 4): 640×480 VGA/NTSC graphics, 2 layers, 128 sprites, 256-colour palette, 16-channel PSG + PCM audio, optional YM2151 FM daughterboard (A2VERA board), SD card (SPI), IRQ
• No Slot Clock (NSC)
• Game I/O Connector copy protection dongles

Commander X16 VERA card

Development Note: The VERA and FM expansion card features in this fork were architected, designed, and verified by human contributors, with implementation assistance from AI coding tools in compliance with AppleWin's AI Tool Use Policy.

The VERA expansion card (port of apple2ts's TypeScript VERA) is installed in slot 2 or 4 (-s2 vera / -s4 vera). It provides a 640×480 VGA/NTSC graphics core (2 layers, 128 sprites, 256-colour palette), a 16-channel PSG + PCM audio core, an SD card (SPI) storage interface, and an IRQ line.

FM daughterboard (YM2151) — the A2VERA board (prototype hardware "EV1" release) adds a Yamaha YM2151 FM chip addressed through the VERA Cx region. The socket can take a genuine YM2151 or the OPM2151 (a modern FPGA drop-in replacement for the vintage YM2151) — the emulated chip is the YM2151 either way:

• $Cs20 = YM_REG (register select), $Cs21 = YM_DATA (data write / status read) — mirroring the X16's $9F40 / $9F41.
• The chip is wrapped in source/VERACard/VERAYM.h/.cpp around the ymfm::ym2151 core (source/ymfm/, BSD-3-Clause). Native ~55,930 Hz output is linearly resampled to 44.1 kHz and mixed into the VERA DS voice buffer.
• Mixer balance — the X16 Developer Board mix is reproduced as (PSG + PCM) * 2 + YM (a full-volume PSG voice is only 1/8 of full scale). This is what keeps the PSG audible under the YM2151.
• ZSM retrigger — a key-off write to $08 clocks one native YM sample before an immediately following key-on, so every note re-attacks instead of only the first one.
• Can be enabled/disabled per slot (FM Card Enabled in the VERA configuration dialog, persisted per-slot in the registry). When disabled, $Cs20/$Cs21 fall through to the regular VERA register handling.
• Verified end-to-end (2026-10-16): a guest program writing the standard init + key-on sequence through $Cs20/$Cs21 produces a full-scale FM tone in the emulator's audio output. The veramusic Apple //e ZSM stream player (TITLE.ZSM, BOTHPSG.ZSM) also plays through this chain with PSG + FM. For automated verification, -fm-wav-dump captures the first 20 s of the mixed VERA buffer (stereo 16-bit @ 44100) to VERA-fm.wav next to the exe — opt-in; without the flag nothing is written.

Behaviour:

• Dual screen — when the VERA video output is disabled the Apple II (NTSC) image is shown; the VERA framebuffer is only painted when the software enables VERA video output (IsVideoOutputEnabled). This lets VERA software switch between the Apple II screen and the VERA 640×480 display.
• Audio — the VERA audio is self-contained (it does not borrow the Mockingboard/SSI263 audio model). UpdateSound() is driven directly by the DS play cursor so the write rate exactly tracks real-time playback — no drift, no periodic glitch. The DS ring buffer is ~3 frames (~50 ms) with a 1/2-buffer lead. PSG/PCM and FM are mixed with the X16 board balance, (PSG + PCM) * 2 + YM.
• SD Card (SPI) — emulates the SD/MMC SPI interface on $Cs1E (SD_DATA) and $Cs1F (SD_STATUS), supporting raw 512-byte block images (e.g. FAT32). Images can be mounted/unmounted via the Configuration -> Slots -> VERA -> Configure... dialog and persist in the per-slot registry configuration.
• Diagnostics — on a stall (emulator hang) the DS buffer is flushed so no lingering audio survives. Heartbeat + unhandled-exception info is written to VERA.log next to the exe (independent of the -log AppleWin.log).

Running

Download latest (stable) release: AppleWin v1.32.1.0

Release Notes: v1.32.1.0 | VERA Release: v1.32.1.0-vera

Building

To compile for Windows from source see:

• docs/compiling.txt

Unofficial Ports

These ports will allow you to build and run AppleWin on other platforms:

• Linux
• macOS

Contributing

Please see the CONTRIBUTING document before raising new bugs, features and especially PRs (Pull Requests). Note that upstream has established an AI Tool Use Policy (requiring human-in-the-loop, explicit marking of AI-generated contributions, and licensing compliance).

Next Version

Experimental build: pending

Please report new issues

Previous Versions

Last version supporting Windows XP: AppleWin v1.30.21.0

Last version supporting Windows 2000: AppleWin v1.29.16.0

Last version supporting Windows 98/ME: AppleWin v1.25.0.4