Snow emulates classic (Motorola 68k-based) Macintosh computers. It features a graphical user interface to operate and debug the emulated machine. The aim of this project is to emulate the Macintosh on a hardware-level as much as possible, as opposed to emulators that patch the ROM or intercept system calls.

For more information and downloads, go to the website. You can view a limited online demo here

It currently supports the following models:

• Macintosh 128K/512K/512Ke
• Macintosh Plus
• Macintosh SE (both non-FDHD and FDHD)
• Macintosh Classic
• Macintosh II (both non-FDHD and FDHD)
• Macintosh IIx, IIcx, SE/30

Currently supported hardware:

• Motorola 68000, 68020, 68030 CPUs
• Motorola 68881, 68882 FPUs
• Motorola 68851 PMMU
• IWM and SWIM floppy controllers
• GCR 400K/800K floppy disk drives (up to 3 on SE)
• GCR/MFM 1.44MB 'SuperDrive' floppy disk drive (currently read-only)
• SCSI hard disk drives (up to 7)
• SCSI CD-ROM drive
• Macintosh Real-Time Clock
• Macintosh keyboard/mouse
• ADB keyboard/mouse
• Audio output (PWM-based audio on compact Macs and ASC on newer models)
• Macintosh Display Card 8-24 with various monitor types (models with NuBus)

Supported floppy image formats:

• Apple DiskCopy 4.2 (sector-based)
• Apple Disk Archive / Retrieval Tool ('DART') (sector-based)
• Applesauce A2R 2.x and 3.x (flux)
• Applesauce MOOF (bitstream and flux)
• PCE Flux Image (PFI, flux)
• PCE Raw Image (PRI, bitstream)
• Raw images (sector-based)
• Any format (Mac 1.44MB or PC) supported by Fluxfox

Debugging features:

• Breakpoints (execution, bus access, system trap, exception, interrupt level)
• Watchpoints with editing
• Single step, step over, step out
• Disassembly view
• Register view with editing
• Memory viewer with editing
• Instruction history view with export functionality
• System trap history viewer
• Peripheral debug view
• Terminal for the serial ports

Networking and interfacing features:

• TCP and PTY bridges for serial ports
• LocalTalk over UDP
• Emulated Ethernet adapter with userland NAT

See the BUILDING.md file for instructions on building.

• Thanks to raddad772 for the excellent 68000 JSON test suite
• Thanks to Daniel Balsom for creating the Snow mascot art and for the Fluxfox library
• Thanks to Andrew Yaros for contributing the application icon
• Thanks to the people of the Emudev and Applesauce communities for their infinite wisdom
• The Musashi (by Karl Stenerud) and MAME ( many authors) projects have been used as a reference for poorly documented components
• The BlueSCSI Toolbox protocol and software is used in and distributed with Snow with permission of Eric Helgeson