C64net

Free plan Windows

What C64net is

C64net is a free Windows emulator for the Commodore 64, written in C#. It uses cycle-based timing to coordinate the emulated chips and models a 1541-II disk drive at hardware level. Its graphics support covers the VIC-II, including modes, sprites, and collision detection, with keyboard and joystick input also available. C64net loads D64 disk images and can save or restore emulator state, but saves are written only at the end of a frame. It does not emulate SID sound, REU expansion, or tapes, and D64 bad-sector extensions are unsupported. Only documented CPU opcodes are implemented; an undocumented opcode causes a crash. ROM files are not included and must be obtained separately and placed in the project ROM folder or beside the executable. The maker says this C# implementation was abandoned after a C++ reimplementation and presents it as a basis for explaining emulation. The repository identifies its license as GPL-3.0.

Who it suits

C64net may suit Windows users seeking a Commodore 64 emulator focused on cycle timing, VIC-II graphics, and 1541-II drive emulation. It is also presented as a base for explaining emulation.

What it does well

Free to use on Windows.
Models 1541-II drive hardware.
Includes VIC-II graphics and keyboard input.
Emulator state can be saved or loaded.

What to know first

SID sound, REU, and tape emulation are unavailable.
Only D64 disk images are supported.
ROM files must be obtained separately.
Undocumented CPU opcodes cause a crash.

Limits

C64net has no SID, REU, or tape emulation, and supports D64 disk images only. Undocumented CPU opcodes cause a crash, and saves are written only at the end of a frame.

Getting started

Open the C64net project repository
Obtain the required ROM files separately
Copy the ROM files into the project ROM folder or beside the executables
Run C64net on Windows
Load a D64 disk image

Verdict

C64net covers key Commodore 64 graphics, input, and disk-drive functions, but lacks sound, tape, and REU emulation. The maker says this C# version was abandoned after a C++ reimplementation.

Questions

What does C64net emulate?

It emulates the Commodore 64, including VIC-II graphics, keyboard and joystick input, and a 1541-II disk drive.

Which platform does it support?

C64net supports Windows.

Is C64net free and open source?

It is free, and the repository identifies its license as GPL-3.0.

Which disk-image format works?

D64 is the implemented disk-image format. D64 bad-sector extensions are unsupported.

Are ROM files included?

No. ROM files are excluded for legal reasons and must be obtained separately, then placed in the ROM folder or beside the executables.

Does it emulate sound and tapes?

SID sound-chip emulation, REU emulation, and tape emulation are unavailable.

Facts from C64net's own pages

Audio limit: SID chip emulation is not implemented. · github.com, 8 Oct 2026
Compatibility limits: Only documented CPU opcodes are implemented, and executing an undocumented opcode causes the emulator to crash. · github.com, 8 Oct 2026
Disk images: D64 is the only disk-image format implemented, and D64 extensions for bad-sector emulation are unsupported. · github.com, 8 Oct 2026
Drive emulation: It emulates a 1541-II disk drive at the hardware level, which uses more resources but improves compatibility. · github.com, 8 Oct 2026
Emulation timing: The emulator uses cycle-based emulation to synchronize chips and emulate their timing. · github.com, 8 Oct 2026
Graphics: It emulates the VIC-II graphics chip, including graphic modes, sprites, and collision detection. · github.com, 8 Oct 2026
Hardware coverage: The implementation covers much of the hardware needed to run games, including the VIC-II graphics chip and keyboard and joystick input. · github.com, 8 Oct 2026
Input: The implementation includes keyboard and joystick emulation. · github.com, 8 Oct 2026
License: The repository identifies its license as GPL-3.0. · github.com, 8 Oct 2026
Missing features: SID sound-chip emulation, REU emulation, and tape emulation are unavailable. · github.com, 8 Oct 2026
Other limits: REU and tape emulation are unavailable, and only documented CPU opcodes are implemented. · github.com, 8 Oct 2026
Product: C64net is a Commodore 64 emulator written in C#. · github.com, 8 Oct 2026
Project status: The maker says this C# implementation was abandoned after a C++ reimplementation and describes it as a base for explaining emulation. · github.com, 8 Oct 2026
Purpose: C64net is a Commodore 64 emulator written in C#. · github.com, 8 Oct 2026
ROM files: ROM files are excluded for legal reasons and must be obtained separately and placed in the project ROM folder or beside the executable. · github.com, 8 Oct 2026
ROM requirement: ROM files are excluded for legal reasons and must be obtained separately and copied into the project ROM folder or alongside the executables. · github.com, 8 Oct 2026
Save states: Emulator state can be saved or loaded, with saves written only at the end of a frame. · github.com, 8 Oct 2026
Timing: The emulator uses cycle-based timing to synchronize chips and implements real-drive emulation of a 1541-II disk drive. · github.com, 8 Oct 2026

Where C64net stands on Freedom251

Commodore 64 Emulators#13 of 31