64S File
What are 64S files and how to open them
Are you having problems opening a 64S file or are you simply curious about its contents? We're here to explain the properties of these files and provide you with software that can open or handle your 64S files.
What is a 64S file?
A .64S file is a Hoxs64 State Snapshot file.
Hoxs64 state snapshot (.64s) files store a full running state of the Commodore 64 emulation as produced by the Hoxs64 emulator by David Horrocks. They are used to pause and later resume a game or program exactly where it was left off, restoring all hardware registers, memory, graphics chip state, sound chip state, and other emulator internals. Users see them when they choose "Save State" from Hoxs64's menu; later the same emulator reads them using "Load State." These snapshots work only with the same Hoxs64 version and configuration under which they were created.
Hoxs64 itself writes .64s files. Nothing external will meaningfully update them - resuming an emulated session only works if the emulator is loaded with the matching .64s file. The content captures both the volatile state (CPU registers, VIC, CIA, SID chip status, RAM contents, disk/tape state) and non‐volatile settings needed to resume the session.
Files begin with the ASCII signature COMMODORE64STATESNAPSHOT at byte offset 0, followed by the string Hoxs64 at offset 36.
How to open 64S files
Important: Different programs may use files with the 64S file extension for different purposes, so unless you are sure which format your 64S file is, you may need to try a few different programs.
We have not yet verified any programs for Windows that work with this specific file format. If you know one, please use the 'Suggest a program' link below. Thanks!
Last updated: August 16, 2026
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