/vizdiff

Compare two identically sized files for byte by byte differences, e.g. floppy disk extracts

Primary LanguagePythonGNU General Public License v3.0GPL-3.0

vizdiff (Visual Binary Diff)

Compare two identically sized files for byte by byte differences, e.g. floppy disk extracts

Intro

Output a PNG visualization of two byte-streams.

A rudimentary tool to begin with to compare two identically sized streams. Lots of scope for improvement if it proves to be useful.

Examples

Example of a diff between two 5.25" disk images (same disk), ~10 years apart

KEY: Purple is where the disk images are identical, yellow is where there is a difference.

image

Hypothesis based on early testing

image

Testing volility today?

  1. We will first notice a checksum difference,
  2. But how different are they?

If there are no legacy disk images/checksums to compare against, then we can still understand the volility of the disk today. Take two extracts, with a small amount of time between doing so and then compare them.

I believe this is the equivalent to be hard of seeing/hearing.

The reader will do its best to understand, but the signal is analogue so its understanding is on a spectrum. We're not expecting binary results from a volatile analog medium.

What an archive may need

Is an ability to make a statement about the health of the disk. To make a disclaimer about data and record integrity. The user of the archive has to be able to fill in the gaps without more questions being raised - provenance.

License

GPL Version 3: https://github.com/exponential-decay/visual-binary-diff/blob/master/LICENSE