In April, I started reverse engineering the MSR605X magnetic stripe reader. Progress has basically paused at this point as I handle other affairs, but I figured that I may as well document what I have learned so far. My code for this little project is on Gitlab. This post won’t describe how magstripe readers work. If you’re interested, Major Malfunction gave an excellent in-depth talk on the subject. For this post, we only need to know that chip on the magstripe reader measures some stuff and sends us some bytes via USB.