Old IBM magnetic media Yes, two cartridges have a total capacity of 100mb, the same as the staging disks, IBM 3330-1. However, the entire cartridge contents are not staged, only the cylinders that have the requested data. Not sure why your cartridges were empty. Here?s a link to my ?working ? 3850 mass storage robotic arm for your viewing pleasure! *https://www.youtube.com/watch?v=V8ifNxDgxuY&pbjreload=10* <https://www.youtube.com/watch?v=V8ifNxDgxuY&pbjreload=10> ?\_(?)_/?