microdrive

noun3

1. •
   A miniature hard disk.

   • One-inch disks typically held about 8 to 10 GB and microdrives were either 2 or 4 GB. — 2011
2. •
   (historical) An early computer storage system using cartridges of looped tape.

   • There are lots of things that will benefit from being on a microdrive cartridge but if you release something on microdrive you're only going to sell it to people with microdrive. — 1984
3. •
   A device for inserting microelectrodes into the brain.

   • The microdrive was invented so that electrodes could be lowered into the brain in order to isolate new neurons. — 2014