microdrive

A miniature hard disk.

One-inch disks typically held about 8 to 10 GB and microdrives were either 2 or 4 GB.

An early computer storage system using cartridges of looped tape.

1984, Alison Maguire, interviewed in SINCLAIR talks... (in Crash magazine, issue 3, April 1984) http://www.crashonline.org.uk/03/sinclair.htm 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.

The Spectrum has its own inexpensive mass storage unit - the microdrive which starts at about £150 for 100k of storage, but this may not be suitable in all cases, since the storage unit may be damaged if turned on with the disc in position.

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.