The Sinclair ZX Microdrive is a magnetic mass storage media, that uses small endless tape cartridges. It was initially released as an external drive for the ZX Spectrum in 1983. The Sinclair QL, released one year later, came with two internal Microdrives installed.
Already back then, Microdrives were regarded as somewhat unreliable, which makes working with them quite challenging today, decades later. In particular the tape cartridges are often no longer usable. This prompted the development of a Microdrive emulator. Different from existing “modern day” mass storage solutions for Spectrum & QL, the goal was to create a fully transparent and “historically correct” emulation of the Microdrive. Using this emulator should not feel different from using a real Microdrive. For that reason, it works on the level of the hardware Microdrive interface, and does not employ any system hooks on the Spectrum/QL.