A look at the Sinclair Microdrives which were originally an add-on for the ZX Spectrum. They were also built into the Sinclair QL and the ICL OPD as their standard data storage device. Later in this video is an interview with David Karlin, the QL designer. In the early 2000s David Karlin was the Managing Director of one of the UK's top FTSE-100 companies (SAGE). In this TV program software could be downloaded from a black and white spot on the TV screen to the Sinclair ZX Spectrum using a Light-Pen interface.