MASTERFILE is a filing and retrieval system for use with the 48K ZX Spectrum. It is almost entirely machine-coded for compactness and speed, and offers about 32K of data per file. Files can be saved and loaded independently from the program, and stored either on cassette or Microdrive cartridge. Because MASTERFILE display formats are user-defined, the range of applications is enormous, both for domestic use and for business. Address lists, library catalogues, personnel files, stock inventories, school exam results, family trees - all these are easily handled by MASTERFILE.