DF: a device associated with the instrument which is intended to perform a specific function, e.g. a repeat indication device, ticket printer, card reader, data input terminal, etc.
DF: a device associated with the instrument which is intended to perform a specific function, e.g. a repeat indication device, ticket printer, card reader, data input terminal, etc.
DF: a device associated with the instrument which is intended to perform a specific function, e.g. a repeat indication device, ticket printer, card reader, data input terminal, etc.