California Digital Library

Specimens of early computer systems stop working every day. One storage medium that was popular for home computers in the 1980s was the audio tape. The first home computer systems allowed the use of standard cassette players to record and replay data. Audio tapes are more durable than old home computers when properly stored. Devices playing this medium (i.e. tape recorders) can be found in working condition or can be repaired as they are made out of standard components. By re-engineering the format of the waveform the data on such media can then be extracted from a digitized audio stream. This work presents a case study of extracting data created on an early home computer system, the Philips G7400. Results show that with some error correction methods parts of the tapes are still readable, even without the original system. It also becomes clear, that it is easier to build solutions now when the original systems are still available.