I have an old computer, probably manufactured in the 1990s, with e-mails from the late Dr Michael Lennon of Auckland University (passed away in 1999) on its hard drive. I think that these e-mails might be of significant historical interest to mathematicians (and probably others) because of the significant contribution that I believe Dr Michael Lennon made (in the 1970s I believe) to the knot theory breakthrough in the 1980s that resulted in the New Zealand mathematician Sir Vaughan Jones (who passed away in 2020 I believe) being awarded a Fields Medal in 1990. Because of the age of this computer and its hard drive, and the possible historical value of these old e-mails from Dr Michael Lennon, I wish to try to extract these e-mails from this old computer in such a way as to minimise the probability of triggering any hardware or software failure that could endanger this old data. I propose a method involving DTMF tones and also an alternative method involving a data logger attached to the serial port of this old computer. I would appreciate feedback on these proposed methods from people knowledable in this area (extraction of valuable data from possibly unreliable old computers) before attempting to go any further with the extraction process.