Correspondence, in 1970, between Harry Garland and Oliver P. Ferrell, Editor of Popular Electronics, regarding the article "A Triggered Sweep for your Scope". The article described an original design by Harry Garland and Roger Melen, two Stanford University students, that was published as "Add Triggered Sweep to your Scope" in the July 1971 issue of Popular Electronics. This was the first collaboration of Garland and Melen, who later went on to found Cromemco.