 In June 1955, Philco was awarded a contract with the National Security Agency to build a transistorized scientific computer, which was named the "SOLO" and used high-frequency surface-barrier transistors.The SOLO transistorized computer was the world's first completely transistorized computer, and was later commercially marketed by Philco as the Transac S-1000 scientific computer model.Also, later in 1955, Philco contracted with the United States Navy David Taylor Basin Research Unit to build a larger-scale fully transistorized computer using its high-frequency surface-barrier transistor technology, named the CPXQ model.