From Michael Boddicker's private collection
The Oberheim OB-1 monophonic synthesizer was Oberheim's first completely programmable analog synthesizer, and possibly the first fully programmable monosynth from any brand. The OB-1 could store eight onboard patches with touch-sensitive buttons and interfaced with a cassette interface for external storage. Based on the SEM, the instrument added ADSR envelopes, a noise generator, and a switchable 2 pole / 4 pole VCF with keyboard tracking.
Later models of the OB-1 were graphically stylized after the OB-X, with large gray blocks surrounding each control section.