Micro/CPU 100

About the Micro/CPU 100

The Sherwood Micro/CPU 100, introduced in 1977 and designed by Larry Schotz, is a pioneering FM stereo tuner known as the world's first computer-controlled tuner. It features digital phase-locked-loop tuning with a digital numeric frequency display and an analog-style tuning knob with a flywheel mass for smooth operation. The tuner includes sophisticated circuitry with a microprocessor managing computer-like functions such as station presets and alphanumeric call letter displays. It has six varactor diodes for tuning, dual-gate MOSFETs in the RF front end, and a JFET mixer. The unit offers selectable IF bandwidths for high selectivity or low distortion, an auto-stereo noise filter, mono/stereo mode, and selectable de-emphasis for Dolby FM compatibility. It stores up to 48 favorite stations with non-volatile memory backed by a replaceable battery. The tuner weighs about 15.4 kg and measures 508 x 162 x 379 mm. It was originally7 µV), low distortion (0.15%), high signal-to-noise ratio (72 dB), and advanced digital control features. Later versions were sold under the Draco brand after a dispute, with some improvements and fewer issues. The Micro/CPU 100 remains a rare and collectible piece of vintage audio equipment.