The Autonetics RECOMP II was introduced by the Autonetics division of North American Aviation in 1958.
It had a 40 bit word size, 20 bit instruction size. Memory and registers were on a fixed head disk with 4080 words on standard tracks, 16 words on fast loop tracks, registers A, B, R, X each on their own high speed loop track, and one prerecorded read only clock track.
It had a complete set of built-in floating point operations, including square root. Floating point values used two words, one for the exponent and one for the fraction for a total of 80 bits.
The machine operated bit serial.