Yep, Casio had it back in 1984 on the CT-6000...it was called "Super Accompaniment.
A buddy of mine used to sell them from his home...I eventually bought my CZ synths from him.
The CT-6000 also had velocity AND aftertouch.
No PCM drums unfortunately, but the style patterns were very useful and pretty good for the time, and it was a well made instrument.
I remember my favorite sound was one called "Chorus"...ethereal, eerie and pure.
Ian
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Yamaha Tyros4, Yamaha MS-60S Powered Monitors(2), Yamaha CS-01, Yamaha TQ-5, Yamaha PSR-S775.