wikipedia article http://en.wikipedia.org/wiki/HP_35s says "Equation solver (a feature first seen on the HP-34C)". While it is true that HP-34C was the first with RPN Solve, what was the first calculator with algebraic ALG EQN Solver?

Karl Schneider's article http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/articles.cgi?read=556 does not give the exact answer, what model was the first with EQN Solver? HP-17B?