Changing frequency of output tach signal

[saturnslut]

Hi
Has anyone developed a circuit to multiply the output frequency of the tach driver from a MS2? The Saturn tachometer uses a x3 input frequency of a normal tach.
Ex: The megasquirt outputs a 33.3 hz signal at 1000rpm, The Saturn tachometer wants 100hz signal to display 1000 rpm. The 0-5v square wave is enough to drive the tach.

[billr]

It can be done with a phase-locked-loop (PLL) like a CMOS 4046 and a divide-by-three counter. Maybe somebody knows of a more "off the shelf" solution, I have seen one on my son's bike...