On 2003-11-15, J M Goodey wrote:
No its the mater Oscillator on an old Farfisa Electronic Organ
It is a dual multi vib.
Same as a SN74221 but with pins in a different order.
Google comes up with nothing helpful.

It should be possible to work it out.

SN74221 is 16 pins; is SN29730N also 16 pins?

You can come up with candidates for GND and Vcc by checking which pins are
hooked to the power plane.

Each of the two halves has a true and a complement output. With the circuit
operating you should be able to see these on a scope.

The data sheet shows an external resistor from Vcc to each Rext/Cext, and a
capacitor from each Rext/Cext to Cext.

The A inputs will be either wired to the controlling circuit or tied to
ground. The B inputs will either be wired to the controlling circuit or
tied to Vcc. Uh, unless half the chip is unused, in which case 2A will be
tied to Vcc and/or 2B will be tied to ground.

If the CLR inputs are unused they will be tied to Vcc.

If only a true or complement output is used, then the other one will be a
no-connect.

Let us know what you find out.

-- uns