Here it is:

f = 1.44/[C*(Ra+2Rb)]

where Ra is between Vcc (Pin #8) and Pin #7 (Discharge)
      Rb is between Pin #7 (Discharge) and Pin #6 (Threshold)
      C is between Pin #6 (Threshold) and Ground (Pin #1)

ensure Pin #4 (Reset) and #8 (Vcc) are tied together, and Pin 5 (Control)
needs a filter cap if the circuit has noise problems.

ALWAYS  A L W A Y S  ALWAYS! Start with the cap. Set it by pulse width. Use
this table:

Cap(uFd)    Pulse width(Seconds)
--------------------------------
10.0             90m -  1.2
 1.0              9m - 120m
 0.1            900u -  12m
 0.01            90u - 1.2m
 0.001            9u - 120u
--------------------------------

Select your cap, THEN select the resistors. If you want to make it easy,
ASSuME the resistors are the same value, then you can use:

f = 0.48/R*C <==> R=0.48/f*C

If your resistor is abnormal in size, you have either chosen the wrong cap,
or you are doing some kind of real odd freq.

Have fun!

TAS
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