TB-303 BPM tempo controll

[*Star Project]

Hi!

One of the modifications I have been wanting to do
on my 303 clone is to show the user the selected
BPM on a 3 part LED display. 
First i thought I could replace the Tempo pot with a
digital 256-260 step pot but found only 10K Ohm's ones.
So then i got curious on the tempo signal the CPU recieves
from the tempo circuit or the sync jack.
Is it possible to get a BPM value out of this signal?
In case it is, how? What values of this signal tells 
the tempo?
Please point me in the right direction.
Links to websites with info regarding this kind of stuff
is highly appriciated.
Thanks in advance...

// Andreas