control an inkjet cartige

Hello,
Might someone happen to know a way to control the inkjet cartige with
pulse signals instead of the computer?
  would like to build a circuit for that purpose.
I want to be able to "shoot" ink droplets from all the nozzles at the
same time. I need to know how to operate each of the pizo crystals, and
then to operate them all.
I guess I can measure the electrical signal coming from the contacts
that match up with the ones on the cartridge, but always much easier,
if someone already has that information...
Thanks,
Hanan.