anyone know the ecu switching voltage for the ignitor?

i want to test one out of the car. i've read this:
http://www.gcw.org.uk/rover/ign.zip from graham woods excellent rover
200 web page. the only info it doesn't give is what signal voltage the
ecu gives the ignitor - and that would allow me to rig up a dry test.
i'm guessing it's 5v as the ecu is old skool electronics, but anyone
know for sure?

any help much appreciated!