I have just bought a semi automatic, but I am used to an automatic, when you take off the handbrake when parked on a hill should you be on the gas? I'm finding the transition tricky as I either roll back or shoot forward. Any tips please?
you don't say what type of semi-automatic. Speedgear, Selespeed, other
Semi-automatics (well most/all of Fiat ones) use either a standard dry clutch plate or I think a steel drive band that is hydraulically operated by a high pressure pump. When the engine is at idle the clutch/band is disengaged. On the level then the car will sit there. On a hill it will roll forwards/backwards.
When revs are lifted the clutch is gradually released and the car moves. On the level then only a small increase in revs is required. On an incline then more revs are required.
Have a practice on a level surface with no handbrake. Do a few gentle starts to get a feel of the "bite" point. Do the same with the handbrake ON and releasing the handbrake as though you were driving a manual gearbox/clutch setup. Now find a small incline and start again.
You say shoot forward and this can happen because the revs are too high at the time you release the handbrake.
There is of course the possibility that the system needs recalibrating or there is a fault.