On manual targetting how do I compute target speed?

[Castout]

I'm wondering that now I give the u-boat mission/SH4 1.5 a try well the damn button to calculate the target speed is still broken.

How do you play with manual solution?

I love SH3. I even play SH3 with modded TDC so I use mechanical computer dials to make my solution.

SH4 even if the measuring speed was not broken it would still feel arcadish. I gave up on SH4 after the first 2 patches or was that three? Now even with v1.5 it's still proving itself not a worthy successor to SH3.