turbotach

[turbobug73]

No interior topic, so here it goes:
I was wondering if porsche ever made a turbo model with a mechanical boost gauge integrated into the tach. The mid-eighties 944T had one, but it gets its signal from the computer, not just a direct vacuum/pressure line. It seems a bit expensive to me to have a 944 computer just to use that gauge. Also, if and early 911T did come so-equipt would the tach work with a 4 cylinder engine?
thanks