Does FS2002 differentiate between the two or do we basically get true airspeed? If I wanted to fake it...is there a good method?

Yes, it certainly does ...:-)You can set it under Options-Realisme...Rob

Okay, given that, how do I differentiate when I am setting a gauge? If I have TAS chosen in settings, can I fake IAS or vice versa?Thanks,

Setting which gauge ???As far as I know, everything in FS uses IAS and never TAS.Rob

I was going to do an indicated airspeed and true airspeed gauges. As altitude increases...IAS will be less than TAS. Correct? I suppose I could just take IAS and multiply by some facto give altitude? Is this reasonable?

Move to FS9 and you will able read IAS and TAS whatever you want :)

If you make a gauge (either .gau, or .xml) you can directly read the actual IAS, TAS, windirection and -speed, and Groundspeed from FS variables; so why do you need a conversion gauge ??If you have something else in mind:a rule-of-thumb for conversion TAS to IAS v.v. is:TAS = IAS + (2% IAS per 1000 ft altitude) knots.But that's not very accurate (influenced o.a. by air pressure).No difference between FS2002 and FS9 by the way in this respect.Rob