It would work in the case as long as the 3.3V processsor that connects to the MAX232 @5V supply has 5v tolerant I/Os like I said before. It seems to me that a MAX232 at $0.45 plus a 3.3->5V booster is more expensive than just using a MAX3232 at something like $1.65 (Estimate from Maxim web site).

You probabbly have a higher voltage in your system already and it would be way cheaper to make 5 volts from say +9 or +12 using a linear regualtor that it would be to boost 3.3V up to 5 volts swith some type of "crude inverter".

Michael Karas