1980s computer tech is a massive joke. Necessary, it had to have happened, it obviously took genius, but by today's standards a little embarrassing. Melanie with her degree in Computer science circa 1985 should have had about as much luck trying to fix an alien super computer as Jamie or Leela. 
I'm listening to the new Audio with 7 and Melanie, and he's giving Mel fantastic accolades as a computer genius without equal who needs to root about and fix an alien super computer which is on the blink.
Hmmm?
The TARDIS telepathic translation circuits take alien languages and turn them into English, or more accurately probably is that everyone speaks Gallifreyan, but really every bugger thinks that everyother bugger is speaking something familiar...
Programming Code is a language.
The TARDIS is probably translating alien computer code/language into C++ or Paradox or Perl for Melanie, and then back again into Alien as she tries to express herself with C++ or Paradox or Perl.
Training wheels much?

I'm listening to the new Audio with 7 and Melanie, and he's giving Mel fantastic accolades as a computer genius without equal who needs to root about and fix an alien super computer which is on the blink.
Hmmm?
The TARDIS telepathic translation circuits take alien languages and turn them into English, or more accurately probably is that everyone speaks Gallifreyan, but really every bugger thinks that everyother bugger is speaking something familiar...
Programming Code is a language.
The TARDIS is probably translating alien computer code/language into C++ or Paradox or Perl for Melanie, and then back again into Alien as she tries to express herself with C++ or Paradox or Perl.
Training wheels much?