I think you ask one of the computers something like “If I asked you ‘Does the door on the right lead into Heaven?’, would you say ‘Yes’?”
Suppose the right-hand door really does lead into Heaven. In that case, the truth-teller naturally says “Yes.” If the liar had been asked ”Does the right-hand door lead to Heaven?”, it would have said “No”: so it must also answer you question with “Yes” in order to lie.
If the right-hand door goes to Hell, the truth-teller says “No.” If the liar had been asked simply “Does the right-hand door go to Heaven?”, it would have said “Yes”: therefore it must also say “No” to your question.
So, no matter which computer you ask, you can safely use the right-hand door if the answer is “Yes” and the left-hand door if it’s “No” – or the other way round, of course, if you think you’ll prefer the company in Hell.
Dilige et quod vis fac