Q: "How did NASA create these images with the computer technology available at the time?"
A: Since NASA did not send rockets into space, they instead spent the money on developing advanced computers and imaging software instead
There's a failure to note that when Man (supposedly for those non-believers/heretics =P) first stepped on the moon, computer software had just come out of the magnetic tape era, there was nothing advanced about the imaging software then.
Take a look at history between 1900 and 2000, the first pictures of the earth was about the sixties, the first computers within the couple decades before, computer power doubles about every... what was it... 18 months (if I remember correctly). Think long and hard about this one... long... and hard... Your conspiracy doesn't hold water here.