Assembly: help convert upper to lower case

I am new to this and am stuck. I need to...

Convert all lowercase letters to uppercase
Convert any vowels (a, e, i, o, u) to lowercase
Convert any digits 0-9 to the letters P-Y

All conversions must be done using just the AND, OR, and NOT instructions

Here is the string:
"SoMe Of ThIs TeXt Is ReAlLy MeSsEd Up -- 2006",0

Also if you know of any good sites to learn assembly could you let me know.

Thanks

If this is with just ASCII then look at the difference in codes for upper and lower case letters ... notice they are 32 apart ... that is hex 20? Just (un)set that bit to coerce a case change.

I would suggest soemthing similar with the numeric to alpha problem you have - look at the pattern of bits involved inthe underlying ACSII representation.

And, as this smacks of a 'school project', I will leave you with just that ...