It's always preferable to post the full clues, numbers of letters & any you've placed, so that people without the puzzle can more readily help you - thanks for next time! :-)
That said, & assuming you mean the Sun Tel Cryptic 2600 (?) -
4d Wed heartless lady to a man (8) - United-l(ad)y
12a Chemist, short of cash, began using computer (12) - Boot-strapped