what is accurate sense?

[sweetaish]

Hello,I need to know what is the most accurate sense of the sentence" what's up" Actually it is usally taken two sense, like it means ''What have you done today:
Jack: Hello Robert, what's up?
Robert: Hi Jack, oh not much. I played football today.
Simutaneously, it is used to ask"what's going on"
Jack: Hello Robert, what's up?
Robert: Hi Jack, oh not much, i am just doing my assignment.
I am actually confused about the tense.
May i also know that if we can use "would" as "used to", and how we can avoid its repitation as in the foloowing passage:
" i have a great respect for my father's profession Actually when he used to go to work , i also used to go with him. I used to look at him doing his work. I really used to like the smell of the newly built houses" {In fact, if we use past tense instead of "used to" it indicates that the activity took place in the past but it doesn't indicate that the activity took place gradually or it was a routine}
Thanx.

[mykwyner]

In colloquial American English, What's up? or Wazup? or (t)Zup? or What's happening? or How's it going? etc. are greetings like What's new?, or How are you?. They are not intended to solicit information. The answer to all the What's... questions should be "Nothing" or "Not much." The answer to the How's... questions should be "O.K."

In your paragraph I would use the simple past more. It works great if that is what you're trying to say. I sometimes went to work with my father. I watched him work. I liked the smell...

[sweetaish]

Thanks for solving my confusion. Now i can confidently reply to such questions.
yeah You are right, if we use " sometime" or "regulary", the sense i want to convey could be conveyed far better. thaks once again