Problems with dialup and "outside lines"

Hullo all, any help here is much appreciated. I'm in a university hall of residence that isn't networked (!) and I need to sort dialup out to connect from my room. The problem is that the phoneline in question has an odd dialtone for internal calls that pppd doesn't recognise as a dialtone, and the "proper" one only comes on after you key in a security code. So whenever I try to dial in, I get "NO DIALTONE". I've tried mucking around with the modem by using the terminal in Kppp, but with no luck. It doesn't seem to want to start dialling a number until I type in "ATDT", but that checks for a dialtone, which of course then fails.

How do I get the security code in before checking for a dial tone and dialling in?

P.S. ppp worked fine at home, so it's nothing wrong with my set-up in terms of tools, modules etc.

"ATX0" will shut off busy detection (actually some more stuff too). also look for a "X1" or "X3" in the init string to remove it or it could override your settings.

you can make the modem pause using a comma in your dial string, each will be 0.5 sec iirc. so you dial string is: atdt<code>,,,,,<number>

or to make sure you override all other settings:
atx0dt<code>,,,,,<number>

Thanks, I'll give it a go.