Re: .. never used .. ?
Turbo Pascal was brilliant - particularly its object-orientated add-ons.
I wrote a simulator for an X.25 network using it, and it made the job really easy - I just made each switching node an object and you could construct large networks with ease, simply by creating a new node object and linking it to its neighbours. Brilliantly easy.
It worked so well that the figures I produced for new nodes being rolled out on the network we managed were so accurate that, when one wasn't performing within the time my model predicted, they called the Bundespost PTT to complain, and had the line fixed until it matched my figure, rather than complaining, as I'd expected, to me, that my numbers were wrong.
It was all a mistake, really. At a meeting our customer asked if we could produce projected performance figures, and, without thinking, we foolishly agreed - both my colleague and I thinking the other had a solution.
We should really have gone back and explained that predicting terminal performance was impossible - the maths boffins assured me that it was, because queuing theory wasn't good enough for a multiple node network. Still, I had my newly purchased Turbo Pascal, and thought it worth a try. It was hard work, but I had the figures to them within ten days.