[fpc-pascal] Simple question

[Peter H.M. Brooks]

This is probably a simple question and I ought to know the answer - but 
I don't!

Is there an object in Pascal (fpc, of course) that I can use like this:

1. Push things (bytes, asciistrings, integers ..) onto like a stack
2. Find the length of in bytes
3. Write out, or use generally, as an array?

I can write one as an object, but, if there already is such a thing then 
I'd rather use it than re-invent the wheel!