IF they can make Operating Systems in FPC like DelphineOS and others why wouldn't they be able to make drivers, in Linux driver making seems not to be verry hard, in windows you can make drivers even in old Borland C, how ? .. well it's a simple dll renamed as sys and you call your code from there, also check out ZLPortIO wich has a multi porpose driver 3 KB or so, you can even access hardware without any drivers using callgates and such, depending on what you plan to do you have multiple choices:
Serial Access - Lots of components for Delphi and FPC, check Synaser for example.
Paralell access use ZLPortIO for win32 and libs for Linux.
USB access even 2.0, use HID from JEDI or even better libusb wich is ported to win32 too, lod_ (the guy from IRC) made himself a header using h2pas to use with lasers and those kind of devices.

There is no limit to what Pascal can do, you just have to love the language and serch for how to do it, personally i didn't find yet any language that is a good as Object Pascal in terms of syntax quality, IDEs, and overall speed and capabilities, there are many new languages that have certain features from Pascal or Java like .NET but nothing compares to the real thing, lately i even discovered you can write web pages in Pascal instead of PHP using PSP(Pascal Server Pages), you just make a small executable and put it in Apache's cgi-bin folder and there you have it, interactive webpage made with Pascal wich you can uplod to sourceforge for example, PasWiki uses PSP.

The fans of other languages and Pascal beginers often think that Pascal is not powerful, please tell me one thing that Pascal can't do and i'm pretty sure there is a way to do even that