Turbo Pascal was the first language in which I had serious classes (I had tutoring in Applesoft Basic earlier on, but that language has a lot of limitations), and I used it for years afterwards. You could write auxiliary functions in Turbo Assembler and link them in; I used that to write a library that allowed access to the 320x200 256-color VGA mode (the built-in graphics only did EGA and were super slow), and other libraries for mouse and joystick control. I tried to control the soundblaster for FM synthesis, but it was too complicated for me to figure out how to do anything useful without better access to documentation (this was before the world wide web). The experience also taught me a lot about assembly language basics, function calling conventions for C and Pascal, stack manipulation, and so forth, which gave me a huge head start in my compilers courses at university.
On the whole I would still recommend C over Pascal as an early language--it gives you much better insight into memory layout and so forth, where Pascal kind of obfuscates such things, and C just generally kind of acts like both Pascal and Assembler rolled together. But Turbo Pascal definitely gave me a good foundation.