Different types of LaTeX fonts?

I noticed that Griffiths' elementary particles book uses a different type of font in math typesetting, akin to pre-LaTeX era (the one as in Feynman Lectures on Physics or Mary Boas' Mathematical Methods in the Physical Sciences), instead of usual LaTeX. Check out the attachement se-griffiths.jpg, it's Schrödinger equation from that book. I also added latex version of it (latex.png). Notice how different the psi and hbar is.

So, anyone knows how to "emulate" the Ye Olde Typesetting in LaTeX? Do I need some additional packages or what?

Thanks in advance

(I couldn't found the proper place for this post, so I'm trying to write to least irrelevant place. I hope it's OK)