Support for MathTime 1.1 and MathTime Plus fonts in LaTeX 2e is
available in /macros/latex/packages/PSNFSS.  Look for the files
mathtime.dtx and mathtime.ins.  `TeX' the file mathtime.ins to create
mathtime.sty, then add \usepackage{mathtime} to your source file.
Run LaTeX on mathtime.dtx to obtain the printed documentation for
the package.  You will also need to change text fonts, perhaps by
using \usepackage{times}, and specify the text fonts encoding 
(e.g. T1 or LY1 or LM1). Otherwise the package defaults to assuming 
that  you are using T1 encoding.