You should know the basics of algebra and analysis: matrix manipulations, determinants, vector spaces, derivatives, integrals, differential equations.
You will need to be acquainted with code and data maintenance utilities such as make, RCS, FWEB, and HDF, as well as with Fortran-90 (F90) and High Performance Fortran (HPF).
You should know something about Emacs and Emacs Calc, Maxima (or Maple) and Octave (or Matlab), and, last but not least, you should know how to work with the Indiana University SP supercomputer, i.e., how to submit parallel jobs to Load Leveler and how to run them interactively, how to link subroutines from the PESSL library and from the HDF library with your HPF programs, and how to work with AFS on the SP and on the Ships cluster in the Student Building. Basic UNIX skills are a must.
If any of these are a novelty to you, you can learn about them by going through