[OS X TeX] magnification

[juan tolosa]

Sometimes I use \magnification\magstep1 to get larger printouts for quizzes and tests. This works very well in TexShop, in my mac. At work, however, I use a PC running mictex. Then the \magnification command is totally ignored, and I get a reduced size output, as compared to the one in the mac. Any suggestions on how to "force" mixtex to execute the \magnification command?

Thanks,
               Juan Tolosa