Short answer; you can't. But you can purchase (or borrow) a TI84 calculator and use the TI83's transfer cable to transfer data from the 83 to the 84 to your mac computer (the TI84 comes with a USB transfer cable).
Games written for Mac OS X will work on a Mac. Games written for the Windows operating system will require the Windows operating system to be installed on a Mac to work. Some Windows games can be used on a Mac without Windows by using CrossOver Games software.
You will have to install Windows using Boot Camp.
A Mac does not have DOS Mode. To play games on a Mac you need a Mac OS X version of the game. Games made for the Windows operating system need to have the Windows operating system installed on your Mac to operate.
The Nancy Drew games are only available for computers using the Windows operating system and are not compatible with Mac OS X.
Yes. Installing Windows on your Mac using Boot Camp will allow you to play Windows games (subject to meeting system requirements like processor, graphics, RAM, etc...).
Yes, by using CrossOver Games.
Apple computers, in common with most other computers, can play video games.
If you install Windows XP or Vista using Boot Camp, yes. You cannot play them in Mac OS X unless you purchase the Mac version.
Software is written to work with a particular operating system. Games written to work with Mac OS X will not work on computers using the Windows operating system and vice versa.
It is not that the mac cannot play certain games. It is that the games are not written to by played on a mac. The software developers choose not to write a version that is compatible with mac.
The games will need to be written for Mac OS X to run on a standard Mac. If the games were written for the Windows operating system then Windows have to be installed on the Mac for them to work.