You have a nice, decent sized 20GB hard drive in your new iMac... but you notice that only 10GB is left! Yes, you did install a number of programs- but not 10GB worth. Or you may have an old Performa with a 1GB hard drive and find you only have 50MB left. What happened to all that space? Well, the truth is that you probably have many duplicate files on your hard drive. How many? It's hard to say, but there are a few common things to look for.

Since Mac OS 8.0, the Mac OS has featured something seen in Windows since as long as I can remember. Contextual menus. These are menus that can be brought up virtually anywhere by clicking the right mouse button (on a PC), or by holding down the control key and clicking the mouse button.

Starting with the original Macintosh system software, key commands were available to speed up your work in the OS. However, they were not really fine tuned until System 7.x and the introduction of several new commands such as "make alias" (System 7.1.2). Many of the key commands from System 7 or 6 are still used in the latest Mac OS, version 10.1.

So, what are some of the key commands that might be considered useful?

Starting in the late 1980's, people have been able to take their computing with them on the road. Computers appeared with all different types of screens (most unusual was the original Compaqs, which used a special red display- instead of being shades of grey, it displayed shades of red), disk drives, and of course, batteries.

Starting with the original laptops, battery power was important because it allowed you to use your laptop in places where there is no electrical power, such as on an airplane.

So, where do you start? How about with a NuBus Power Macintosh. You have basically two choices if you want to add anything at all to your system. These choices are the 7100 series or the 8100 series. The 7100 is a desktop machine, with a single hard drive bay, a CD-ROM drive bay, a floppy drive, 3 NuBus slots, and one PDS slot. The 7100 has 4 RAM slots and 8MB built in to the logic board. The 8100 is a minitower Mac, and has 2 hard drive bays, one capable of holding a full-height drive. The 8100 also has 8 RAM slots, 8MB on the logic board, 3 NuBus slots, and one PDS slot.