I am sure many of you have encountered the mysterious “Garbage Collection” screen (pictured on the right). In this article, the Garbage Collection feature of the TI-83 Plus, TI-84 Plus, and TI-84 Plus Silver Edition Calculators will be explained.
What is Garbage Collection? Well, in order to explain that, you will have to know how the calculator stores information.
The calculator memory is broken up into multiple “Segments”. When you first buy your calculator, and then upload a program, the program is inserted into “Sector 1”. Each program will vary in size, so often, you end up needing more space than what is left in the sector. This means that the variable or program will be loaded into the next sector, as the sectors can not change in size.
Eventually, all of the sectors will have small holes, in which large programs do not fit. When this happens, you need to Garbage Collect.
Garbage Collection is when the calculator rearranges all of the blocks of data, so they all fit into the sectors. In addition, when you unarchive a program, it is just copied into the RAM, but not actually deleted from the archive. This will leave two copies of the program on the calculator. However, Garbage Colleting will clear up some memory by deleting the extra copy in the archive, which will free up blocks of memory for other programs.
If you ever want to free up some space on your calculator, you can call the Garbage Collect command from the catalog. You can access the catalog by pressing the [2ND] key, then the  key. Once the menu is displayed, you can scroll down to the command. When “GarbageCollect” is highlighted, press the enter key. Now, press enter again to execute the command and display the Garbage Collect menu.
Please note, Garbage Collection may take anywhere from seconds, to minutes, or even up to a half-an-hour, but after you Garbage Collect, you might notice a speed difference– your calculator might seem faster.