Add-Ins (or Added Applications) are programs written in C++ which appear in the main menu. They allow to set up windows, graphical interfaces, menus, as in integrated applications. These programs are faster than those written in Basic but it's more difficult to learn C++ programing.
C++ is a compiled language, Add-Ins must be programmed on a computer, converted and be sent to the ClassPad 300 using ClassPad Add-In installer software. The software used to write Add-In programs is the ClassPad SDK which can be downladed on Official Website.
Important : ClassPad SDK is not supported by Casio. Casio does not answer any questions about the ClassPad SDK and Add-In programing.
Assembly language used by the ClassPad is the assembly SH-3, due to the type of processor used by the ClassPad. Assebly is the language the nearest of the "machine language"; thats its principal advantage (because it is faster than C++) but the inconvenience is that it is hard to be read and little handy : the realization of a complete program asks a lot of effort and experience. We generally use assembly to create some functions which are exported in a C++ program, for example when some calculations need to be executed very fast (screen refresh...).
Programing in assembly is reserved to good programers. This language only allows to do what the processor is capable of doing : read/write into memory and realize simple operation on its registry. Then, if we want simply show a pixel on the screen, we must know the address of the screen and its structure in memory, and "write" at this address in the right place (without altering nearby pixels). This language can also be dangerous : we have the possibility to make everything with the memory, a wrong manipulation can block the machine definitely.