Its RIP software with one P. Stands for Raster Image Processor. Simply put, it is usually always a 3rd party printer driver that will process out the image going to the printer in a different way than the Manufacturers's supplied driver can.
There is nothing wrong with the supplied printer software / driver, but a RIP usually offers other option not available. In your case and need, a longer image size.
Normally a RIP is used to breakdown the color of CMYK files, which desktop color inkjet printers do not like to use print from, as their source colorspace, then rewrites it ( in the background without affecting the original file or image ) into a file that the printer can process.
Normally again, and to utterly simplify, a RIP on a desktop printer, is used to proof CMYK outputs ( press outputs ) before going to Pre$$.
Strangely enough, even though your printer uses cmyk inks, it is still considered an RGB device to the software driving it.
This is an overly simplified explaination of RIP software, but it provides the answer you are looking for.
I have used this product for:¬†less than a week
I use this product for:¬†Business