 The PCjr-compatible version of Lotus 1-2-3 comes on two cartridges and a floppy disk.ROM cartridges are typically more expensive to manufacture than discs, and storage space available on a cartridge is less than that of an optical disc like a DVD-ROM or CD-ROM.Techniques such as bank switching were employed to be able to use cartridges with a capacity higher than the amount of memory directly addressable by the processor.