Join the growing ranks of Texas Instruments Compact Computer 40 owners who now have increased access to RAM storage on their machine. This CC-40 RAM cartridge replicates the functionality of the original 32kB RAM cartridge option and also expands it 4, 8 or 16 times to 128KB, 256KB, or 512KB. Easy access DIP switches on the rear of the unit allow one to select which 32kB bank is in use, and all banks are preserved with the optional 3V battery