The EPROM (Erasable Programmable Read Only Memory) chip is a powerful tool in the programmer's arsenal. These chips hold your own programs or code on a cartridge. They can even be used as custom replacements for standard chips that come with the computer.

EPROMs come in several capacities, usually in multiples of 4K (16 CBM disk blocks). The hardware required for customizing and using them is relatively inexpensive and easy to use. It consists mainly of an "eraser," for reinitializing EPROMs during the process of program development, and a "burner," or programmer for putting your code into the chips.

There's a wide variety of cartridge formats for the 64. Some cartridge boards are little more than ROM/EPROM sockets on a plug-in card, while others are sophisticated enough to have their own logic elements. The possibilities vary widely.

For more information about EPROM and cartridge availability and price, as well as devices such as EPROM erasers and burners, write to Jason-Ranheim, 580 Parrott Street, San Jose, California 95112.