A ROM cartridge, sometimes referred to as a cart, is a removable enclosure containing read-only memory devices designed to be connected to a computer or games console.
ROM cartridges can be used to add additional functionality or content to the host machine, hardware additions like speech synthesis, or software such as video games.
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ROM cartridges were popularized by early home computers which featured a special bus port for the insertion of cartridges containing software in ROM. In most cases the designs were fairly crude, with the entire address and data buses exposed by the port and attached via an edge connector; the cartridge was memory mapped directly into the system's address space.
Notable computers using cartridges in addition to magnetic media were the Commodore VIC-20 and 64, the Atari 8-bit family (400/800/XL/XE), the Texas Instruments TI-99/4A (where they were called Solid State Command Modules and were not directly mapped to the system bus) and the IBM PCjr (where the cartridge was mapped into BIOS space).
From the late 1970s to mid-1990s, the majority of home video game systems were cartridge-based. The first system to make use of ROM cartridges was the Fairchild Channel F.[1] As compact disc technology came to be used widely for data storage, most hardware companies moved from cartridges to CD-based game systems. Nintendo remained the lone hold-out, using cartridges for their Nintendo 64 system; the company did not transition to optical media until 2001's GameCube.
Personal computers which used cartridges include the Atari 8-bit family, the IBM PCjr,[2] and the Commodore family of systems.[3]
Game systems that used cartridges include:
ROM cartridges can not only carry software, but additional hardware expansion as well. Examples include the Super FX coprocessor chip in some Super Nintendo games, and voice and chess modules in the Magnavox Odyssey².
Micro Machines 2 on the Sega Megadrive used a custom "J-Cart" cartridge design by Codemasters which incorporated two additional gamepad ports. This allowed players to have up to four gamepads connected to the console without the need for an additional third-party adaptor.
Storing software on ROM cartridges has a number of advantages over other methods of storage like floppy disks and optical media. As the ROM cartridge is memory mapped into the system's normal address space, software stored in the ROM can be read like normal memory; since the system does not have to transfer data from slower media, it allows for nearly instant load time and code execution. Software run directly from ROM typically uses less RAM, leaving memory free for other processes. While the standard size of optical media dictates a minimum size for devices which can read disks, ROM cartridges can be manufactured in different sizes, allowing for smaller devices like handheld game systems. And while ROM cartridges can be damaged, they are generally more robust and resistant to damage than optical media; accumulation of dirt and dust on the cartridge contacts can cause problems, but cleaning the contacts with an isopropyl alcohol solution typically resolves the problems without risk of corrosion.[4]
However, ROM cartridges are typically more expensive to manufacture than disks, and storage space available on a ROM cartridge is less than that of an optical disk like a DVD-ROM or CD-ROM. As video games became more complex (and the size of their code grew), software manufacturers began sacrificing the quick load time of ROM cartridges for the greater capacity and lower cost of optical media.[5][6]