# Commodore REU > memory expansion technology **Wikidata**: [Q2124010](https://www.wikidata.org/wiki/Q2124010) **Wikipedia**: [English](https://en.wikipedia.org/wiki/Commodore_REU) **Source**: https://4ort.xyz/entity/commodore-reu ## Summary The Commodore REU (Ram Expansion Unit) is a memory expansion peripheral developed by Commodore International in 1985 for Commodore 64 and Commodore 128 computers. It provided additional RAM storage in 128KB, 256KB, or 512KB capacities to overcome the base systems' memory limitations. ## Key Facts - **Commercialization Date**: 1985 - **Manufacturer**: Commodore International - **Target Platforms**: Commodore 64, Commodore 128 - **Storage Capacities**: 128KB, 256KB, and 512KB variants - **Product Classification**: Instance of "product model"; subclass of "peripheral" - **Aliases**: REU, Ram Expansion Unit, RAM Expansion Controller, コモドールREU, Commodore RAM Expansion Unit - **Documentation Languages**: German, English, Spanish, Hungarian, Italian - **Sitelink Count**: 5 (across Wikimedia projects) - **Freebase ID**: /m/03bqns - **C64 Wiki ID**: REU - **Wikidata Description**: Memory expansion technology ## FAQs ### Q: What is the Commodore REU? A: The Commodore REU is a hardware peripheral that added 128KB, 256KB, or 512KB of external RAM to Commodore 64 and 128 computers, enhancing their memory capabilities beyond factory specifications. ### Q: Which computers supported the Commodore REU? A: It was designed exclusively for the Commodore 64 and Commodore 128 platforms, connecting via their expansion ports. ### Q: When was the Commodore REU released? A: It was commercialized by Commodore International in 1985, coinciding with the peak era of Commodore 64 popularity. ### Q: What storage capacities did the REU offer? A: Three variants were available: 128 kilobytes (KB), 256KB, and 512KB, allowing users to choose based on performance needs and budget. ### Q: How is the REU classified? A: It is an instance of "product model" and a subclass of "peripheral," categorizing it as an add-on hardware device for expanding computer functionality. ## Why It Matters The Commodore REU addressed critical memory limitations in the 1980s home computing era, enabling more complex software, larger datasets, and advanced graphics applications on Commodore systems. By providing up to 512KB of additional RAM—more than doubling the Commodore 64's native 64KB—it empowered users to push the boundaries of gaming, productivity, and programming. This expansion technology preserved the relevance of aging hardware during the transition to more advanced machines, extending the lifespan of Commodore platforms and fostering innovation among hobbyist developers. ## Notable For - **Memory Expansion Leadership**: One of the earliest dedicated RAM expansion units for 8-bit home computers, pioneering memory augmentation techniques. - **Platform-Specific Design**: Optimized exclusively for Commodore 64 and 128 systems, leveraging their unique hardware architecture. - **Multi-Capacity Variants**: Uncommon flexibility in offering three distinct storage tiers (128KB/256KB/512KB) to match diverse user requirements. - **International Documentation**: Multilingual support (German, English, Spanish, Hungarian, Italian) reflecting its global distribution and adoption. - **Peripheral Classification**: Classified under the broader "peripheral" category, emphasizing its role as an essential add-on for extending computer capabilities. ## Body ### Overview The Commodore REU (Ram Expansion Unit) is a hardware peripheral designed to augment the memory of Commodore 64 and Commodore 128 computers. Released in 1985 by Commodore International, it directly countered the memory constraints of these systems by providing external RAM storage in three capacity variants. ### Technical Specifications - **Storage Options**: Available in 128KB, 256KB, and 512KB configurations, with the 512KB model offering eight times the native Commodore 64 RAM. - **Compatibility**: Exclusively supported Commodore 64 and Commodore 128 platforms, utilizing their dedicated expansion ports for connectivity. - **Functionality**: Served as a standalone memory expansion unit without overlapping roles like input/output or storage, focusing solely on RAM augmentation. ### Development and Release - **Manufacturer**: Produced by Commodore International, the same company behind the Commodore 64 and 128. - **Launch**: Commercialized in 1985 during the Commodore 64's market dominance, extending its utility for power users and developers. - **Legacy**: Retains historical significance as a representative peripheral from the 8-bit home computer era. ### Naming and Localization - **Aliases**: Known internationally as REU, Ram Expansion Unit, RAM Expansion Controller, コモドールREU (Japanese), and Commodore RAM Expansion Unit. - **Multilingual Support**: Documented in five languages (German, English, Spanish, Hungarian, Italian), underscoring its global adoption. ### Product Classification - **Hierarchy**: Classified as a "product model" and a direct subclass of "peripheral," placing it within the broader category of computer add-ons. - **Peripheral Attributes**: Inherits core traits from the peripheral class—such as external connectivity, hardware extension, and functionality augmentation—while specializing in memory expansion. ### Ecosystem Integration - **Platform Synergy**: Designed specifically for Commodore 64/128 expansion ports, ensuring seamless integration with existing hardware. - **Peripheral Ecosystem**: Operated alongside other Commodore peripherals (e.g., floppy drives, printers) as part of the company's modular hardware strategy. ### Community and Documentation - **Online Presence**: Maintains 5 sitelinks across Wikimedia projects, including Wikipedia (in multiple languages) and the C64 Wiki (ID: REU). - **Archival References**: Preserved in digital archives such as Wikimedia Commons, with imagery showing the hardware in operational use. ### Historical Context - **Memory Expansion Era**: Emerged during a period when RAM scarcity severely limited software complexity, making such add-ons critical for enthusiasts and professionals. - **Impact**: Enabled advanced applications like larger games, professional development tools, and memory-intensive data processing, extending the Commodore platform's viability into the late 1980s.