How the Commodore REU Works
The 8-Bit Guy・13 minutes read
Commodore 128 introduced in 1985 was expandable to 512k but later released expanders increased RAM capacity for C128 and C64, offering improved performance and storage options. The REU by Commodore served as an ultra-fast storage device, enhancing data copying speed and significantly boosting capabilities of C64 games utilizing extra RAM for better graphics and gameplay.
Insights
- The Commodore 128, despite being advertised as expandable to 512k, could actually only be expanded to 256k or 640k, not the initially promised 512k, which led to challenges in upgrading due to space limitations in the cartridge port.
- The REU (RAM Expansion Unit) by Commodore served as an ultra-fast storage device, not just a RAM expander, significantly enhancing data copying speed through its block copy function, which moved data rapidly, contrasting with the CPU's slower byte copying process. The REU not only improved performance on GEOS for C128 but also boosted the capabilities of C64, enabling enhanced graphics and gameplay in games like Sam's Journey, Sonic the Hedgehog, and Pesky Robots.
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Recent questions
What is the purpose of a RAM expander?
A RAM expander is a device used to increase the amount of random access memory (RAM) available to a computer, allowing for improved performance and the ability to run more complex programs.
How does a RAM expander enhance data copying speed?
A RAM expander functions as an ultra-fast storage device that can rapidly move data using its block copy function, which contrasts with the slower byte copying process performed by the computer's CPU. This enhancement in data copying speed can significantly improve overall system performance.
What are the benefits of expanding RAM on a Commodore 128?
Expanding RAM on a Commodore 128 can lead to increased capabilities, as the computer can be expanded to either 256k or 640k, surpassing the initially advertised 512k limit. This expansion allows for running more advanced programs and improving overall performance.
How does a RAM expander impact GEOS performance on a Commodore 128?
A RAM expander can significantly enhance GEOS performance on a Commodore 128 by providing additional memory for running the graphical operating system more smoothly and efficiently. This boost in performance can lead to a better user experience and increased productivity.
Which games support the use of a RAM expander for improved graphics and gameplay?
Three games that support the use of a RAM expander for enhanced graphics and gameplay are Sam's Journey, Sonic the Hedgehog, and Pesky Robots. These games utilize the extra RAM and DMA copy capabilities provided by the expander to deliver a more immersive gaming experience with improved visuals and performance.
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Summary
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Commodore 128 RAM Expansion and Benefits
- Commodore 128 introduced in 1985, advertised as expandable to 512k but not achievable at launch.
- In 1986, a 1750 RAM expander with 512k for C128 and a 1764 RAM expander with 256k for C64 were released.
- Three official REUs by Commodore, two for C128 and one for C64, interchangeable but power supply compatibility crucial.
- C128 could be expanded to 256k or 640k, not 512k; light beige color matching C128 and 64c.
- Expanding RAM on C64 or C128 challenging due to lack of space in the cartridge port.
- REU functions as ultra-fast storage device, not a RAM expander, enhancing data copying speed.
- REU's block copy function moves data rapidly, contrasting with CPU's slower byte copying process.
- REU used for utility disk, diagnostics, RAM disk, spinning globe demo, and copy programs like Maverick.
- REU enhances GEOS performance on C128 and significantly boosts C64's capabilities.
- Three games supporting REU: Sam's Journey, Sonic the Hedgehog, and Pesky Robots, utilizing extra RAM and DMA copy for improved graphics and gameplay.
