geoRAM is a discontinued memory expansion unit designed to work with the

Commodore 64 The Commodore 64, also known as the C64, is an 8-bit computing, 8-bit home computer introduced in January 1982 by Commodore International (first shown at the Consumer Electronics Show, January 7–10, 1982, in Las Vegas). It has been listed in ...

and the

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computers. GeoRAM was specifically designed to work with the GEOS

operating system An operating system (OS) is system software that manages computer hardware and software resources, and provides common daemon (computing), services for computer programs. Time-sharing operating systems scheduler (computing), schedule tasks for ...

. geoRAM was created by Dave Durran. During the

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shortages of the 1980s,

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could not produce enough of its RAM Expansion Units (they eventually cancelled them). The GEOS

relied heavily on extra RAM and so the company behind GEOS produced their own memory expansion cartridge, called the geoRAM.13.3.2. What is a geoRAM Unit?
''When Commodore REUs became hard to find several years back, Berkeley Softworks introduced geoRAM, which is a 512K RAM expander. This RAM expander gives you all of the advantages of a 1750 with GEOS. However, it is not 1750 compatible, so it will not work like a 1750 outside of GEOS; it is transparent to other programs. (As a caveat on this, see the info on RAMLink)). DesTerm128 2.0 will not work with a geoRAM plugged in. A special version of GEOS 2.0 (which is bundled with geoRAM) is necessary to use geoRAM. No additional power supply is necessary to use geoRAM.'', COMP.SYS.CBM: General FAQ, v3.1 Part 8/9 By using a mapped-in page scheme, RAM contents on the cartridge are directly accessible by the CPU, and don't rely on

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like the REU cartridges, which enable memory transfers between system RAM and REU much faster than the system CPU can do. Hence, there's no other benefit than extra RAM, and not much software other than GEOS actually supported it.

References

Home computer peripherals Memory expansion Commodore 64 {{Microcompu-stub