GeoRAM

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Storage medium
GeoRAM
General
Type Memory expansion
capacity 512 kB RAM
origin
developer Berkeley Softworks
Launch 1991

GeoRAM is a memory extension designed by the American manufacturer Berkeley Softworks as a plug-in module for the 8-bit home computers Commodore 64 (C64 for short) and Commodore 128 (C128 for short). The memory expansion has a capacity of 512 kB and came on the market in 1991 as a replacement for the no longer manufactured Commodore RAM Expansion Units (REU for short) of the types 1700, 1750 and 1764. The GeoRAM takes its name from the graphical user interface GEOS , for which it was mainly designed. Apart from the GEOS operating system, GeoRAM was rarely used.

In contrast to the RAM expansion units from Commodore, GeoRAM does not have a DMA chip for direct memory access and can therefore not carry out the data transfer between its own and the on-board C64 or C128 working memory. Rather, a 256-byte memory block is displayed in the input / output area of ​​the C64 ($ DE00- $ DEFF), from which a corresponding program must copy the data itself. The memory block is selected via the addresses $ DFFE- $ DFFF, which were mirrored in the entire second input / output area. Programming is therefore very easy. The additional functions of the RAM expansion units from Commodore based on direct memory access, such as the fast moving or filling of memory areas, are not available under GeoRAM.

Since 2006 there has been a further development of GeoRAM called NeoRAM that can be expanded to up to 2 MB. It is used by fans of retrocomputing who prefer the original hardware to the C64 or C128 emulators operated on modern computers.

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