GRAM/1D - 1MB geoRAM clone for Commodore 64/128
The geoRAM is a 512KB memory expansion for the Commodore 64 and 128 designed by Berkeley Softworks for use with GEOS. While not as fast as the Commodore REU due to its lack of DMA capabilities, it still provides a significant performance boost. GRAM/1D is a 1MB geoRAM compatible cartridge based on a two 1Mx4 DRAM devices.