A 256Kb RAM expansion for the CPC. This combined with the DkTronics 256Kb memory expansion (advertised as such) would give the CPC an additional 512Kb RAM in the case of a 464/664 or an additional 448Kb RAM in the case of the 6128 - ie: in all cases a maximum of 576Kb RAM.
Silicon Disc Versions
- "dk'tronics Silicon Disc" cartridge
- "dk'tronics Silicon Disc Operation System" cartridge
The difference here is probably, that the first cartridge contains plain RAM, the second additionally a BIOS ROM with RSX commands for accessing the RAM disc.
Other Versions
Dk'tronics also made the "Dk'tronics memory expansion". Not sure if/how it differs from the "Silicon Disc". Maybe it's just renamed and contains exactly the same hardware... or maybe one of the devices is battery-backed, and the other isn't...?
An article in Amstrad Action described how a Silicon Disk can be converted into a 256K memory expansion. I think this applies to the RAM part only.
Manual
- File:DKTronics Silicon Disk Manual.pdf - DK'Tronics User Manual (English)