Dk'tronics Silicon Disc

Box and Manual for the memory expansion (464 version)

A closeup of 6128 version

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.

• "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.

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. [which article is that?]

• The 64K silicon disc is contained in one unit (Operating system ROM), while the 256K silicon disc is in two units (256K RAM and Operating system ROM).
• When the computer is powered up the ROM should sign itself on as:-
  • 'Silicon Disc 0.1' (for use with 64K BANKED RAM)
  • 'Silicon Disc 1.1' (for use with 256K BANKED RAM)
• Remember the contents of the silicon disc are lost if the computer is switched off!
• 64K Silicon Disc: OUT &7F00, &C4+BANK  ;where BANK is 0..3
• 256K Silicon Disc: OUT &7F00, &E4+(BANK AND 3)+(BANK/4)*8  ;where BANK is 0..16

• Media:DKTronics_Silicon_Disk_Manual.pdf - DK'Tronics User Manual (English)

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  Circuit Board