Gemini
From CPCWiki - THE Amstrad CPC encyclopedia!
Gemini is an 1MB or 2MB RAM expansion for CPC 6128 or Amstrad Plus.
It uses a 1MB RAM chip and Atmel ATF22v10 chips (direct successor of the PAL used by Amstrad for the CPC6128).
Unlike other memory expansions, Gemini tracks the ASIC unlocking and mapping, and disables itself for the 4000-7FFF range when the ASIC is mapped there. This avoids memory corruptions for software that uses the ASIC and extended memory at the same time.
