The 1MB iRAM internal RAM expansion for the CPC 6128 is finally finished and working.
It will be released on Github later this year.
Unlike the iRAM 640 it requires the SRAMs to be in SMD format, but they are quite easy to solder so it should still be DIY friendly
The very first expansion that I have built for documentation and testing purposes (basically the item #1) is now available on Ebay (starting at 1€) and I will ship to anywhere in the EU.

As promised, the internal 1MB RAM expansion iRAM/1024 for the CPC 464 and 664 is in development. The (hopefully) final prototype is in test now and so far everything works.
It gives you up to 1MB of total RAM and supports C3 mode (needed for some 6128 specific applications, games and demos like CP/M plus, Future OS or PacMan emulator).
As with the iRAM/640 for the 6128, it will be pure plug&play. Open the CPC, remove the CPU and put it into the socket on the iRAM. Then place the iRAM into the CPU socket on the motherboard. And voilà, enjoy up to 1MB of total RAM.
It will be still a few more weeks until the tests are finished. Once this is done it will be released on GitHub (for DIY projects) - and probably you can find it sooner or later on Ebay.