The Expert Cartridge by Trilogic
I do now if this was ever released in the USA or not. This was another memory snapshot cartridge.
Freezes – Freezes and saves programs to disk
One File – Programs are saved in one file
Compacts – Programs are compacted to reduce disk space used
Saves More – You can save 3 or more programs per disk
Not Needed – The cartridge is not needed for loading saves
Upgradable – The cartridge used RAM and disk based software for instant low cost upgrading
Monitor – Use the machine code monitor to cheat, gain extra lives, etc
Also for Tape to Disk backups
The cartridge was also reversed engineered and a reproduction was sold on Ebay.
For MORE information: The Expert Cartridge Project