Commodore Amiga 500 Plus
In the 1980s, Commodore made a newer version of their very popular Amiga 500, called the Amiga 500 Plus. It added a few things, namely newer versions of Kickstart and Workbench — both 2.04, 1MB of Chip RAM, and a motherboard-based Real Time Clock. The RTC was battery backed up, and is responsible for VARTA battery leaks. These batteries leak base (not acid, like most people assume) and this eats the PCB causing failures. There were also minor improvements of the custom chip sets, introducing the Enhanced Chip Set.