The German 4.0 rev is based on the A1000 chipset (DIL Agnus, OCS, 512 KB chip RAM, different CPU slot, no composite output). >=4.1 are from West Chester with the A500's chipset (PLCC Agnus, OCS or ECS, up to 1 MB chip RAM, standard CPU slot, composite video, Buster), rather minor differences.
