Hi.
The following demo's from
Amiga Demo Archive, should work fine on a vanilla A1200.
Andromeda - Nexus 7
Complex - Origin
Complex - Real (maybe)
Polka Brothers - Friday at eight
Polka Brothers - Gevalia
Polka Brothers - The Prey (might require harddrive)
Polka Brothers - Noname
Rebels - Switchback
Virtual Dreams - Love
Virtual Dreams - Fullmoon
ps. working from memory here :-)
