Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See page_maxonapi_getting_started_foundations_cinema_parameters.
Parameter: Undo Depth
PREF_MEMORY_UNDO
Parameter: Animated Materials (MB)
PREF_MEMORY_MATERIAL
Parameter: Displacement (MB)
PREF_MEMORY_RENDERER
Parameter: Texture Undo (MB)
PREF_MEMORY_BP
Parameter: Min Undo Steps
PREF_MEMORY_BPUNDO
Parameter: Memory (MB)
PREF_MEMORY_PVUSEAGE
Parameter: Hard Drive (MB)
PREF_MEMORY_PVHARDUSAGE
Parameter: Unlimited
PREF_MEMORY_PVHARDUNLIMIT
Parameter: Cache Path
PREF_MEMORY_PVHARDFOLDER
Parameter: Memory (MB)
PREF_MEMORY_SCULPTUSAGE
Parameter: Max Footage Cache (MB)
PREF_MEMORY_PHFOOTAGEMAXCACHEMB
Parameter: Min System Reserve (MB)
PREF_MEMORY_PHFOOTAGESYSRESERVEMB