NEO-PVC

NEO-PVC chip. Picture courtesy of [MVS-Scans].

QFP144 chip connected to the P ROMs in ROM-only arcade boards and late cartridges like SVC Chaos or Samurai Shodown 5. Used for bankswitching and security.

Has 8KiB of integrated RAM organized as 4096 16bit words.

From [MAME's source]:

Accesses are made in the $2FE000~$2FFFFF range:

	COMBINE_DATA(&state->m_pvc_cartridge_ram[offset] );
	if (offset == 0xff0)
		pvc_prot1(space->machine());
	else if(offset >= 0xff4 && offset <= 0xff5)
		pvc_prot2(space->machine());
	else if(offset >= 0xff8)
		pvc_write_bankswitch(space);