NEO-PVC: Difference between revisions
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[[File:brd_pvc.jpg|thumb|NEO-PVC chip. Picture courtesy of [[http://www.mvs-scans.com MVS-Scans]].]] | [[File:brd_pvc.jpg|thumb|NEO-PVC chip. Picture courtesy of [[http://www.mvs-scans.com MVS-Scans]].]] | ||
QFP144 chip connected to the [[ | QFP144 chip connected to the [[P ROM]]s in [[ROM-Only boards|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 [[http://mamedev.org/source/src/mame/machine/neoprot.c MAME's source]]: | |||
Accesses are made in the $2FE000~$2FFFFF range: | |||
<pre> | |||
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); | |||
</pre> | |||
[[Category:Chips]] | [[Category:Chips]] | ||
Revision as of 23:39, 29 March 2012
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);