INES Mapper 074: Difference between revisions
From NESdev Wiki
Jump to navigationJump to search
Rainwarrior (talk | contribs) m (iNES category sorting) |
(add notes to m074) |
||
| Line 3: | Line 3: | ||
It's identical to [[iNES Mapper 192]] and used for the same reason, except that only pages 8 and 9 are RAM. | It's identical to [[iNES Mapper 192]] and used for the same reason, except that only pages 8 and 9 are RAM. | ||
If the [[NES 2.0]] header is present, 74 and 192 should be emulated identically, as NES 2.0 specifies CHR RAM size elsewhere. | If the [[NES 2.0]] header is present, 74 and 192 should be emulated identically, as NES 2.0 specifies CHR RAM size elsewhere. | ||
Some games will be mis-headered as m074 but should really be m192 and will either need to be changed to the correct mapper, or changed to the correct amount of CHR RAM and handled by unified code. | |||
We could consider deprecating one of these mappers and re-specifying it to support either CHR RAM size. | |||
Here are Disch's original notes: | Here are Disch's original notes: | ||
Revision as of 20:55, 26 November 2012
iNES Mapper 074 is a MMC3 clone used in Eastern games. It's identical to iNES Mapper 192 and used for the same reason, except that only pages 8 and 9 are RAM. If the NES 2.0 header is present, 74 and 192 should be emulated identically, as NES 2.0 specifies CHR RAM size elsewhere.
Some games will be mis-headered as m074 but should really be m192 and will either need to be changed to the correct mapper, or changed to the correct amount of CHR RAM and handled by unified code.
We could consider deprecating one of these mappers and re-specifying it to support either CHR RAM size.
Here are Disch's original notes: ======================== = Mapper 074 = ======================== aka: -------------------------- Pirate MMC3 variant Example Games: -------------------------- Di 4 Ci - Ji Qi Ren Dai Zhan Ji Jia Zhan Shi Notes: -------------------------- This mapper is a modified MMC3 (or is based on MMC3?). In addition to any CHR-ROM present, there is also an additional 2k of CHR-RAM which is selectable. CHR pages $08 and $09 select CHR-RAM, other pages select CHR-ROM Apart from that, this mapper behaves exactly like your typical MMC3. See mapper 004 for details.
