INES Mapper 136: Difference between revisions
From NESdev Wiki
Jump to navigationJump to search
NewRisingSun (talk | contribs) (MGC-008/MGC-010/MGC-011 use the 24-pin ASIC and should therefore pedantically be listed under 132, even as they would run under 136 as well.) |
NewRisingSun (talk | contribs) No edit summary |
||
| Line 30: | Line 30: | ||
==Similar Mappers== | ==Similar Mappers== | ||
* Mapper 136 is almost identical to [[INES Mapper 132]] with only 32 KiB PRG-ROM except in the value read from $4100 due to Mapper 136 having four (28-pin JV001 ASIC) versus Mapper 132 having three adder bits (24-pin 05-00002-010 ASIC). | * Mapper 136 is almost identical to [[INES Mapper 132]] with only 32 KiB PRG-ROM except in the value read from $4100 due to Mapper 136 having four (28-pin JV001 ASIC) versus Mapper 132 having three adder bits (24-pin 05-00002-010 ASIC). | ||
* [[Mapper 172]] is similar to Mapper 136, connecting the six CPU bits in reverse order due to the JV001 ASIC being mounted upside down. | * [[INES Mapper 147]] expands CHR-ROM size to 128 KiB and additionally supports 128 KiB PRG-ROM, switched in 32 KiB amounts. | ||
* [[INES Mapper 172]] is similar to Mapper 136, connecting the six CPU bits in reverse order due to the JV001 ASIC being mounted upside down. | |||
==See also== | ==See also== | ||
* [http://forums.nesdev.org/viewtopic.php?f=3&t=15961&start=30#p210702 PCB image] | * [http://forums.nesdev.org/viewtopic.php?f=3&t=15961&start=30#p210702 PCB image] | ||
Revision as of 12:00, 9 February 2018
INES Mapper 136 is used by three original (pre-Sachen) releases from Joy Van:
- 未来小子 (Wèilái Xiǎozi, "Joy Van Kid", original Taiwan release of Metal Fighter µ with Chinese title screen) (TC-008)
- 蝶變 (Diébiàn, "Incantation", original Taiwan release of Galactic Crusader with Chinese title screen, often incorrectly rendered as Japanese "Chou Hen") (TC-009)
- 四川麻將 (Sìchuān Májiàng, "Mahjong Trap", original Taiwan release of Shisen Mahjong - Seifuku Hen) (TC-010)
Banks
- PPU $0000-$1FFF: 8 KB switchable CHR ROM bank
Registers
Mapper 136 uses a custom IC (real number "JV001", fake marking "GS63030-A") serving as a latch, adder and inverter. There are five registers: Input (6 bits), Output (6 bits), Register (6 bits), Mode (1 bit) and Invert (1 bit).
Mask: $E103
Read $4100-$4103: [..RR RRRR]: Read Register. Bits 4-5 are inverted if Invert==1. Bits 6-7 are open bus.
Write $4100: When Mode==0: Bits 0-5 of Register := Input, bits 0-3 being inverted if Invert==1.
When Mode==1: Bits 0-3 of Register incremented by one, bits 4-5 unaffected.
Write $4101: Invert := Written value bit 0.
Write $4102: Input := Written value bits 0-5.
Write $4103: Mode := Written value bit 0.
Write $8000-$FFFF: Output := Register; written value is ignored.
In Mapper 136, bits 0/1 of the 8 KiB CHR ROM bank number (CHR A13/A14) come from Output bits 0/1:
8 KiB CHR-ROM bank number := (Output &3);
Games will check the lower four or six bits of $4100 for the correct value after several increment and inversion operations as a copy-protection measure.
Errata
- 麻将方块 (Mahjong Block) (TXC re-release, headerless CRC32 0ACFC3CD) is commonly set to INES Mapper 173, but since it expects Output bit 1 to select CHR A14, it actually uses INES Mapper 132. Note that the original Super Mega release of the game uses INES Mapper 172.
Similar Mappers
- Mapper 136 is almost identical to INES Mapper 132 with only 32 KiB PRG-ROM except in the value read from $4100 due to Mapper 136 having four (28-pin JV001 ASIC) versus Mapper 132 having three adder bits (24-pin 05-00002-010 ASIC).
- INES Mapper 147 expands CHR-ROM size to 128 KiB and additionally supports 128 KiB PRG-ROM, switched in 32 KiB amounts.
- INES Mapper 172 is similar to Mapper 136, connecting the six CPU bits in reverse order due to the JV001 ASIC being mounted upside down.
