NES 2.0 Mapper 265: Difference between revisions
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[[Category:Multicart mappers]]NES 2.0 Mapper 265 is used for T-262 multicarts, all of which use 8 KiB of CHR-RAM. It latches both address and data bits. Its UNIF board name is '''BMC-T-262'''. | [[Category:Multicart mappers|265]][[Category:Mappers with CHR RAM|265]]NES 2.0 Mapper 265 is used for T-262 multicarts, all of which use 8 KiB of CHR-RAM. It latches both address and data bits. Its UNIF board name is '''BMC-T-262'''. | ||
==Address latch== | ==Address latch== | ||
Mask: $8000 | Mask: $8000 | ||
$8000: A~[1.L. ..OO POO. .. | $8000: A~[1.L. ..OO POO. ..MN] | ||
| || ||| |+- 1=Replace PRG A14 with CPU A14 (NROM-256 when also P=1) | |||
| || ||| +-- Select nametable mirroring. 0=Vertical, 1=Horizontal | | || ||| +-- Select nametable mirroring. 0=Vertical, 1=Horizontal | ||
| ++-|++------- 128 KiB Outer PRG-ROM bank at $8000-$FFFF | | ++-|++------- 128 KiB Outer PRG-ROM bank at $8000-$FFFF | ||
| +--------- PRG-ROM banking mode | | +--------- PRG-ROM banking mode | ||
| 0: Fixed Inner PRG-ROM bank 7 at $C000-$FFFF (UNROM) | | 0: Fixed Inner PRG-ROM bank 7 at $C000-$FFFF (UNROM) | ||
| 1: Mirrored Inner PRG-ROM bank, selected by | | 1: Mirrored Inner PRG-ROM bank, selected by data latch(NROM-128) | ||
+----------------- Locking bit. 1=Prevent further writes from changing the latched | +----------------- Locking bit. 1=Prevent further writes from changing the latched | ||
address bits. The data bits, which select the inner PRG bank, | address bits. The data bits, which select the inner PRG bank, | ||
Latest revision as of 19:17, 7 July 2024
NES 2.0 Mapper 265 is used for T-262 multicarts, all of which use 8 KiB of CHR-RAM. It latches both address and data bits. Its UNIF board name is BMC-T-262.
Address latch
Mask: $8000
$8000: A~[1.L. ..OO POO. ..MN]
| || ||| |+- 1=Replace PRG A14 with CPU A14 (NROM-256 when also P=1)
| || ||| +-- Select nametable mirroring. 0=Vertical, 1=Horizontal
| ++-|++------- 128 KiB Outer PRG-ROM bank at $8000-$FFFF
| +--------- PRG-ROM banking mode
| 0: Fixed Inner PRG-ROM bank 7 at $C000-$FFFF (UNROM)
| 1: Mirrored Inner PRG-ROM bank, selected by data latch(NROM-128)
+----------------- Locking bit. 1=Prevent further writes from changing the latched
address bits. The data bits, which select the inner PRG bank,
are still changeable.
Data latch
Mask: $8000
$8000: 7654 3210
---------
.... .PPP
+++- Select 16 KiB Inner PRG-ROM bank at $8000-$BFFF,
also at $C000-$FFFF if address bit 7==1
