INES Mapper 038: Difference between revisions
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[[Category:GNROM-like mappers]][[Category:iNES Mappers]] | [[Category:GNROM-like mappers|038]][[Category:iNES Mappers|038]][[Category:in NesCartDB|038]] | ||
Mapper 38 represents another mapper | {{Infobox iNES mapper | ||
|name=iNES Mapper 038 | |||
|company=Bit Corp. | |||
|mapper=38 | |||
|nescartdbgames=1 | |||
|boards=UNL-PCI556 | |||
|prgmax=128K | |||
|prgpage=32K | |||
|chrmax=32K | |||
|chrpage=8k | |||
|mirroring=V(hardwired) | |||
|busconflicts=No | |||
}} | |||
{{nesdbbox | |||
|ines|38|iNES 038 | |||
}} | |||
[[iNES Mapper 038]] represents the board used for [[wikia:c:bootleggames:Bit Corp.|Bit Corp.]]'s [https://nescartdb.com/profile/view/4103/crime-busters Crime Busters]. It is another mapper almost identical to [[GxROM|GNROM]] ('''66''') except the bits and writeable port moved around. | |||
== Registers == | |||
=== Bank Select ($7000-$7FFF) === | |||
7 bit 0 | |||
---- ---- | |||
xxxx CCPP | |||
|||| | |||
||++- Select 32 KB PRG ROM bank for CPU $8000-$FFFF | |||
++--- Select 8 KB CHR ROM bank for PPU $0000-$1FFF | |||
Writes to $F000-$FFFF are very likely to also trigger a bankswitch, but well behaved code has no reason to. The [[74138]] used by this board uses / | == Hardware == | ||
Writes to $F000-$FFFF are very likely to also trigger a bankswitch, but well behaved code has no reason to. The [[74138]] used by this board uses /ROMSEL and R/W on its enable inputs, but /ROMSEL is 1 while M2 is low, not just while M2 is high and and A15 is low. As a result, before M2 is high, if the 2A03's A14, A13, and A12 lines are 1 and R/W is 0, the [[74161]]'s /LOAD line will still load from the data bus. | |||
Emulator oversize support | == Emulator oversize support == | ||
FCEUX (2.1.5): | FCEUX (2.1.5): | ||
$7000-$7FFF: [CCCC CCPP] | $7000-$7FFF: [CCCC CCPP] | ||
| Line 16: | Line 37: | ||
$6000-$7FFF: [CCCC CC..] | $6000-$7FFF: [CCCC CC..] | ||
[PPPP PPPP] | [PPPP PPPP] | ||
''See also:'' [[Oversize]] | |||
Latest revision as of 02:06, 14 September 2023
iNES Mapper 038
| Company | Bit Corp. |
| Games | 1 in NesCartDB |
| Boards | UNL-PCI556 |
| PRG ROM capacity | 128K |
| PRG ROM window | 32K |
| PRG RAM capacity | None |
| CHR capacity | 32K |
| CHR window | 8k |
| Nametable mirroring | V(hardwired) |
| Bus conflicts | No |
| IRQ | No |
| Audio | No |
| iNES mappers | 038 |
NESCartDB
| iNES 038 |
iNES Mapper 038 represents the board used for Bit Corp.'s Crime Busters. It is another mapper almost identical to GNROM (66) except the bits and writeable port moved around.
Registers
Bank Select ($7000-$7FFF)
7 bit 0
---- ----
xxxx CCPP
||||
||++- Select 32 KB PRG ROM bank for CPU $8000-$FFFF
++--- Select 8 KB CHR ROM bank for PPU $0000-$1FFF
Hardware
Writes to $F000-$FFFF are very likely to also trigger a bankswitch, but well behaved code has no reason to. The 74138 used by this board uses /ROMSEL and R/W on its enable inputs, but /ROMSEL is 1 while M2 is low, not just while M2 is high and and A15 is low. As a result, before M2 is high, if the 2A03's A14, A13, and A12 lines are 1 and R/W is 0, the 74161's /LOAD line will still load from the data bus.
Emulator oversize support
FCEUX (2.1.5):
$7000-$7FFF: [CCCC CCPP]
Nestopia (1.4.0h):
$6000-$7FFF: [CCCC CC..]
[PPPP PPPP]
See also: Oversize
