Cart DB #295: NES-21G-CPU-72P

Notes for chip search:

Use "+" as delimeter for all fields (except "cart name", where space is used); if many values are entered, all of them must appear in the cartridge then; case is not sensitive
"Mapper" is the actual mapper used by this cartridge hardware (might not match the one at wiki.nesdev.com, as at the moment I was analyzing this cartridge, there was no mapper assigned to it, so I had to assign my own number for testing)
"Original mapper" is the mapper used by licensed version of this game (for multicarts, it refers to mapper of the inside games, so 0+2 means this cartridge can run NROM+UNROM games)
Order in which you put values doesn't matter (you can write 7400+74138+7400 or 7400+7400+74138 to search for a cartridge that contains at least two 7400 chips and one 74138
Some chips (like PAL16*8) appear in cartridges as 16V8 or 16L8, so be sure to check both posibilities
Same goes for memories - type 27F080 to search for 32 pin memories, 27512 for 28 pin with two chip enables or MASKROM_1M_DIP28 for 28 pin with one chip enable
Same goes for mappers - some examples: AX5904(MMC1), AX5202P(MMC3), PT8154BM (9112MMC3), AX5208C(VRC4), 23C3662(VRC2)
Good news is that you can use wildcards, so 74139+*MMC3* will search for any cartrige that has at least one 74139 and MMC3 chip in any version

Name	Value
IC1	CIC (3193A)(DIL16)
IC2	7404 (-)(7404)
IC3	7432 (-)(7432)
IC4	74138 (-)(74138)
IC5	NEC 64S20(6264)
IC6	74374 (-)(74374)
IC7	27512
C1	-
C10	?
C11	-
C12	?
C2	-
C3	-
C4	-
C5	-
C6	-
C7	-
C8	?
C9	51p (-)
CON1	NES_CART
D1	-
D2	-
D3	-
D4	-
JP1
JP2
JP3	JUMPER-CUT
R1	510k (-)
R2	510k (-)
R3	3.3k (-)
RX	1k (-)
TR1	-

Name

Value

IC1

IC2

IC3

IC4

IC5

IC6

IC7

C10

C11

C12

51p (-)

CON1

NES_CART

JP1

JP2

JP3

JUMPER-CUT

510k (-)

3.3k (-)

1k (-)

TR1

Hey, I think there is not much to guess: 74374 latches on writes at $6000-$67FF. latched $6000.0 is driven to EXP0 latched $6000.1 is driven to EXP1 latched $6000.2 is driven to EXP2 latched $6000.3 is driven to EXP3 latched $6000.4 is driven to EXP4 latched $6000.5 is driven to EXP9 latched $6000.6 is driven to EXP8 latched $6000.7 drives T1: when 1, TR1 pulls down /IRQ to GND and also is output to EXP7 (EXP7 = M2 or $6000.7) EXP6 is 0 when reading $6000-$67ff and 1 otherwise EXP5 drives PRG /OE PRG /CE was meant to be driven by /ROMSEL but I see a big blob of solder shorting it to GND (I am not sure, but the track near edge connector pin 50 = /ROMSEL is completely removed?) Maybe the goal was to disable the PRG on some occasions via EXP5 (just like I did with the opcode inction that disables PRG-ROM for a few cpu cycles and the injects its own data to the CPU?)

Cart name		Notes for chip search: Use "+" as delimeter for all fields (except "cart name", where space is used); if many values are entered, all of them must appear in the cartridge then; case is not sensitive "Mapper" is the actual mapper used by this cartridge hardware (might not match the one at wiki.nesdev.com, as at the moment I was analyzing this cartridge, there was no mapper assigned to it, so I had to assign my own number for testing) "Original mapper" is the mapper used by licensed version of this game (for multicarts, it refers to mapper of the inside games, so 0+2 means this cartridge can run NROM+UNROM games) Order in which you put values doesn't matter (you can write 7400+74138+7400 or 7400+7400+74138 to search for a cartridge that contains at least two 7400 chips and one 74138 Some chips (like PAL168) appear in cartridges as 16V8 or 16L8, so be sure to check both posibilities Same goes for memories - type 27F080 to search for 32 pin memories, 27512 for 28 pin with two chip enables or MASKROM_1M_DIP28 for 28 pin with one chip enable Same goes for mappers - some examples: AX5904(MMC1), AX5202P(MMC3), PT8154BM (9112MMC3), AX5208C(VRC4), 23C3662(VRC2) Good news is that you can use wildcards, so 74139+MMC3* will search for any cartrige that has at least one 74139 and MMC3 chip in any version
Mapper#
Original mapper#
PCB marks
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