Cart DB #70: City Fighter 4

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
U1	AX5208C(VRC4)
U2	16V8
U3	27F080
U4	27F080
C1	?
C2	-
C3	-
C4	-
C5	-
C6	-
C7	-
CART1	FAMICOM_CART
R1	510R
R2	1k
R3	2k
R4	3,9k
R5	1k
R6	10k

Name

Value

AX5208C(VRC4)

16V8

27F080

CART1

FAMICOM_CART

510R

3,9k

10k

The whole story started when trying to make repro of City Fighter 4 ([url=http://wiki.nesdev.com/w/index.php/NES_2.0_Mapper_266]mapper 266[/url]) [img]https://obrazki.elektroda.pl/2514959500_1608423589.png[/img] [img]https://obrazki.elektroda.pl/8600890500_1608423591.png[/img] Thanks to wiki, I was able to get how the registers works. It does not say however how the DAC is realized so I made a resistor ladder: [url=https://obrazki.elektroda.pl/2766966600_1608423764.jpg][img]https://obrazki.elektroda.pl/2766966600_1608423764_thumb.jpg[/img][/url] [url=https://obrazki.elektroda.pl/4179655900_1608423765.png][img]https://obrazki.elektroda.pl/4179655900_1608423765_thumb.jpg[/img][/url] [url=https://obrazki.elektroda.pl/1037734100_1608423771.png][img]https://obrazki.elektroda.pl/1037734100_1608423771_thumb.jpg[/img][/url] https://www.youtube.com/watch?v=Dcj0r5pjIVc Then, somebody shown me how the original PCB looks like so I made a schematic: [url=https://obrazki.elektroda.pl/4363537200_1608423852_org.jpg][img]https://obrazki.elektroda.pl/4363537200_1608423852_thumb.jpg[/img][/url] [url=https://obrazki.elektroda.pl/5192091600_1608423854_org.jpg][img]https://obrazki.elektroda.pl/5192091600_1608423854_thumb.jpg[/img][/url] [url=https://obrazki.elektroda.pl/1460149800_1608423862_org.jpg][img]https://obrazki.elektroda.pl/1460149800_1608423862_thumb.jpg[/img][/url] [url=https://obrazki.elektroda.pl/5117277600_1608423880.png][img]https://obrazki.elektroda.pl/5117277600_1608423880_thumb.jpg[/img][/url] [url=https://obrazki.elektroda.pl/2854090000_1608424999_org.jpg][img]https://obrazki.elektroda.pl/2854090000_1608424999_thumb.jpg[/img][/url] There are some interesting facts: * PRG ROM D3 and D5 are reversed (copy protection?) * The resistor ladder is different than mine. * Wiki says about using pin /WR900C of VRC4 to decode $900C/$980C, which sounds logical, because together with VRC4's OR gate and CPU-A11 it would work indeed: [code] CPU-A11 - |VRC4 OR A VRC4 OR Y | - WR9800C +- |VRC4 OR B | | | | | | /WR900C| -+ | | +------------------------------+ [/code] but instead, PAL is used to perform the decoding and latch six bits (four for AUDIO DAC and two for PRG data) * Despite using 32kB PRG banks (which would suggest that VRC4 is not involved in PRG banking at all), VRC4 drives PRG-A13 and PRG-A14. To make 32KB banks works as expected: [code] $8000 $a000 $c000 $e000 0 1 2 3 [/code] game should initialize: * PRG REG0 at $8000 to 0 * PRG REG1 at $a000 to 1 (which is accessed at $c000 because of mixed CPU-A13 and CPU-A14) and it does it! [code] 01:FE96: A9 00 LDA #$00 01:FE98: 8D 98 93 STA $9398 01:FE9B: 8D A0 86 STA $86A0 ! ... 01:FE9E: A9 01 LDA #$01 01:FEA0: 8D 30 CD STA $CD30 ! [/code] NewRisingSun - you made the wiki description of Mapper 266. Do you have different revision of this cartridge?

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#
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