74LS139 Logic inside SNES Cartridges

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Ice Man
Posts: 546
Joined: Fri Jul 04, 2014 2:34 pm

74LS139 Logic inside SNES Cartridges

Post by Ice Man » Fri Aug 07, 2015 6:29 am

I've already succeed in resoldering the onboard 74LS139 Decoder found in SHVC-1AXB-XX boards to support 27c322 (32MBit) games and save properly.

Connections here:
Pin 01 = SNES Cart 49 /OE
Pin 02 = SNES Cart 40
Pin 03 = SNES Cart 40
Pin 04 = Pin 15
Pin 05 = NC
Pin 06 = NC
Pin 07 = ROM /OE
Pin 08 = GND
Pin 09 = RAM /CE
Pin 10 = NC
Pin 11 = NC
Pin 12 = NC
Pin 13 = A21
Pin 14 = A20
Pin 15 = Pin 04
Pin 16 = VCC

However, I'd like to know how this will work for HiROM games?
There's only one afaik: Final Fantay V that uses SHVC-1J3B-XX board.
Does anyone have the 74LS139 pinout for that cartridge?
Help appreciated.

MaxTheWhale
Posts: 1
Joined: Sun Aug 09, 2015 2:04 pm

Re: 74LS139 Logic inside SNES Cartridges

Post by MaxTheWhale » Sun Aug 09, 2015 2:24 pm

Here is the 139 pinout from my 1J3B-01 cart:

Pin 01 - SNES Cart 40 (A15)
Pin 02 - SNES Cart 38 (A13)
Pin 03 - SNES Cart 39 (A14)
Pin 04 - NC
Pin 05 - NC
Pin 06 - NC
Pin 07 - Pin 15
Pin 08 - GND
Pin 09 - NC
Pin 10 - NC
Pin 11 - RAM /CE
Pin 12 - NC
Pin 13 - SNES Cart 47 (A22)
Pin 14 - SNES Cart 46 (A21)
Pin 15 - Pin 7
Pin 16 - VCC

Ice Man
Posts: 546
Joined: Fri Jul 04, 2014 2:34 pm

Re: 74LS139 Logic inside SNES Cartridges

Post by Ice Man » Wed Aug 12, 2015 12:39 pm

Thanks alot, that will help me.

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poorstudenthobbyist
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Re: 74LS139 Logic inside SNES Cartridges

Post by poorstudenthobbyist » Sun Mar 07, 2021 10:49 am

Sorry for the necro-bump, but for posterity's sake - someone was asking me about this pinout and I found my 1A3B's '139 to be wired a bit differently.

Pin 1 (/1E): Cart 49 (/ROMSEL or /CART)
Pin 2 (1A): Cart 46 (BA5)
Pin 3 (1B): Cart 47 (BA6)
Pin 4 (1Y0): ROM /OE
Pin 7 (1Y3): '139 pin 15 (/2E)
Pin 8 (VSS): GND
Pin 9 (2Y3): SRAM /CE
Pin 13 (2B): Cart 26 (/RESET)
Pin 14 (2A): Cart 45 (BA4)
Pin 15 (/2E): '139 pin 7 (1Y3)
Pin 16 (VCC): VCC
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Fisher
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Re: 74LS139 Logic inside SNES Cartridges

Post by Fisher » Mon Mar 08, 2021 4:04 pm

poorstudenthobbyist wrote:
Sun Mar 07, 2021 10:49 am
Sorry for the necro-bump, but for posterity's sake - someone was asking me about this pinout and I found my 1A3B's '139 to be wired a bit differently.
Interesting.
I've got a pirate Super Mario All Stars + Super Mario World that's wired almost like yours, but is a little different since it uses 2 epoxy blobs as ROMs:

Pin 1 (/1E): Cart 49 (/ROMSEL or /CART)
Pin 2 (1A): Cart 47 (BA6)
Pin 3 (1B): GND
Pin 4 (1Y0): ROM0 /OE
Pin 5 (1Y1): '139 pin 15 (/2E)
Pin 6 (1Y2): NC
Pin 7 (1Y3): NC
Pin 8 (VSS): GND
Pin 9 (2Y3): SRAM /CE
Pin 10 (2Y2): NC
Pin 11 (2Y1): NC
Pin 12(2Y0): ROM1 /OE
Pin 13 (2B): Cart 46 (BA5)
Pin 14 (2A): Cart 45 (BA4)
Pin 15 (/2E): '139 pin 5 (1Y1)
Pin 16 (VCC): VCC

I also noticed that the battery circuit of my pirate card probably is not functional.
It's missing a resistor that I think should pull the SRAM /CE up and the transistor with it's respective resistor.
I'll take a look at your site and do the alterations to make it the same as yours, if you don't mind.

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poorstudenthobbyist
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Re: 74LS139 Logic inside SNES Cartridges

Post by poorstudenthobbyist » Mon Mar 08, 2021 5:04 pm

So a note about the 1A3B wiring, this means with this board making games larger than 14 Mbit with any amount of SRAM is not possible, because pin 40 does not connect anywhere (unless someone else more clever than me can come up with a method)
Fisher wrote:
Mon Mar 08, 2021 4:04 pm
I also noticed that the battery circuit of my pirate card probably is not functional.
It's missing a resistor that I think should pull the SRAM /CE up and the transistor with it's respective resistor.
I'll take a look at your site and do the alterations to make it the same as yours, if you don't mind.
That's what it's there for!
Check out my website for NES, SNES, and Genesis tutorials here. And visit my store for some custom tools and boards for making games here.

You can also follow me on Twitter for infrequent updates and bad jokes!

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