24 pin to 32 pin SRAM

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24 pin to 32 pin SRAM
by on (#131722)
I've been trying to replace a 16kb SRAM with a 128kb SRAM and for some reason it won't work.

I've bend Pin 1-4 and Pin 25-32, since those can't be connected directly to the 24 pins.

Pin 01 - GND
Pin 02 - A16 to MaskROM
Pin 03 - A14 to MaskROM
Pin 04 - A12 to MaskROM
Pin 25 - A11 to MaskROM
Pin 26 - A09 to MaskROM
Pin 27 - A08 to MaskROM
Pin 28 - A13 to MaskROM
Pin 29 - /WE (Pin 20 SRAM) a.k.a connector #54
Pin 30 - /CE2 (MAD-1 Pin 09 (RESET)) a.k.a connector #26
Pin 31 - A15 to MaskROM
Pin 32 - +5V

Game won't save. Where would I need to connect /WE and /CE2 exactly?
/CE is connected to /OE MaskROM and /OE is connected to MAD-1 Pin 02.
I have even tested Dezeamons SRAMs pinout and it was the same. >_> Did I overlook something? Help appreciated.
Re: 24 pin to 32 pin SRAM
by on (#131724)
Does your 128k SRAM have the CE2 pin?

I'd bet your /CE (and if you have a CE2) are your problem.
Re: 24 pin to 32 pin SRAM
by on (#131725)
According to the datasheet is has CE# and CE2. It's a AS6C1008
Re: 24 pin to 32 pin SRAM
by on (#131744)
The CE2 has to be pulled high (reset line) and the /CE should connect to the mad1 or whatever the decoder is that controls the SRAM /CE line. Try that.

Side note: I'm in the process of doing the exact same thing... But I am going to use a ssop or Tsop II or a SOJ on a pcb board so it'll be a drop in replacement. But I did replace a 64k SRAM with a 1m SRAM on the 1A3M and 1J3M carts and it was pretty easy because of where Nintendo placed the Decouple caps and ground so it was only 2 legs I had to jumper I think...
Re: 24 pin to 32 pin SRAM
by on (#131784)
Whoops, I accidentaly switched WE and CE2 for some reason. I've reconnected them properly and the game saves now.

/WE was soldered to Pin 21 of the original SRAM and /CE2 was soldered to MAD-1 Pin 9 (RESET).

Thanks though. :)
Re: 24 pin to 32 pin SRAM
by on (#131786)
Double post.

The game saves and keeps the saves after a soft reset, but whenever I turn off the console and turn it back on the saves are gone. Any clue on that one? I've tested the battery and it outputs 2.7V. Even replaced it with another one, same problem.

EDIT: Nevermind the above. I made a small soldering mistake... >_<
Re: 24 pin to 32 pin SRAM
by on (#131850)
Ideally, CE2 should actually be connected to the cart's reset line.