SNES SA-1 Multicart Question

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hidden0
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SNES SA-1 Multicart Question

Post by hidden0 »

Hello,

I just finished upgrading Sram and making a Gradius III SA-1 Hack Cartridge,
I was thinking to make a multi cart my question is do we need to double the Sram if i plan to use 2 games which require 256kbit each , Like we do in Normal Cartridges.

Image

Since upgrading and manual wiring experiment on 1L3B boards were hard to do.
Limewater
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Re: SNES SA-1 Multicart Question

Post by Limewater »

hidden0 wrote:Hello,

I just finished upgrading Sram and making a Gradius III SA-1 Hack Cartridge,
I was thinking to make a multi cart my question is do we need to double the Sram if i plan to use 2 games which require 256kbit each , Like we do in Normal Cartridges.

Image

Since upgrading and manual wiring experiment on 1L3B boards were hard to do.


You should not need to double the SRAM. If each of the two games require 256kbit, you should just need 256kbit.

You need to double ROM because both games have to reside in ROM at all times.

Only one game at a time uses the SRAM, so you don't need to double it.
Systems: TI-99/4a, Commodore Vic-20, Atari 2600, NES, SMS, GB, Neo Geo MVS (Big Red 4-slot), Genesis, SNES, 3DO, PS1, N64, DC, PS2, GBA, GCN, NDSi, Wii
hidden0
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Re: SNES SA-1 Multicart Question

Post by hidden0 »

Limewater wrote:
hidden0 wrote:Hello,

I just finished upgrading Sram and making a Gradius III SA-1 Hack Cartridge,
I was thinking to make a multi cart my question is do we need to double the Sram if i plan to use 2 games which require 256kbit each , Like we do in Normal Cartridges.

Image

Since upgrading and manual wiring experiment on 1L3B boards were hard to do.


You should not need to double the SRAM. If each of the two games require 256kbit, you should just need 256kbit.

You need to double ROM because both games have to reside in ROM at all times.

Only one game at a time uses the SRAM, so you don't need to double it.


We do need Double the SRAM it when we make normal multi Cartridge. Why not in this one ?
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Ziggy
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Re: SNES SA-1 Multicart Question

Post by Ziggy »

If the game uses SRAM as work RAM, then no, you would not need to double it. If both ROMs use SRAM as save RAM, then yes, you would need to double it (or else each game would overwrite the other's save).
hidden0
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Re: SNES SA-1 Multicart Question

Post by hidden0 »

Ziggy587 wrote:If the game uses SRAM as work RAM, then no, you would not need to double it. If both ROMs use SRAM as save RAM, then yes, you would need to double it (or else each game would overwrite the other's save).


Yea that make sense the games i wanna use they don't even save they might use Sram as SA-1 Work Ram i believe.
Limewater
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Re: SNES SA-1 Multicart Question

Post by Limewater »

Yeah, since Gradius III doesn't have a save battery, I assumed the SRAM was just work ram.

I'm confused, though, because the PCB you are using has a battery. I didn't register that before.
Systems: TI-99/4a, Commodore Vic-20, Atari 2600, NES, SMS, GB, Neo Geo MVS (Big Red 4-slot), Genesis, SNES, 3DO, PS1, N64, DC, PS2, GBA, GCN, NDSi, Wii
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Ziggy
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Re: SNES SA-1 Multicart Question

Post by Ziggy »

The PCB has a battery because it is a donor cart and whatever game it was originally had save RAM. But whatever game(s) he's trying to make will not necessarily need the battery (in which case I would remove it).
hidden0
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Re: SNES SA-1 Multicart Question

Post by hidden0 »

Ziggy587 wrote:The PCB has a battery because it is a donor cart and whatever game it was originally had save RAM. But whatever game(s) he's trying to make will not necessarily need the battery (in which case I would remove it).


Thats good thanks, One more question

according to this

Code: Select all

http://romlaboratory.dbwbp.com/romlab/hirom.htm


Cartridge Pin 26 is the RESET , on a normal cartridge but with Special Chip Cartridge i can't find the /RESET Pin since it has more Connector's at the bottom , I am planning to use 74hc74 flipflop or CD4040 chip for Reset type multi cartridge.

http://romlaboratory.dbwbp.com/romlab/snesconn.gif
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Ziggy
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Re: SNES SA-1 Multicart Question

Post by Ziggy »

It's still Pin 26, even on carts with the extra pins. They're labeled on the PCB, so it's easy to find.

Image
hidden0
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Re: SNES SA-1 Multicart Question

Post by hidden0 »

Ziggy587 wrote:It's still Pin 26, even on carts with the extra pins. They're labeled on the PCB, so it's easy to find.

Image


Thats alot man , Will def update , Trying to make

Contra + Race Drivin + SMW + Super R-Type (SA1 HACKS) Multicart.
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