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View topic - Rewritable SMS cartridge--has anyone successfully done so?

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MrVCD
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Rewritable SMS cartridge--has anyone successfully done so?
Post Posted: Sat Feb 05, 2000 6:44 pm
Hi,


I am interested in knowing if anyone has made some sort of rewriteable SMS cartridge. I am a purist meaning i like to play my games on the real hardware, rather than an emulator.

If anyone has made or knows where to get a rewriteable SMS cartridge, please email me

[email protected]

Thanx
 
  • Joined: 24 Jun 1999
  • Posts: 1732
  • Location: Paris, France
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Post Posted: Sat Feb 05, 2000 9:40 pm
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> I am interested in knowing if anyone has made some sort of rewriteable SMS cartridge. I am a purist meaning i like to play my games on the real hardware, rather than an emulator.

No one has done it at my knowledge - yet.

Quote
> If anyone has made or knows where to get a rewriteable SMS cartridge, please email me
> [email protected]

This kind of discussion can stay here I believe :)
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  • Joined: 12 Jul 1999
  • Posts: 871
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Didn't we have a big long discussion about this once apon a time? *nt*
Post Posted: Sun Feb 06, 2000 3:12 am
Quote
> > I am interested in knowing if anyone has made some sort of rewriteable SMS cartridge. I am a purist meaning i like to play my games on the real hardware, rather than an emulator.

> No one has done it at my knowledge - yet.

> > If anyone has made or knows where to get a rewriteable SMS cartridge, please email me
> > [email protected]

> This kind of discussion can stay here I believe :)
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Nyef
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At least thrice. I _think_ I know how to build one but it requires sacrificing a real cart, and can't page. *nt*
Post Posted: Sun Feb 06, 2000 5:51 am
No, seriously, there's no text here.
 
  • Joined: 24 Jun 1999
  • Posts: 1732
  • Location: Paris, France
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Then .. (text)
Post Posted: Sun Feb 06, 2000 8:44 am
Tell us how to. At least describe your ideas.
I've got hundred of carts to sacrifiate :)
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Nyef
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Re: Then .. (text)
Post Posted: Mon Feb 07, 2000 2:08 pm
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> Tell us how to. At least describe your ideas.
> I've got hundred of carts to sacrifiate :)

Okay, here goes:

1.: Desolder the ROM chip.
2.: Figure out the complete ROM pinout.
3.: Add a protoboard to the cart PCB by running wire through the holes for the ROM chip on the PCB and holes on the protoboard, soldering to both boards.
4.: Higher up on the protoboard, add a socket for an EPROM or EEPROM (suggest FlashROM, but that's just because I can still get my paws on some).
5.: Referring to the pinout of step 2, add wires from where you joined the boards in step 3 to the socket of step 4.

Problems: No bankswitching. You're limited to at most 48k of ROM (and that's if you're lucky, it may need extra parts). Will not fit in a standard cart case.

Further ideas: (some of these might be easier if you add another protoboard)

Bankswitching. If you're willing to break compatability, this should be a matter of adding about 3 chips of discrete logic. If you want the full SMS switch, you will probably want to use a PAL or something.
Backup RAM. Should not be too hard if you've gone the PAL route for bankswitching. For even more fun, you should be able to use any cart dumper that attaches via card-edge connector to upload and download the contents of the RAM.
In-system programming. If you're using FlashROM and have some form of bankswitching, you should be able to reprogram the game while it's in the system. Combine with a GG and converter, and you have a portable self-hosting devkit. Add a switch tied to an XOR gate on one of the address lines for separate development and test modes.

--Nyef
 
Nyef
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The thought occurs...
Post Posted: Tue Feb 08, 2000 6:34 pm
... That one could use a chunk of ribbon cable with DIP headers on each end to run the cart signals out to a solderless breadboard. There may be power issues with this, but you wouldn't run out of space for chips as easily.

-- Nyef
 
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