Need GameBoy MBC3

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bentendo64
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Need GameBoy MBC3

Post by bentendo64 » Sun Aug 22, 2010 5:20 pm

Hi, my pokemon red version's memory bank switch bit the dust, and I would like to know of a cheap game that I can get that has MBC3 in it. I'm going to be making a memory coppier that uses the memory bank swith MBC3, but with mine broken, it's kind a hard to read/ write the memories.

that sounded really stupid, so I laugh at myself, before you can laugh at me :lol: , but I am serious.
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Snow_Cat
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Re: Need GameBoy MBC3

Post by Snow_Cat » Fri Sep 10, 2010 10:48 pm

I think Triton was thinking about doing a DIY Gameboy Flash Cart from Scrap Parts.

A quick google search shows that the MBC5 is essentially software compatible with the MBC3, except for the lack of a clock function.

ziegler.desaign.deGameBoy Cartridge Reader and Writer by Reiner Ziegler seems to have a lot of inormation about modifying cartridges.

Mostly it seems to be a problem of finding an eeprom and wiring it to the address, data and control lines.

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nitro2k01
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Re: Need GameBoy MBC3

Post by nitro2k01 » Tue Sep 14, 2010 5:16 pm

More details, please. How do you it bit the dust? How does it behave?
What is it that you want to do? Save your save data? Build a flash cartridge?
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Last edited by nitro2k01 tomorrow, 1:48 pm; edited 1 time in total

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bentendo64
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Re: Need GameBoy MBC3

Post by bentendo64 » Wed Sep 15, 2010 8:10 pm

It will use the Mega Memory card for Gameboy, made by Inter-Act. It will be able to copy memory chips (flash, eeprom, fram, etc....). You put the memory card in the gameboy, then connect the seperate board, that I made, with the MBC, a copy of a Nintendo Gameboy rom, and a breadboard. You place the memory chip into the breadboard, connect the a/d and control busses to the appropriate pins on the memory chip. Turn the Gameboy on. select "backup" on the menu. To copy to another chip, put the blank one in the breadboard, connect the wires, turn the Gameboy on, select restore, and select the file you would like to copy.

Where the MBC comes in is so I can copy up to 256k bits at a time, instead of 64k bits.
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Re: Need GameBoy MBC3

Post by nitro2k01 » Thu Sep 16, 2010 6:31 am

Still not sure I get your idea. Do you want to build a flash cartridge and use the MMC to write to the flash chip via the SRAM?
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Being the sadistic bastard I am, I have covered Frog's left eye with a Santa hat.

Last edited by nitro2k01 tomorrow, 1:48 pm; edited 1 time in total

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Re: Need GameBoy MBC3

Post by Snow_Cat » Thu Sep 16, 2010 5:30 pm

Isn't the Mega Memory cartridge was a gameboy savestate ('snapshot') copier without the ability to store games?

Now; if you are making a cartridge to hold GB/GBP/GBC games then you can use the MBC5 chip since it essentially software compatible with MBC3.
According to http://www.ziegler.desaign.de/cgbmbc5.pdf MBC5 is compatible with MBC1-5.

And here's my own analysis:
Spoiler:
information taken from: All sizes in bits, writes to ROM space is intercepted by the MBC.
common Multi-Bank Controllers:
  • none
    • (32kb max combined size)
      ROM, RAM, battery
    MBC1
    • 16Mb ROM/64kb RAM or 4M ROM/256kb RAM
      ROM, RAM, battery
      $6000-7FFF mode select w/ XXXXXXXS. S = 0 selects 16/8 mode. S = 1 selects 4/32 mode.
      $2000-3FFF ROM bank select w/ XXXBBBBB. access at 4000-7FFF. Bank 0 is always read from 0000-3FFF, setting this to 0 will infact read bank 1.
      4/32 mode:
      $4000-5FFF RAM bank select w/ XXXXXXBB, access at A000-C000.
      $0000-1FFF RAM bank enable w/ xxxx1010, else disable.
      16/8 mode:
      $4000-5FFF ROM bank select w/ XXXXXXBB, access at A000-C000.
    MBC2
    • (2Mb ROM/2kb integrated RAM)
      ROM, (RAM), Battery
      (same as MBC1 but)
      $XX00-XXFF RAM enable where XX is even. (0000-00FF spec.)
      $XX00-XXff ROM bank select where xx is odd. (2100-21FF spec.)
      $2100-21FF ROM bank select w/ XXXXBBBB, access at 4000-7FFF.
    MBC3
    • 16Mb ROM/64 kb RAM
      ROM, RAM, battery, timer
      (same as MBC1 but)
      $4000-5FFF irrelevant
      $2000-3FFF ROM bank select w/ XBBBBBBB, access at 4000-7FFF.
      (see RTC below)
    MMM01
    • besides the point
      ROM, SRAM, (battery)
    MBC5
    • 64mb ROM/ 1mb RAM
      ROM, RAM, battery, rumble
      (same as above but)
      $2000-2FFF ROM bank lower select. Bank 0 is accessible too!
      $3000-3FFF ROM bank upper select w/ XXXXXXXB, read from $4000-7fff
      $4000-5FFF RAM bank select w/ xxxxBBBB. read at A000-BFFF
      (See rumble below)
    MBC6
    • not that big an issue.
      ROM, RAM, battery, flash
    MMC3 RTC:
    • The RTC is mapped into RAM banks 8-12, and can be accessed as below:
      $0000-1fff shared RAM and RTC enable
      $4000-5FFF shared RAM and RTC select w/ XXXX10XX or xxxx11000, access at A000-C000.
      $6000-7fff latch clock data w/ 00h then 01h
      $A000+
      $0008 Seconds
      $0009 Minutes
      $000a Hours
      $000b lower days
      $000c upper days w/ xxxxxxxD.
      $000c Halt w/ xxHxxxxx. 0=active, 1=stop
      $000c Day carry w/ Cxxxxxxx. 1= counter overflow
    ALL Rumble:
    • The upper bit of the RAM address bus is linked to the motor controller, lame waste of 1/2 the address space.
Without exception MMCs 1 through 5 each contain a super set of the features of the lower levels. The specific features like SRAM, RTC and rumble have each been mapped to memory with varyign degrees of efficiency. Therfore it is preferable to substitute use the far more common MMC5 for an MMC3 chip - though that may lead to minor corruption if the user decides to set the RTC, as that would be redirected to RAM.
edit:grammar

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