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PostPosted: Sat Apr 11, 2015 6:01 pm 
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I have to ask this again. MMC5 is complicated and there are little to no carts to test the game on.
While I'm brainstorming about a game until I have time to make it, I like to know exactly what I can and can't do.
The game I wanted to make in the first place seemed like a divergent thinking and now I have to do something convergently.
I need a mapper & existing cartridge configuration close with these capabilities:
  • 1KB CHR-ROM bank address spaces for sprites
  • Battery powered RAM for saving the game
  • At least 2 PRG-ROM bank address spaces
  • 4 screens for scrolling


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PostPosted: Sat Apr 11, 2015 6:14 pm 
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Have you seen my summary of almost-all mappers on the wiki? nesdevwiki:User:Lidnariq/MMC3 Variants.

4-screen layout will require adding extra RAM to the cartridge. Otherwise, almost no cartridges have it: one each MMC3 and Namco 108 cartridges, and Napoleon Senki.


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PostPosted: Sat Apr 11, 2015 6:32 pm 
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Alright, how about no 4 screen, but horizontal scrolling?


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PostPosted: Sat Apr 11, 2015 6:49 pm 
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Basically anything that provides non-trivial banking control will provide horizontal layout=vertical mirroring. At absolute worst, you could always cut the relevant traces and fix it to horizontal layout.

But go to my wiki page and click on "PRG bank style" to separate it into ones that provide more than one adjustable bank, and click on "CHR bank style" to separate it into ones that support 1 KiB banks.


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PostPosted: Sat Apr 11, 2015 7:17 pm 
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You don't need 4 screens to scroll in all directions. A lot of games do it with a single name table even (with a few glitches at the edges though). With a few tricks you can achieve 100% glitch-free multidirectional scrolling using only the 2 stock name tables. This is even easier if you have scanline IRQs at your disposal.


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PostPosted: Sat Apr 11, 2015 9:13 pm 
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A customized FME-7 board, essentially the Batman: Return of the Joker board with a battery and a few passives soldered onto it, should meet all requirements other than the 4-screen mirroring.


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PostPosted: Sun Apr 12, 2015 12:34 pm 
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Found VRC4, VRC7 and Sunsoft FME-7. They have interrupts on scanlines.
tepples wrote:
A customized FME-7 board, essentially the Batman: Return of the Joker board with a battery and a few passives soldered onto it, should meet all requirements other than the 4-screen mirroring.

I think I'll go for that. How would the iNES header in NESASM6 look like?


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PostPosted: Sun Apr 12, 2015 12:45 pm 
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The MMC3 might be a better choice, since it's more common, depending on what you need.

It can only bank half the CHR at 1k, and the other half is 2k banks. (4 x 1k + 2 x 2k).


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PostPosted: Sun Apr 12, 2015 12:52 pm 
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8bitMicroGuy wrote:
Found VRC4, VRC7 and Sunsoft FME-7. They have interrupts on scanlines.
That's a weird subset...

If you're specifically looking for eight 1 KiB CHR banks and any kind of IRQ, I'd have thought that RAMBO-1, Namco 163/175/340, Jaleco SS88006, and Irem H3001would also satisfy, VRC6, possibly, if the PRG banking isn't too weird.


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PostPosted: Sun Apr 12, 2015 1:49 pm 
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So which games have:
  • Either VRC4, VRC7 or Sunsoft FME-7 mapper
  • Battery powered RAM for saving the game
  • At least 128kB PRG and 64kB CHR
  • Horizontal scrolling
  • Desolderable ROM chips so I can replace them with Flash or EEPROM chips
  • IRQ connected on the PCB for scanlines


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PostPosted: Sun Apr 12, 2015 2:24 pm 
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rainwarrior wrote:
The MMC3 might be a better choice, since it's more common, depending on what you need.

FME-7 is as common as you need it to be. (Source: Infinite NES Lives: NES Supplies)

Quote:
So which games have

Have Paul at infiniteneslives.com hook you up with a battery-backed FME-7 board for $17.50. Solder some sockets on, drop in flash memories up to 2 Mbit each (256K + 256K), and go.


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PostPosted: Sun Apr 12, 2015 3:09 pm 
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8bitMicroGuy wrote:
Horizontal scrolling

Why is this relevant? The FME-7 has configurable name table mirroring, so you can scroll any way you want.

Multidirectional scrolling, like in any other cart without extra name RAM, regardless of the mapper, requires a couple o tricks to be 100% glitch-free.


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PostPosted: Mon Apr 13, 2015 3:00 pm 
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FME7 does irq on cpu cycles, not scanlines.


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PostPosted: Mon Apr 13, 2015 3:26 pm 
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Let me get it straight.
"FME-7 Just add EPROM board" is the board that I insert into an NES console to play when I'm finished with assembly and upload. On that board, I solder sockets and put in "Flash memory sizes FME-7/Sunsoft-5". Then I insert that board into "Kazzo cartridge "INL Retro" Dumper-Programmer" and program the flash chips.

Now, as I'm unable to get these at the moment, what kind of iNES header in NESASM6 do I need for this configuration?:
  • FME-7 w/battery backed WRAM
  • PRG-ROM: 256KB
  • CHR-ROM: 256KB

I want to start programming that Mario-like game and I need this configuration to be correct.


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PostPosted: Mon Apr 13, 2015 3:28 pm 
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tepples wrote:
rainwarrior wrote:
The MMC3 might be a better choice, since it's more common, depending on what you need.

FME-7 is as common as you need it to be. (Source: Infinite NES Lives: NES Supplies)


I'd estimate there are at least 100 times as many MMC3 chips in the world as FME-7. It might even be as much as 1000 times.

Yes, INL will make a clone of FME-7, or also MMC3, or he's capable of building new custom mappers too, really.


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