tepples wrote:Likewise, it's possible to have the chips ignore certain enable signals output by the mapper by playing with how the signals are routed on the PCB.
byemu wrote:The circuit of Batman and Gremlin 2 on prg is exactly the same.
byemu wrote:Batman (5a) can't bank anything to 6000~7fff (no sram on this game)
Gremlin 2(5a) can bank prg-rom to 6000~7fff (be marked as 5b in "NES Cart Database")
So you're saying that two different cartridges, both with a Sunsoft 5a, respond to writes to register 8 differently?
Is it correct to say that the Batman cartridge is entirely ignoring writes to register 8?
Does Gremlins 2 pay attention to the top two bits of register 8? (In other words, can it ever not map prg-rom in?)
name prg-size chr-size mapper can bank to 6000 bank-sram other
Barcode World 128 256 FME-7 no yes
Batman 128 128 5a no unknow
Dynamite Batman 128 256 FME-7 unknow unknow 8k-sram
Gimmick! 256 128 5b yes unknow ex-sound
Gremlins 2 128 256 5b/5a yes unknow
Hebereke 128 128 FME-7 unknow unknow
Dodge Danpei 128 256 FME-7 yes unknow
Dodge Danpei2 256 256 FME-7 unknow yes
Pyokotan no Dai Meiro 128 128 FME-7 unknow unknow
sunsoft 5a can't bank any to 6000~7fff?
sunsoft 5b can bank prg to 6000~7FFF?
sunsoft fme-7 can bank prg to 6000~7FFF and can bank sram to 6000~7fff?
update:
1 mapper 69 can bank sram or prg at 6000~7FFF,but can't bank them at the same board!
make a flash cartridge with kazzo's way, the flash /ce need connect to fme-7(5a,5b)(if you want to bank it to 6000~7fff)
2 This board has the Timing Problem,so some flash can't use here(only a few 29 series can work perfect)
lidnariq wrote:
It would be interesting to know, since you've got the sockets already, whether pseudoregister 8 still drives lines PRG ROM A13…A18 according to the latched value when it's configured to RAM. (in other words, it would be nice to know if the musing on the wiki about bankable prg-ram is true or not)
byemu wrote:
2 This board has the Timing Problem,so some flash can't use here(only a few 29 series can work perfect)
The problem could be the flash /WE pin. Original pinout has the pin connected to one of the mapper address pins and the mapper tend to drive it low, cause the flash to enter write mode and depending on what happens when the CPU crash might even corrupt what is written on the flash.
We recently tested the mapper capability for $6000 region and it could use as much as 128KB of RAM there.
byemu wrote:
2 This board has the Timing Problem,so some flash can't use here(only a few 29 series can work perfect)
The problem could be the flash /WE pin. Original pinout has the pin connected to one of the mapper address pins and the mapper tend to drive it low, cause the flash to enter write mode and depending on what happens when the CPU crash might even corrupt what is written on the flash.
We recently tested the mapper capability for $6000 region and it could use as much as 128KB of RAM there.
Thank you very much!
I found "AM29F002NT-120PC 9830MBM J @1996 AMD" on a batman cart is OK(not need a 7400).
But other Am29f002 are not ok.
and it works without problems so saying that FME7 cannot bank ROM at $6000-$7fff is not true.
BTW. I am having this cartridge for a few days so if anyone wants any special FME-7 tests then feel free to ask.
and it works without problems so saying that FME7 cannot bank ROM at $6000-$7fff is not true.
BTW. I am having this cartridge for a few days so if anyone wants any special FME-7 tests then feel free to ask.
I don't know why you saw a problem with that. The ROM and RAM have separated chip enables, both generated by the FME7 chip. When a ROM region is selected in the banking register, the RAM isn't activated by the FME-7 chip, we having the ROM activated instead. That was never thought to be a problem.