nesdev.com

its somekind of one variant of mapper52

i have 512KB PRG-RAM in my cart Okay, so you hooked the highest address bits of the PRG-ROM up to the extra address bits of the RAM? Do you have a cheap source of 512kByte SRAMs? I have a cart just like that with the same problem. due to the limitation of original mindkids' hardware, you must use a...

according to the wiki decription: $6000-7FFF: [WMCC SBPP] Multicart reg P = PRG Block (bits 1,0) = PRG A18 and A17 B = CHR+PRG Block Select bit (PRG and CHR bit 2) = CHR and PRG A19 S = PRG Block size (0=256k 1=128k) = 0=PRG A17 comes from MMC3 1=A17 comes from this register C = CHR Block (bits 1,0)...

and if your dumped size is always 512KB（2 same 512K halves), i think the mapper has locked the high address bits, unless you writes the right dumping script or removes the flash/mask rom then read by a programmer

you shall latch $8000.7 and $8001.0 before the loader execuing soft reseting procedure( PC jump to $FFFC). in another word, the mapper should always spy $8000.7 and $8001.0, once the two bits are not equal to zero, it changes the high 2 bits of outer address immediately, and never be allowed to chan...

i guess $C000 is just for latching the databus, $C001 here is to reload the counter. only $C001.bit[0] is meaningful, which selects scanline or cpu counter irq. if writing $0 to $C001, the mapper wont change the irq mode anyway, it is still scanline irq mode by default like this: 3'b100: begin // $C...

Ben Boldt wrote: ↑

Tue Jan 07, 2020 12:02 pm

aquasnake wrote: ↑

Tue Jan 07, 2020 1:47 am

i fixed the battery saving circuit, now all games do not share the very same domain of SRAM any more. each game with battery saving mode has an individal saving space

How on earth did you do that? Are you talking about a cart or emulation?

i have 512KB PRG-RAM in my cart

Thank you @NewRisingSun again, Tetris(Tengen Version) works now.

I don't understand your reply. Does your mapper hardware implementation respond to writes in both the $5xxx and $6000-$7FFF range, or only to writes in the $5xxx range? i mean i can play other games except #129, i dont konow which this mapper is. yes!!! you probably pointed out the reason, my code ...

You mean, how was the game changed to work as MMC3? Not at all, it uses the mapper's "GNROM mode". The game's original CHR-ROM switch at $A7EB has been changed from "STA FFF6,X" (CNROM-latch) to "STA 5002" ("CHR offset for GNROM mode"). However, the game also has a number of garbage writes in the $...

Game #129, titled "TETRIS1", is Tengen's Tetris (mapper 3/148), not Nintendo's Tetris. At least in the ROM image that I have, PRG-ROM CRC32 4026EED1. thanks for providing this information，and how could mapper268 change into mapper3 mode? maybe it is still mapper4, through hacking mapper3 to mapper4

i fixed the battery saving circuit, now all games do not share the very same domain of SRAM any more. each game with battery saving mode has an individal saving space

i have no idea whether mapper 268 could support MMC1, because the official "Tetris (U) [!].nes" is MMC1, its beyond the wiki description

I cloned the total hardware and its mapper formation with my own physical hardware, so here is the running pic

i've almost done this reverse engineering from some modern multi-carts. now pocketgames 150-in-1 works well. except one game of super game 143-in-1 from mindkids, which is number 129: TETRIS1. i can't enter this game from the menu, it shows a black screen. does anyone have time to help test this pro...