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without any diode, this cart can not sustain its sram data for one week

the last 256K page needs to be mirrored to $FE00-$FEFF 256-byte suppose hardware reset never clears the internal RAM, the next steps might be meaningful： once the loader has finished copying code to ram, then set the mapper registers to map $FFFC-$FFFF to $6FC-$6FF, and never allow to write these r...

since we can only use $200-$6FF(1.25KiB=1280Bytes) as prg-ram to copy codes here. so we need add a temporary prg rom to boot the code, which will be stored in a memory space from $FA00-FFFF. why not $FB00-$FFFF? the last 256K page needs to be mirrored to $FE00-$FEFF, which would be copied to $600-$6...

mapper71 & 232 $9xxx.bit[4]: 1-s mirroring $8xxx.bit[4:3]: outer prg address $C000-$FFFF.bit[3:0] : inner prg address cpu_addr_out[17:13] = {{outer[3], outer[4]}, inner[3:0]}; for mapper 71: cpu_addr_out[17:13] = {{cpu_addr_in[14] ? prg_bank_cdef[3:0] : inner[3:0]} , cpu_addr_in[13]} & prg_mask[17:1...

MMC5 is complicated. it can use either ciram or cxram(ext-ram mode0-1), when using the 3rd ntram， it is not simply mirroring but exactly banking ---edit--- case5 is also called as extended mirroring by wiki, it has the only ability to bank 2 nt pages(1bit) in ntram region, it can emulate the common ...

there's at least 7 morroring modes. 0. vertical 1. horizontal 2. 1-screen nt0 3. 1-screen nt1 4. 4-screen nt0-3 5. bankable 4-screen, for mapper90/mapper326, also for mapper5 if you like to 6. extra chr a17 mode, for mapper118/mapper207 for example: switch(MirrorMode) { case 0: ciram_ce = 0; cxram_c...

the powerful chinese recycling industry, especially in Shenzhen and Shantou

i purchased lots of flash chips that have not too good timing

the chr-rom of infidelity's "super mario all-stars" had better be decresed to 512K if possible, that would be easy to make a repro without an original MMC5 chip, i wish to see it one day

I don't have this cart

All my works were verified on my development board

if(prg_d_in[7:6]) prg_a_out [18:13] = prg_d_in[7:2]; else if(prg_d_in[1:0]) prg_a_out [18:13] = {prg_d_in[1:0], prg_d_in[5:2]}; else prg_a_out [18:13] = {2'b00, prg_d_in[5:2]}; maybe it is more comprehended above but i perfer prg_a_out [18:13] = {prg_d_in[7:6] | prg_d_in[1:0], prg_d_in[5:2]} on real...

[..DC BAFE] -> [FEDC BAFE] 1, ignore the lower 2 bits 2, ignore the higher 2 bits that's why iceman can only dump 128K of full 512K prg_a_out[18:13] <= {prg_d_in[7:6] | prg_d_in[1:0], prg_d_in[5:2]} on real cart, prg data bus is strongly pulled down to GND by X1-017 chip, so it is reliable: prg_d_in...

They modified the games (for example removed the RAM clearing routine) to be able to modify games behaviour, for example - change starting level, number of lives. The CHR-RAM protection was probably because they were worried that some games might write to CHR-ROM either originally or as side effect...

they pirated roms and hacked something to write to chr-ram for copy protection. first set chr-ram writes enable, then set a series of control rigisters and copy the original "chr-rom" data from nor-flash to chr-ram, last disable the chr-ram writes and quit the menu loader and jump to $FFFC to enter ...

i have reversed this cart. it works well on a pal/dendy console, but it crashes on another ntsc famiclone.

this game was developped by hummer team in taiwan in 1994. i guess this released version is for pal system only

Mapper 115 is more suitable just ignore the writes to $6000 and fetch $6001.bit[0] as mapped A18 because the standard MMC3 uses cpu_a[14:13] and cpu_a[0] to write the registers, but mapper116 needs to access $4100, which means it takes cpu_a[8]. by changing mapper116 to 115, we can save the number o...