Search found 152 matches

by aquasnake
Thu Nov 26, 2020 6:11 pm
Forum: NESdev
Topic: New, homebrew mapper
Replies: 16
Views: 7349

Re: New, homebrew mapper

I'm cautious about homebrew mapper, because create a new mapper, unless you really can't find another mapper that can do the same thing. Sometimes, the existing mapper already meets the demand, and I just need to expand it a little, such as adding the address line of outer PRG bank. Sometimes it is ...
by aquasnake
Wed Nov 25, 2020 8:57 am
Forum: NES Hardware and Flash Equipment
Topic: Gryzor - interesting bootleg
Replies: 33
Views: 15879

Re: Gryzor - interesting bootleg

yes,this cart rom working 23 CRC: 295EFA08 SHA-1: 8F4202AEACC78877DD69718EE184096CC6C7F881 System: NES-NTSC Board: KONAMI VRC2/Mapper 23, Mapper 23 PRG-ROM: 128k CHR-ROM: 128k W-RAM: 8k Solder Pad: H:0 V:1 Dump: Unknown contra (ks-7049)_001.png 类似的卡带应该还有双截龙2 MAPPER 127 (但我一直没有找到这个ROM或卡带) this cart ...
by aquasnake
Tue Nov 24, 2020 10:45 pm
Forum: NESdev
Topic: FDS homebrew ?
Replies: 39
Views: 13488

Re: KYODAKU (256 bytes)

This post in November 2020 ten years later brought this old topic to mind, and I wanted to make readers who find this topic through search aware of subsequent developments as well as explore one (admittedly academic) option I had missed at the time. Nintendo were careful, and all these workarounds ...
by aquasnake
Tue Nov 24, 2020 5:40 pm
Forum: NESdev
Topic: What are ROM Nametables useful for?
Replies: 4
Views: 196

Re: What are ROM Nametables useful for?

The significance of mapping ntrom to ciram is that it can display graphics quickly without waiting to write to ciram After all, the hardware remapping is much faster than the software operation of $2006-$2007 loops. This technique is usually in junction with switching the 8K pattern of CROM to impro...
by aquasnake
Tue Nov 24, 2020 6:39 am
Forum: NES Hardware and Flash Equipment
Topic: Gryzor - interesting bootleg
Replies: 33
Views: 15879

Re: Gryzor - interesting bootleg

ks7049 is vrc2 clone, I dumped. But the mapper IC (KS204) only has 28 pins? yes,this cart rom working 23 CRC: 295EFA08 SHA-1: 8F4202AEACC78877DD69718EE184096CC6C7F881 System: NES-NTSC Board: KONAMI VRC2/Mapper 23, Mapper 23 PRG-ROM: 128k CHR-ROM: 128k W-RAM: 8k Solder Pad: H:0 V:1 Dump: Unknown con...
by aquasnake
Sun Nov 22, 2020 8:01 am
Forum: NES Hardware and Flash Equipment
Topic: Troubleshooting Top Loader Issues with power and PPU
Replies: 7
Views: 2517

Re: Troubleshooting Top Loader Issues with power and PPU

DENDY: 6527P+6538+26.601712M xtal
NTSC: 6527+6528+21.47727M xtal

make sure CPU and PPU belong to the matched chipset
by aquasnake
Fri Nov 20, 2020 6:02 pm
Forum: NESemdev
Topic: Project Nested - NES emulator for SNES
Replies: 46
Views: 25600

Re: Project Nested - NES emulator for SNES

Soon after you released this tool, some smart merchants used your works to pack NES ROM and sell them as SNES multi-carts. Some of them crashed due to imperfect emulation. I wonder if the manufacturer of this kind of cartridge has contacted you? If we are using open source products to do business, I...
by aquasnake
Fri Nov 20, 2020 6:45 am
Forum: NES Hardware and Flash Equipment
Topic: How to design the PCB of PIC18f2520 microcontroller
Replies: 9
Views: 373

Re: How to design the PCB of PIC18f2520 microcontroller

BAT54 has 0.3V Vf,it can be accepted. Some mature designs use a PMOS to control power cut-off, or LDO with EN pin. The voltage drop of the former is also 0.3V (PMOS on the power path can be seen in most designs), while the latter is more common in handheld low-power systems Diode access should be av...
by aquasnake
Thu Nov 19, 2020 5:08 pm
Forum: NES Hardware and Flash Equipment
Topic: Super Mario Bros (2 players hack) repro hell
Replies: 3
Views: 324

Re: Super Mario Bros (2 players hack) repro hell

epm240 has enough capacity to emulate VRC6

thers is one thing i dont know why VRC series (2/4 /6) are so strict with SRAM timing.
by aquasnake
Thu Nov 19, 2020 3:09 am
Forum: NES Hardware and Flash Equipment
Topic: How to design the PCB of PIC18f2520 microcontroller
Replies: 9
Views: 373

Re: How to design the PCB of PIC18f2520 microcontroller

two power sources and one destination port,should add diodes to prevent the short cut between different VDDs.

for example, when the board is powered on and connected to a download cable meanwhile
by aquasnake
Wed Nov 18, 2020 7:02 pm
Forum: NES Hardware and Flash Equipment
Topic: Why does the Game Genie only connect to PPU address lines 2, 4, 5, 6, 7, and 13?
Replies: 13
Views: 2550

Re: Why does the Game Genie only connect to PPU address lines 2, 4, 5, 6, 7, and 13?

lidnariq wrote:
Wed Nov 18, 2020 6:52 pm
aquasnake wrote:
Wed Nov 18, 2020 6:25 pm
The entire BIOS ROM has only 16K PRG ROM data.
4KB. Existing dumps are overdumps.
good news for that, i can put into menu loader
by aquasnake
Wed Nov 18, 2020 6:25 pm
Forum: NES Hardware and Flash Equipment
Topic: Why does the Game Genie only connect to PPU address lines 2, 4, 5, 6, 7, and 13?
Replies: 13
Views: 2550

Re: Why does the Game Genie only connect to PPU address lines 2, 4, 5, 6, 7, and 13?

I realized that I actually didn't have anything better to do at the moment, so I constructed a truth table for the entire ROM: A7 A6 A5 A4 A2 D0-D3 D4-D7 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0 0 0 1 1 0 1 0 0 1 0 0 0 0 0 0 1 0 1 1 0 0 0 1 1 0 0 0 0 0 1 1 1 1 1 0 1 0 0 0 0 1 0 1 0 0 1 0 0 0 1 0...
by aquasnake
Sun Nov 15, 2020 8:48 am
Forum: NES Hardware and Flash Equipment
Topic: Coolbaby RS-35 Famiclone Triangle Channel
Replies: 19
Views: 2937

Re: Coolbaby RS-35 Famiclone Triangle Channel

I'm afraid you can't change the supply voltage of noac chip. I don't mean that the input voltage of the console, whatever 9V or USB 5V. In addition, the simple way of using cement resistor plus zener diode or 8050 transistor common base circuit connection to form a drop-down voltage is a hidden dang...
by aquasnake
Sun Nov 15, 2020 3:17 am
Forum: NES Hardware and Flash Equipment
Topic: Coolbaby RS-35 Famiclone Triangle Channel
Replies: 19
Views: 2937

Re: Coolbaby RS-35 Famiclone Triangle Channel

It is not clear what causes the loss of the triangle wave channel. Since the internal triangle wave is generated by the internal operational amplifier (comparator) circuit, it is speculated that the VCC is only 3.3V, while the reference level of the comparator is internally integrated with a constan...
by aquasnake
Thu Nov 12, 2020 10:22 pm
Forum: NES Hardware and Flash Equipment
Topic: Mapper227's multi-menu display
Replies: 1
Views: 405

Re: Mapper227's multi-menu display

Using 74157 to confuse is also the cunning of pirate. If the high or low level control is realized by solder joint, it is easy to be guessed by hacker