nesdev.com

So dev cartridge is needed for testing purposes from time to time. I know that invitenes has some integration with assembler studio to debug in realtime on hardware. But i'm not sure that everdrive has something similar. So for debugging you don't have good alternatives to emulators. Topic starter h...

Nowadays for retro gamedev you can use emulator. The only reason of using dev cartridge is unique hardware.
Also everdrive clone doesn't have much difference from original, so it can be used in the same way.

Dwedit wrote: ↑

Tue May 26, 2020 5:00 pm

Two bad CPUs sounds unlikely

It is quite real situation. I have repaired famicom where both cpu are gone due to short circuit in cartridge.

But it is better to buy replacement famicom board on ebay than buy chinese cpu. It is really high chance to get faulty cpu from aliexpess.

Good job!
Seems I know one more console with the same schematics
Coolbaby RS 40
https://aliexpress.ru/item/33005168169.html

It also has problems with some cartridges and fails on chr ram test.

lidnariq wrote: ↑

Mon May 04, 2020 11:11 am

There's pedantically no "CHR RAM" on Gauntlet – it's only used for nametables.

Thank you. I also forgot about TQROM.

I've done my copies of Gauntlet and Rad Racer II for famicom. First run shown garbled graphics because I forgot that A10 and A11 of RAM should be tied to cartridge pins directly.

What does that mean? Is Forever DUO 852 Games of NES a Coolgirl cartridge, then? Because the bank register writes do not look like it. No, but it can be modified (new wiring and updating FPGA program) to use ROMs that created in Coolgirl ROM builder. FPGA is cheaper so only few mappers are availabl...

I want to understand how 4-screen mirroring implemented in DRROM board. Seemsq Gauntlet the only game that uses this approach (combine CHR RAM and ROM).
Is it correct wiring?

CIRAM /CE is tied to VCC
PA13 is tied to CHR ROM /CE
/PA13 is tied to CHR RAM /CE

This board was discussed some time ago on emu-land http://www.emu-land.net/forum/index.php ... msg1428464
Scheme was changed to work with Cluster's dumper and ROM builder. Also some mapper kits are available.

Seems latch signal doesn't match to clock signal. If you have logic analyzer, you can check signals. Or you can choose the right capacitor.

I've changed mapper register address from $4100 to $6100. You can change bytes in ROM by addresses $1e021 and $1e198 ($41 to $61) Also you need 74hc161 as latch and 74hc00 for signal inversion (you can use any other logic or transistor for this purpose). PRG RAM /CE (pin30 MMC3) -> pin12+pin13 74hc0...

It is hard to find working UA6528 on aliexpess. I also bought a couple from different stores and both were defective. So if you need ntsc chips it is better to buy famicom board in Japan.

Ice Man wrote: ↑

Mon Feb 03, 2020 12:45 pm

Would be more accurate to test in a real Famicom, not a clone console.

Always do tests on famicom, because handheld console has lower logic levels, so sometimes game works fine on it but not on famicom.
So glitches that I talk about was reproduced on famicom.

I assembled game without 74hc32 (probably it was pcb from "Terao no Dosukoi Oozumou"), and it worked but with horizontal lines in some places.
I didn't notice them at first, but then I decided to add 74hc32 and picture became clear.
Seems I have photo only after installation of hc32

NewRisingSun wrote: ↑

Mon Feb 03, 2020 10:23 am

I have removed the IRQ emulation for now, since it's not used by any game anyway, and uploaded a new build.

Now it works fine.

Mapper 115 is more suitable Do you know any donor with this mapper? 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 This game wo...