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Holy Diver works on Famicom but not on NES

Posted: Wed Jun 09, 2021 11:53 am
by Danexmurder
I ran into an interesting issue with my Holy Diver cart and wanted to bring it up here. My Copy of Holy diver will not work on an NT Mini Noir, an original Analogue NT, or an NES with a Fami to NES converter. It WILL however work on a Sharp Twin Fami.

The issue I have is that the game will boot and usually let me play through the first level. If I di the game freezes after going back to the player start screen. If I beat the first boss the game will freeze after "dropping in" to the next level. I'm really curious about what could cause this.

In my attempt to get this cart working I actually replaced all of the PCB components but the Prg and Chr roms. I still have the same issue.

So... Anyone have any idea what could be causing this? Any idea on how to fix it? This one has me really stumped! If nothing else I wanted to document that there is a version of Holy Diver that exists that will only run on original Fami hardware.

Re: Holy Diver works on Famicom but not on NES

Posted: Wed Jun 09, 2021 11:56 am
by lidnariq
(Does the circuit board look at all different from the one in NesCartDB? http://bootgod.dyndns.org:7777/profile.php?id=4038 )

Re: Holy Diver works on Famicom but not on NES

Posted: Wed Jun 09, 2021 12:05 pm
by Danexmurder
I'd have to crack it back open and take a really close look but I don't think that it does. I'll do that and report back.

Re: Holy Diver works on Famicom but not on NES

Posted: Thu Jun 10, 2021 9:53 am
by Danexmurder
So I took a look at my Holy Diver PCB and the only difference that I could detect on my copy is the CHR rom is listes as IREM C-1 8907 instead of Irem C-1 8908 as it is shown on the bootgod DB page.

I did actually rip this rom using my Hardware CopyNES and even though this game won't play properly on an NES the rom works just fine in an emulator.

I also realized that there is a mistake in my first post. I hadn't tried the game out on my NT Mini Noir. Only my original Analogue NT. The game plays just fine in the Famicom slot on the NT Mini Noir.

Re: Holy Diver works on Famicom but not on NES

Posted: Thu Jun 10, 2021 1:31 pm
by krzysiobal
http://wiki.nesdev.com/w/index.php/INES_Mapper_078 wrote: Holy Diver also contains a 74HC245 to compensate for a slow CHR ROM chip.
I don't know what this exactly mean, because I did not analyz the PCB but to my best understanding - data bus goes thru that buffer, CHR-ROM is always enabled and the buffer is controlled by PPU A13 (or PPU RD?) which can go to tristate much faster than ROM and that is the benefit.

If that is the case then PRG ROM also might suffer from that, maybe this is source of problems.

Re: Holy Diver works on Famicom but not on NES

Posted: Fri Jun 11, 2021 6:14 pm
by aquasnake
Please post a picture of your cartridge.

If the Chr-rom can't cut off quickly when CE becomes high level, so use a 74xx245 to release the ppu databus, you can also try to control the OE input, because OE has shorter Tsu than CE.

crom_oe = ppu_re | ppu_ addr_ in[13];

Re: Holy Diver works on Famicom but not on NES

Posted: Sat Jun 12, 2021 8:11 pm
by Danexmurder
aquasnake wrote:
Fri Jun 11, 2021 6:14 pm
Please post a picture of your cartridge.

If the Chr-rom can't cut off quickly when CE becomes high level, so use a 74xx245 to release the ppu databus, you can also try to control the OE input, because OE has shorter Tsu than CE.

crom_oe = ppu_re | ppu_ addr_ in[13];
I’m handy with a soldering iron but code is pretty much still Greek to me. Hope this helps.

https://photos.app.goo.gl/NdZqEUA1HztZFRV37
https://photos.app.goo.gl/k64inKvKare8j8wJA
https://photos.app.goo.gl/b1Wv1bwKc6QnhYqP6

Re: Holy Diver works on Famicom but not on NES

Posted: Sat Jun 12, 2021 9:21 pm
by rainwarrior
I know there many Famicom to NES converters don't wire all the lines correctly and certain types of nametable mirroring fail to work. Wondering if the problem might be due to your converter rather than something special about the game?

Re: Holy Diver works on Famicom but not on NES

Posted: Sun Jun 13, 2021 1:16 am
by lancuster
This is what the Chinese bootleg repro looks like.
Problems when working with the Famicom didnt observe, how it works on the NES - I dont know (I cant check, I sold this cartridge).
holy diver.png