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Last updated on Oct-18-2019 Download

VS Duck Hunt NES-hack

VS Duck Hunt NES-hack
by on (#126094)
A few of you might have tried my VS Duck Hunt -> NES hack. However I've just discovered something odd.
It works fine in emulators but there seems to be graphical glitches on hardware (=Power Pak). See attached movie.
When studying the movie you can see that the graphics glitches always appear on certain frames in character animation. I'm beginning to think
there's something bad about the CHR-ROM. But as previously mentioned, in works on emulators. Which makes me wonder, is there something
PowerPak is doing that the emulators are not?

EDIT: "play quicktime movie" button below works bad for me in FF, download the file instead (it's just 1.6MB).
Re: VS Duck Hunt NES-hack
by on (#126176)
Test it on a real NROM cart, because powerpaks without those fixing resistors on the PPU lines will have glitches on some systems.
Re: VS Duck Hunt NES-hack
by on (#126184)
No other games I've tried show such symtoms..
Re: VS Duck Hunt NES-hack
by on (#126186)
There are many details about the NES that are not commonly emulated, so they will show up on hardware tests but nowhere else.

Could you describe your hack? Especially what does the NMI routine look like?
Re: VS Duck Hunt NES-hack
by on (#135589)
My PowerPak has the resistor mod and I see more or less the same sprite glitches as shown in the video on my real NES.

Also, Hogan's Alley VS with your patch will not register light gun input on my PowerPak and real NES, so I am stuck at the Player 1-2 select screen.
Re: VS Duck Hunt NES-hack
by on (#135737)
I remember some guy had put my VS Duck Hunt patch on a cartridge and mentioned no problems with graphic-glitches so I wonder if this is a Powerpak-issue. Wonder how it looks on the NES Everdrive..

Yeah Hogans Alley is broken sorry to say. They used 4-screen mirroring for some reason and that caused me alot of headaches (along with *BADLY* coded emulators that relied on CRC's for proper emulation of VS-functionality that made debugging close to impossible).
Re: VS Duck Hunt NES-hack
by on (#135738)
3gengames wrote:
Test it on a real NROM cart, because powerpaks without those fixing resistors on the PPU lines will have glitches on some systems.

PowerPak has for a long time now included the resistors by default, so unless the PowerPak op is using is from the very first batch (from 2007 or so, I think), that shouldn't be the problem.