Codemasters Roms, Everdrive N8 and a PAL NES.

Discuss technical or other issues relating to programming the Nintendo Entertainment System, Famicom, or compatible systems. See the NESdev wiki for more information.

Moderator: Moderators

User avatar
rainwarrior
Posts: 8734
Joined: Sun Jan 22, 2012 12:03 pm
Location: Canada
Contact:

Re: Codemasters Roms, Everdrive N8 and a PAL NES.

Post by rainwarrior »

Here's some advice on how to edit NES file header: viewtopic.php?p=188871#p188871
User avatar
TR3KT
Posts: 40
Joined: Sat Oct 01, 2016 2:20 am
Location: Australia, the land of British 50hz and obscure sports games.

Re: Codemasters Roms, Everdrive N8 and a PAL NES.

Post by TR3KT »

Sorry to bump this for anyone tied the the thread, but i've come across another weird quirk in codemasters games. When the intro plays, after the sound effect plays when 'Absolutely Brilliant!' pops up at the bottom you can hear popping and static in the background. I assumed it was my NES's PSU buzz chiming in conveniently. But it's happening in emulators as well and only during the codemasters intro after the ringing sound effect. Is it caused by some accidental writes to the APU or something?

Games i tested for:

- Micro Machines (Aladdin)
- Micro Machines (Fixed mapper)
- Micro Machines (U) (emulated)
- Ultimate Stuntman (U) (Real PAL hardware and emulator)
- Bee 52 (U) (everything)
- Cosmic Spacehead (PAL)
- And a couple of others that i have on my Everdrive but forgot the name to

You get the point. I think this weird buzzing/popping is in every codemasters game released.
User avatar
mikejmoffitt
Posts: 1353
Joined: Sun May 27, 2012 8:43 pm

Re: Codemasters Roms, Everdrive N8 and a PAL NES.

Post by mikejmoffitt »

I believe most if not all codemasters games reset the phase in vblank, so you get a buzz equal to your vertical refresh in frequency.
User avatar
Dwedit
Posts: 4924
Joined: Fri Nov 19, 2004 7:35 pm
Contact:

Re: Codemasters Roms, Everdrive N8 and a PAL NES.

Post by Dwedit »

The intro sound engine and in-game sound engines are not the same. Some of the codemasters games have the reset phase every frame issues, others do not.
Here come the fortune cookies! Here come the fortune cookies! They're wearing paper hats!
Bavi_H
Posts: 193
Joined: Sun Mar 03, 2013 1:52 am
Location: Texas, USA
Contact:

Re: Codemasters Roms, Everdrive N8 and a PAL NES.

Post by Bavi_H »

TR3KT wrote:i've come across another weird quirk in codemasters games. When the intro plays, after the sound effect plays when 'Absolutely Brilliant!' pops up at the bottom you can hear popping and static in the background. [...] Is it caused by some accidental writes to the APU or something?
FCEUX's SoundDisplay.lua shows the noise channel "pitch" and "mode" values continue changing without starting a new note, so I guess that's what's causing the faint static sound.
User avatar
TR3KT
Posts: 40
Joined: Sat Oct 01, 2016 2:20 am
Location: Australia, the land of British 50hz and obscure sports games.

Re: Codemasters Roms, Everdrive N8 and a PAL NES.

Post by TR3KT »

Interesting, i heard somewhere on this board that the awful 60hz buzz in 'Dizzy the adventurer' is caused by the same issues. Are there games developed by other companies that program the sound engine in a similar fashion cause the same static noises where silence is supposed to be?
User avatar
Dwedit
Posts: 4924
Joined: Fri Nov 19, 2004 7:35 pm
Contact:

Re: Codemasters Roms, Everdrive N8 and a PAL NES.

Post by Dwedit »

I've only seen it in Dizzy The Adventurer, and the unreleased other Dizzy game.

Homebrew rom Stars SE had a similar problem, it reset the phase every time the frequency changed, messing with vibrato effects. (Sorry Chris Covell, I know I keep pointing out bugs in this rom all the time.)
Here come the fortune cookies! Here come the fortune cookies! They're wearing paper hats!
User avatar
rainwarrior
Posts: 8734
Joined: Sun Jan 22, 2012 12:03 pm
Location: Canada
Contact:

Re: Codemasters Roms, Everdrive N8 and a PAL NES.

Post by rainwarrior »

The startup buzz is on the noise channel.

Every frame it writes $400C twice, once with volume 5, then with volume 0, 44 cycles later.

Thus, it creates a very short burst of noise (44 cycles is slightly longer than 1 sample at 44100 Hz) once per frame.

I think emulators might amplify the problem slightly due to the difficulty of filtering out this kind of high frequency effect. (Plus it really stands out against the lack of baseline noise.)
fiosbor
Posts: 1
Joined: Tue Sep 26, 2017 12:59 am

Re: Codemasters Roms, Everdrive N8 and a PAL NES.

Post by fiosbor »

rainwarrior wrote:Here's some advice Phen375 on how to edit NES file header: viewtopic.php?p=188871#p188871
not open this link viewtopic.php?p=188871#p188871

can u healp me ?
Last edited by fiosbor on Tue Oct 03, 2017 10:20 am, edited 1 time in total.
tepples
Posts: 22708
Joined: Sun Sep 19, 2004 11:12 pm
Location: NE Indiana, USA (NTSC)
Contact:

Re: Codemasters Roms, Everdrive N8 and a PAL NES.

Post by tepples »

What error message do you get when the link does "not open"?
Post Reply