Discuss hardware-related topics, such as development cartridges, CopyNES, PowerPak, EPROMs, or whatever.
Moderators: B00daW, Moderators
-
yxkalle
- Posts: 62
- Joined: Sun Jan 27, 2013 7:30 pm
Post
by yxkalle » Thu Sep 26, 2013 4:18 pm
Can I use an YMZ284 instead if I connect:
PRG A13 to A0
(NOT PRG_CE) NAND PRG_A14 to /CE (/CE goes low when PRG /CE is low AND PRG A14 is high)
PRG R/W to /WR
...and everything else like the previous versions? I'm new to this cart hacking stuff.
Thanks
-
Jarhmander
- Formerly ~J-@D!~
- Posts: 516
- Joined: Sun Mar 12, 2006 12:36 am
- Location: Rive nord de Montréal
Post
by Jarhmander » Thu Sep 26, 2013 5:57 pm
Yes, I did exactly that and it works. Interestingly, R/W doesn't really work on this chip and it is not possible to read it, so there will never be bus conflicts with reads with this chip.
Beware: the output is quite weak and is only able to source current; it can't sink current.
((λ (x) (x x)) (λ (x) (x x)))
-
yxkalle
- Posts: 62
- Joined: Sun Jan 27, 2013 7:30 pm
Post
by yxkalle » Thu Sep 26, 2013 6:13 pm
Thank you very much! Maybe I can use one of the NAND-gates (74HC02) to form a NOT-gate and use a feedback resistor to use it as a crude amplifier to save a chip? Nintendo used that trick to amplify the sound output of the 2A03. Probably I should just use an op-amp, but I like "elegant" solutions.

-
l_oliveira
- Posts: 407
- Joined: Wed Jul 13, 2011 6:51 am
- Location: Brasilia, Brazil
Post
by l_oliveira » Thu Sep 26, 2013 6:34 pm
yxkalle wrote:Thank you very much! Maybe I can use one of the NAND-gates (74HC02) to form a NOT-gate and use a feedback resistor to use it as a crude amplifier to save a chip? Nintendo used that trick to amplify the sound output of the 2A03. Probably I should just use an op-amp, but I like "elegant" solutions.

That's how the ORIGINAL game works so I don't see why that wouldn't work.
Edit: I think it has to be HCU type though ...
-
yxkalle
- Posts: 62
- Joined: Sun Jan 27, 2013 7:30 pm
Post
by yxkalle » Thu Sep 26, 2013 7:05 pm
I think the 74HC will work just fine. Sure, HCU's are more linear and work from rail to rail, but for beeps and bloops it should work just fine(?) I will test it.
EDIT:
The famicom uses a 74HC368 for its sound.
Last edited by
yxkalle on Thu Sep 26, 2013 7:18 pm, edited 1 time in total.
-
l_oliveira
- Posts: 407
- Joined: Wed Jul 13, 2011 6:51 am
- Location: Brasilia, Brazil
Post
by l_oliveira » Thu Sep 26, 2013 7:13 pm
yxkalle wrote:I think the 74HC will work just fine. Sure, HCU's are more linear and work from rail to rail, but for beeps and bloops it should work just fine(?) I will test it.
HC won't work because it "won't oscillate"... I mean it won't amplify anything. I tried some and it didn't go well. Nintendo used HCU for a reason and I understood when I tried to mimic their circuit. Well try it and let us know how it goes !

-
aodinets
- Posts: 11
- Joined: Mon Feb 20, 2012 3:47 pm
Post
by aodinets » Sun Sep 29, 2013 6:35 am
Jarhmander wrote:Yes, I did exactly that and it works. Interestingly, R/W doesn't really work on this chip and it is not possible to read it, so there will never be bus conflicts with reads with this chip.
Beware: the output is quite weak and is only able to source current; it can't sink current.
Hi, all!
What do you think about this schematic with YMZ284 sound?
-
Attachments
-

Last edited by
aodinets on Mon Oct 07, 2013 4:21 pm, edited 1 time in total.
-
l_oliveira
- Posts: 407
- Joined: Wed Jul 13, 2011 6:51 am
- Location: Brasilia, Brazil
Post
by l_oliveira » Mon Oct 07, 2013 7:27 am
Lacks an amplifier. Even if the logic is fine the sound will be too low on volume.
-
aodinets
- Posts: 11
- Joined: Mon Feb 20, 2012 3:47 pm
Post
by aodinets » Mon Oct 07, 2013 9:17 am
l_oliveira wrote:Lacks an amplifier. Even if the logic is fine the sound will be too low on volume.
Amplifier is not a problem. Logic is important...
-
l_oliveira
- Posts: 407
- Joined: Wed Jul 13, 2011 6:51 am
- Location: Brasilia, Brazil
Post
by l_oliveira » Mon Oct 07, 2013 9:30 am
aodinets wrote:l_oliveira wrote:Lacks an amplifier. Even if the logic is fine the sound will be too low on volume.
Amplifier is not a problem. Logic is important...
Did you try building that ? I never tried that particular chip. I did try the GI AY-3-8910 and YM2149. Nothing else. The logic would be different depending on how the enable works for your chip.
-
yxkalle
- Posts: 62
- Joined: Sun Jan 27, 2013 7:30 pm
Post
by yxkalle » Mon Oct 07, 2013 10:45 am
I was under the impression a clock divider wasn't needed? If you look at the data sheet you can see a clock divider in the block diagram. Can someone spread some light on this?

-
l_oliveira
- Posts: 407
- Joined: Wed Jul 13, 2011 6:51 am
- Location: Brasilia, Brazil
Post
by l_oliveira » Mon Oct 07, 2013 10:49 am
yxkalle wrote:I was under the impression a clock divider wasn't needed? If you look at the data sheet you can see a clock divider in the block diagram. Can someone spread some light on this?

I did not need any when I used the YM2149. AY-3-8910 did require it.
-
infiniteneslives
- Posts: 2100
- Joined: Mon Apr 04, 2011 11:49 am
- Location: WhereverIparkIt, USA
-
Contact:
Post
by infiniteneslives » Mon Oct 07, 2013 11:16 am
Neither the 8910 nor the 2149 is self sufficient, but they're each lacking different things.
AY-3-8910: You must add a clock divider since it doesn't have one built in. However it's output doesn't require an amplifier.
YM2149: Has built in clock divider, but has a weak output so you have to add an amplifier.
Both require the same address decoder.
If you're gonna play the Game Boy, you gotta learn to play it right. -Kenny Rogers