adding an FM soundchip to the ST?

Troubles with your machine? Just want to speak about the latest improvements? This is the place!

Moderators: Mug UK, Zorro 2, Greenious, spiny, Moderator Team

User avatar
Stefan jL
Atari God
Atari God
Posts: 1297
Joined: Thu May 09, 2002 3:21 pm
Location: Sweden
Contact:

Re: adding an FM soundchip to the ST?

Postby Stefan jL » Mon Jan 28, 2008 9:13 pm

No i did not mean that the AY had more noise (or any at all, i did not hear any) ,what i ment was that putting the AY8930 in the ST makes the sound more soft/bass/muffled, i presume the volume is different from YM2149 thus making the need of changes on the soundcircuit.
Listen to this example: http://www.ym2149.com/ref/breath_ay8930_ym2149.zip
Image

simbo_backdoor
Atari User
Atari User
Posts: 37
Joined: Fri Jan 25, 2008 1:23 am

Re: adding an FM soundchip to the ST?

Postby simbo_backdoor » Mon Jan 28, 2008 10:48 pm

i understand that the older sound chip in st is monophonic becouse it has less oscillators and filters
and is passed much less data ....
so i know what it sounds like i have a few
i think like the normal sound with sand draning thru it from the poor sample rate FM

however its not the best sound output even from better ste and falcon machines
placing a more modern sound chip into an st /stf is fine but not easy to do ..
atari uses custom ic's to pass data around and this makes it hard to implement adding later hardware to the older circuit

so if you want better sound you need to add a cartrige otherwise use an ste or falcon
or better use steem and gain perfect sound ... @16bit or better
all i was saying is to replace a few opamp parts to get much better sound from ataris in general

i didnt want to talk about adding later sound ic's to atari st as there is much much better ic's that could now be added than the ones
in use in any atari machine however instructing them properly isnt possible so there extended features arent avalible

this addition would also mean that each game would have to be heavily patched

when most software is executed it first quieries the machine and sets up its software and the hardware registers to work a certain way

so a program expecting to command a monophonic 8bit FM chip and an st will NOT be able to perform the same task on a later ic implant
the data is very different to instruct the later ic in hardware
but in software its much the same as long as your software does what it needs to with the hardware
forinstance the sound ic in st machine resides at a different address and physical address its control registers are different and word structure
so .... its not possible without a heavy patch to all the software

and that i beleve is pie in the sky :/

User avatar
Greenious
Hardware Guru
Hardware Guru
Posts: 1462
Joined: Sat Apr 24, 2004 5:39 pm
Location: Sweden

Re: adding an FM soundchip to the ST?

Postby Greenious » Wed Jan 30, 2008 12:30 am

Replacing the existing PSG is questionable. Potential software issues would make it a boring exercise I think.

However, adding one, is not a bad idea, as long as some coders want to actually code something that lets people use it.

The PSG is mapped at $ff8800-$ff8802, on ST there also was shadow registers of the psg all the way up to $ff88fe, which a lot of coders (ab)used using movep, to quickly set up the sound registers.

However, you could map another soundchip elsewhere, maybe even hijack part of the $ff88xx space. (from $ff8880- ?).

Anyway, the technical aspect of this is not very hard, but unless some coders offers support for this, it is a worthless effort.

Existing games/demos are one thing, updating those is not of interest.

Future demos/games another thing, but I suspect the biggest "market" for this would be the chip musicians. Having access to more channels, maybe even FM sound, should be fun for these guys.
Updated my guides as of june 28th, 2016. Check'em out and feedback!
viewtopic.php?t=5040

User avatar
earx
Captain Atari
Captain Atari
Posts: 353
Joined: Wed Aug 27, 2003 7:09 am

Re: adding an FM soundchip to the ST?

Postby earx » Wed Jan 30, 2008 12:31 pm

Greenious, my point exactly. there is a huge amount of active chipmusicians out there. and when i hear what some japanese guys did with console/arcade/msx (FM) machines in the old days i can't help think what ST musicians could do with it. the atari xl/xe series also has a 2nd pokey extension. i don't know how they did that, but it sounds like a good place to look.

i agree with software issues. 99% h/w compatible means <50% software compatible in practice. so adding one would be safest.

User avatar
unseenmenace
Atari God
Atari God
Posts: 1961
Joined: Tue Sep 21, 2004 9:33 pm
Location: Margate, Kent, UK
Contact:

Re: adding an FM soundchip to the ST?

Postby unseenmenace » Thu Jan 31, 2008 8:46 pm

I've been reading the AY8930 datasheet and from what I understand the 8930 starts in AY8910 compatible mode and the 8910 is pin compatible with the YM2149 so swapping to an 8930 should pose no problems at all. Its no FM chip but once switched into 8930 mode it does add some interesting (though not groundbreaking) features including wider tone frequency range, independant Envelope shapes for the 3 voices and a more advanced noise generator so I would think it would be fairly easy to add support to an existing chip tracker such as MaxYMiser.
UNSEEN MENACE
Several STFM's, 4MB STE, 2MB TT with 1.2GB Hard Drive and 14MB Falcon with 540MB Hard Drive,
Lynx 2 and Jaguar with JagCD
Member of GamebaseST and AtariLegend team
Check out my website at http://unseenmenace.110mb.com

tinctu
Atarian
Atarian
Posts: 5
Joined: Fri Jan 18, 2008 1:16 am

Re: adding an FM soundchip to the ST?

Postby tinctu » Sat Feb 02, 2008 8:29 am

@Stefan ->
Send me any news of replace old YM to new AY8930 in ST project... /e-mail/
And "how can I do that..."!

What about simple PCB I mean with 2 slots one for YM and one for AY8930.
I mean as stereo upgrade.

I have one old 1040stf at home :)))...
/Its me from soundshock.../
Maybe somebody can write later e-mail to GwEm author of MaxYMizer to make some updates in MaxYMizer for AY8930 support.
:coffe:

User avatar
Stefan jL
Atari God
Atari God
Posts: 1297
Joined: Thu May 09, 2002 3:21 pm
Location: Sweden
Contact:

Re: adding an FM soundchip to the ST?

Postby Stefan jL » Sat Feb 02, 2008 1:04 pm

tinctu wrote:Send me any news of replace old YM to new AY8930 in ST project... /e-mail/
And "how can I do that..."!


Just solder off the YM and put the AY there instead :) I have added a socket in my ST so i can easily switch them.
But as you heard in the recordings i posted there is changes needed to be done on the soundcircuit and thats probably the major reason this will not be accepted as an sound upgrade, i'm not a musician or programmer so it's not up to me to make any decision to make what sound musicians want :wink:
I emailed Tao and he was not too enthusiastic about doing this beacuse of the muffled sound as more changes needed to be done.
Image

User avatar
unseenmenace
Atari God
Atari God
Posts: 1961
Joined: Tue Sep 21, 2004 9:33 pm
Location: Margate, Kent, UK
Contact:

Re: adding an FM soundchip to the ST?

Postby unseenmenace » Sat Feb 02, 2008 6:58 pm

Stefan jL wrote:I emailed Tao and he was not too enthusiastic about doing this beacuse of the muffled sound as more changes needed to be done.

I wonder if it would sound any better if you connected the output pins from the AY directly to a jack socket rather than going through the ST's sound circuitry at all? While you're at it you could make the channel combining switchable for stereo support :)
UNSEEN MENACE
Several STFM's, 4MB STE, 2MB TT with 1.2GB Hard Drive and 14MB Falcon with 540MB Hard Drive,
Lynx 2 and Jaguar with JagCD
Member of GamebaseST and AtariLegend team
Check out my website at http://unseenmenace.110mb.com

User avatar
Stefan jL
Atari God
Atari God
Posts: 1297
Joined: Thu May 09, 2002 3:21 pm
Location: Sweden
Contact:

Re: adding an FM soundchip to the ST?

Postby Stefan jL » Sat Feb 02, 2008 7:52 pm

unseenmenace wrote:I wonder if it would sound any better if you connected the output pins from the AY directly to a jack socket rather than going through the ST's sound circuitry at all?


I did that kind of test when i tried a AY8910 in my ST as it did also have that muffled sound, and of course the sound become nice when done that way :) But you need to lower the volume otherwise the sound will distort badly when the channels mixes... i put a resistor betwen soundsignal and ground.
The standard soundcircuit in the ST do already make the YM (or AY) distort because of the previous mention high volume channel mixing so doing an external soundcircuit could be a good idea for audiophiles :wink:
I don't know why Atari mixed the YM at so loud volume, but maybe to drown out the background noise more? The distortion can be heard clearly in music that are at high volume, I think Tao is one of the few composers who compose at low volume to get rid of this problem.

User avatar
unseenmenace
Atari God
Atari God
Posts: 1961
Joined: Tue Sep 21, 2004 9:33 pm
Location: Margate, Kent, UK
Contact:

Re: adding an FM soundchip to the ST?

Postby unseenmenace » Sat Feb 02, 2008 8:40 pm

Is your 8930 mod in an ST(fm) or an STE? I figured there may be a difference due to the STE mixing its YM output with the DMA sound so its possible it may sound better in one than the other?
UNSEEN MENACE
Several STFM's, 4MB STE, 2MB TT with 1.2GB Hard Drive and 14MB Falcon with 540MB Hard Drive,
Lynx 2 and Jaguar with JagCD
Member of GamebaseST and AtariLegend team
Check out my website at http://unseenmenace.110mb.com

User avatar
Stefan jL
Atari God
Atari God
Posts: 1297
Joined: Thu May 09, 2002 3:21 pm
Location: Sweden
Contact:

Re: adding an FM soundchip to the ST?

Postby Stefan jL » Sat Feb 02, 2008 8:46 pm

I have an STFM and i doubt it will sound better in an STE.
Image

Atari Generation One
Atarian
Atarian
Posts: 8
Joined: Tue Aug 22, 2006 10:19 am
Contact:

Re: adding an FM soundchip to the ST?

Postby Atari Generation One » Fri Feb 08, 2008 12:38 am

Hey guys, seems that is one of the most interesting and first "fancy hardware" upgrade for ST, with this it can even interest much more people than you could even think.

Theres also SID which is very interesting at all.

But the question is, is there anybody who can adapt it to ST/STE?

And i think its not needed to build it as external cartridge but internal board, even with new connectors.

User avatar
bullis1
Fuji Shaped Bastard
Fuji Shaped Bastard
Posts: 2301
Joined: Tue Dec 12, 2006 2:32 pm
Location: Canada
Contact:

Re: adding an FM soundchip to the ST?

Postby bullis1 » Fri Feb 08, 2008 2:58 pm

In the PC world, I have seen various sound chips controlled through the parallel port. The SID, the chip that's in the SNES, and the FM chip that's in the Sega Genesis. There have probably been more too. I'm sure this technique would be applicable to ST as well.

User avatar
simonsunnyboy
Moderator
Moderator
Posts: 5131
Joined: Wed Oct 23, 2002 4:36 pm
Location: Friedrichshafen, Germany
Contact:

Re: adding an FM soundchip to the ST?

Postby simonsunnyboy » Fri Feb 08, 2008 3:26 pm

Hooking it up is no problem...but having software taking advantage of the freshly connected chip is the main problem.
Simon Sunnyboy/Paradize - http://paradize.atari.org/

Stay cool, stay Atari!

1x2600jr, 1x1040STFm, 1x1040STE 4MB+TOS2.06+SatanDisk, 1xF030 14MB+FPU+NetUS-Bee

User avatar
bullis1
Fuji Shaped Bastard
Fuji Shaped Bastard
Posts: 2301
Joined: Tue Dec 12, 2006 2:32 pm
Location: Canada
Contact:

Re: adding an FM soundchip to the ST?

Postby bullis1 » Fri Feb 08, 2008 3:52 pm

simonsunnyboy wrote:Hooking it up is no problem...but having software taking advantage of the freshly connected chip is the main problem.


Well, the easiest way to test this is to code a player for dumps from that chip. It still requires coding, however. The SNES has SPC, the C64 has DAT/SID, and the Genesis has GYM. These are all similar to the old YM dumps for ST (that have since been replaced by a superior format, SNDH).

User avatar
Stefan jL
Atari God
Atari God
Posts: 1297
Joined: Thu May 09, 2002 3:21 pm
Location: Sweden
Contact:

Re: adding an FM soundchip to the ST?

Postby Stefan jL » Fri Mar 21, 2008 8:58 pm

I have got an email reply from gwEm, he is ATM not gonna add AY8930 support in maxYMiser but will very likely do it in the future as he wants to compose music right now and not code (maxYMiser had a big update recently)... also if i find a solution for fixing the soft/muffled sound the AY8930 had when put in the ST his motivation will boost he said for an maxYMiser update :wink:

He allowed me to post his reply at forum if i wanted... so here it is:

So some initial thoughts about it:

The expanded tonal range for the square wave will allow deeper bass
frequencies - thats something important, as the YM2149 is the ST could do
with an extra lower octave I think.
DIFFICULTY: Easy or Hard to include in maxYMiser. Its easy to add a few
useful extra bass notes, but using the whole range is likely to be very
challenging as of course I special-cased the whole note range to the
YM2149.

Having three envelope generators is a real joy. All sorts of nice things
will be possible - three channel sync buzzer for example - just to name
one.
DIFFICULTY: Easy. In fact alot of special cases exist to multiplex three
channels down to one real envelope.

Its possible to set the square wave duty cycles on all three channels
seperately. You could use this for very low CPU usage SID effects. By
setting these at fast rates, I can imagine some wild effects would be
possible.
DIFFICULTY: Hard. Big GUI change necessary - pain in the arse stuff.

There are two eight bit 'noise mask' registers.. Who can tell what sort of
effects could be achieved with those.
DIFFICULTY: Hard. Again, shitty GUI stuff.

Making YM2149 and AY3930 modes coexist in the same sound driver might be a
bit challenging. By allowing noise mask and duty cycle to be changed at
audio frequencies (with a timer) you might be able to get some cool stuff
- again its more work... But at least no GUI change would be needed for
that. maxYMiser timer routines have some mildly horrific devpac macros to
achieve decent speed considering their flexibility, its Medium difficulty
stuff.


a few extra notes:

you get an extra bit of amplitude precision - very useful indeed. Should
give the possibility for higher quality digidrums too.

you get three extra bits of noise period range. again - a welcome
improvement.
Image

User avatar
bullis1
Fuji Shaped Bastard
Fuji Shaped Bastard
Posts: 2301
Joined: Tue Dec 12, 2006 2:32 pm
Location: Canada
Contact:

Re: adding an FM soundchip to the ST?

Postby bullis1 » Mon Mar 24, 2008 5:51 pm

Thanks for letting us in on this Stefan. I've been playing with MaxYMiser a lot since the update, and I am always happy to hear about new tracking possibilities.

However, it is especially nice to hear that gwEm is going to focus on music for a while :)
Member of the Atari Legend team

User avatar
earx
Captain Atari
Captain Atari
Posts: 353
Joined: Wed Aug 27, 2003 7:09 am

Re: adding an FM soundchip to the ST?

Postby earx » Wed Mar 26, 2008 2:08 pm

that's interesting news :)

User avatar
Stefan jL
Atari God
Atari God
Posts: 1297
Joined: Thu May 09, 2002 3:21 pm
Location: Sweden
Contact:

Re: adding an FM soundchip to the ST?

Postby Stefan jL » Sat Apr 05, 2008 7:24 pm

I have checked a little about the soft sound of the AY8930 when put in the ST... it output about o.80v while the YM2149 output about 2.90v (checking with the same tune), i first thought the reason for the soft sound was taht the AY output was louder as the final amplified signal was louder from the ST but it turned out it was the other way round wich would not make it as easy to change the circuit... otherwise it would just to have been adding an resistor if it was the AY that was the loudest :?
Image

User avatar
bullis1
Fuji Shaped Bastard
Fuji Shaped Bastard
Posts: 2301
Joined: Tue Dec 12, 2006 2:32 pm
Location: Canada
Contact:

Re: adding an FM soundchip to the ST?

Postby bullis1 » Mon Apr 07, 2008 1:00 pm

So what you're saying is that it now needs some kind of amplifier instead of a resistor? That's kind of annoying. It wouldn't bother me as I have my ST patched into a Behringer mixing board, and I could amplify it from there but for most people that sucks. However, I'm thinking that only musicians would be interested in this mod anyway.
Member of the Atari Legend team

simbo

Re: adding an FM soundchip to the ST?

Postby simbo » Wed Apr 09, 2008 1:00 pm

i would use a varaible resistor {log type not a lin} like this{ 10k or 1k or 4.7k prob 4.7k is best}
.........out..............
..........|...............
in>>>\/\/\/\>>>ground

and couple the out to the circuit using a 10uf cap @16v

like
out>> -||+ >>amp

this way youll get rid of the dc offset one type gives

you can use some simple software to generate a 1khz sine from the channels @1db
and then using a tape player etc.... on most gear or amps to allow you to set the output to 1db

if you cant find a log type pot you can do this this will make a kind of log pot {good for audio}
....R1{pval/2}...out.......R2{pval/2}.....
in---/\/\/\--------|--------/\/\/\---ground
in-------------/\/\/\/\/\-------------ground
...............pot pval=4.7k
so R1/R2 os 2.2K {or 2.3 if you can get it but its no mater}
most pc's can use the mic audio in and yield an audio spectrum analyser
so you can be very precise with this software... it uses a leed to passback audio from the output stages to allow callibration of the software
look online for examples there are a few

User avatar
Stefan jL
Atari God
Atari God
Posts: 1297
Joined: Thu May 09, 2002 3:21 pm
Location: Sweden
Contact:

Re: adding an FM soundchip to the ST?

Postby Stefan jL » Fri Apr 11, 2008 10:41 pm

bullis1 wrote:So what you're saying is that it now needs some kind of amplifier instead of a resistor? That's kind of annoying. It wouldn't bother me as I have my ST patched into a Behringer mixing board, and I could amplify it from there but for most people that sucks. However, I'm thinking that only musicians would be interested in this mod anyway.


I was hoping it would work on STE also and there YM is mixed with DMA sound, so if an external amplifier is used then the DMA also need to go thru it. And yes this is probably more interesting for musicians (the micromusic scene) and those who want to use their real Ataris to listen to the music instead of emulators :)
Image

User avatar
bullis1
Fuji Shaped Bastard
Fuji Shaped Bastard
Posts: 2301
Joined: Tue Dec 12, 2006 2:32 pm
Location: Canada
Contact:

Re: adding an FM soundchip to the ST?

Postby bullis1 » Mon Apr 14, 2008 12:55 pm

Stefan jL wrote:I was hoping it would work on STE also and there YM is mixed with DMA sound, so if an external amplifier is used then the DMA also need to go thru it. And yes this is probably more interesting for musicians (the micromusic scene) and those who want to use their real Ataris to listen to the music instead of emulators :)


Right, I never thought of the STE. You can intercept the signal before it gets mixed, but I wouldn't know what trace it is.

So yes, this would be a good mod for people like me :thumbs:
Member of the Atari Legend team


Social Media

     

Return to “Hardware”

Who is online

Users browsing this forum: No registered users and 5 guests