adding an FM soundchip to the ST?

[Nyh]

@bullis1->Yeah FM cartrige???Can You post please name of that cartrige?It is sure MIDI compatible...That is cool!!!

Sorry, my post was not clear. I have many cartridges for digital sound tracking. I do not have an FM cartridge for ST. For FM sound on ST, I use a Yamaha FB-01 module. It is MIDI controlled, and very cheap. It also has good software for ST called YSEDITOR to program the synth.

So the is a very cheap solution for adding FM sound on the ST, even comes with excellent software.

Problem solved!

Hans Wessels

[bullis1]

So the is a very cheap solution for adding FM sound on the ST, even comes with excellent software.

Problem solved!

Hans Wessels

But you are so wrong. No tracker supports it, only MIDI software. Therefore, you do not get the maximum control over the chips that you can with tracker/cartridge type setups. While you can do patch changes, pitch bends, and the typical stuff, you do not have the possibility of any advanced effects found in trackers. It is really not the same unfortunately.

[earx]

haven't visited this board for a while but Tinctu's post seemed really nice! it would be great if that turbosound could be adapted to the ST. sadly, my hardware design skills are lacking and soldering is also limited to switch/wire/connector (simple) type of stuff

MrNi: oh, come on.. not that much demos being written for the ST? excluding a zillion intros there were 3 big ones last year. and the chipmusic scene is booming! there are more people poking the AY and YM than ever.

[Stefan jL]

The "enhanced PSG" AY8930 would be an easy upgrade in the ST... just solder off the YM and put in the AY.
AY8930 works fine with the ST i just tested, but some changes to the soundcircuit (caps and resistors) might be needed to make the sound more clear.
I have no idea what the "enhanced" features are of the AY8930 since there is no software that makes use of them.

Sorry for editing your post. I don't usually edit users posts, but I wanted to emphasize the problem with adding soundchips, or even replacing the old one... If you feel offended, let me know and I restore your message the way it was (Without bold text)// Greenious

[simbo_backdoor]

placing a larger electrolytic cap on the supply pin of crap sounding chips usualy fixes them to sound better
if your stf doesnt sound so good simply port the sound via a graphic equaliser and cut off the top end to get rid of the system noise
this is usualy carried into the chip via its supply rails
and in atari isnt so well decoupled so noise gets into the sound chips power supply and corrupts the nice audio it should produce
many modern pc's even ones with 7.1 speakers and this and that card etc sound just as crap and full of noise
adding a decent current resoviour cures most of this up
if you supply the machines exact details ill tell you where to add the cap {st stf ste falcon} or even your pc....
this is fact
i recently changed this cap on my sblive an audigy and audigy2 also a unified main board {one that has sound and video built in
and just changing it for a decent one made a big differance
i then went on to add a decent hifi quality opamp to the line out and suround stages on the live and audigy and audigy 2
now its perfect with no noise and a super low level noise floor
a proper audio card
so i believe a similar opamp and cap mod to atari could be done on the cheep
and cheer up the sound
i site this place as an example http://forums.vr-zone.com/showthread.ph ... e&t=168831
and can recommend some of the mods also be done to ataris
forinstance the ste
change u504 u507 {quad opamps } for this chip in dil package ,,,, LME49740
add a 330uf @16v electrolytic to pin 40 of the sound chip {vcc connection}
add also 3 X 10nf resin dipped as close to the pin 40 pin 25 and pin 28 as possible and the other end's to ground
100nf ceramic type ste has isnt enought to stop all the system clicks pops and mouse movement wizzz....
you can get the LME chip from suppliers or from the maker on sample
{maybe they change there samples types the package supplied seems to change type at will}
i got four duals and 4 quads for about 25$ postage cost in smd but recently they will only supply pdip or dil
but man the chip to buy is £6 each {maybe 10 euros or so}
so i saved a packet for what i needed
attached is what me and my pal are working on just now it will be silver plated boards and solid sterling silver hookup wires to the pots and i/o
you can see the pictures in the archive attached below
but to view the designs youll need a demo of proteus vsm {www.labcenter.co.uk}
its just an example of what can be done with a little thought instead of replacing what is a good sound chip anyway
with not much better if you dont add these mods it will still sound bad
... in the design here we plan 3 boards per channel and one psu for a 6band notching parametric eq
using hifi buff quality chips instead of grotty pre 2000 era crap massmarket opamps
and is ment as an example of an older design revamped using modern chips
and a little few changes to the circuit ,layouts and materials used


........


dont forget if you mod this way with these opamps then you need to burn the chip in by leaving the machine running with audio for about 24hrs
to get the full chips glory

[Stefan jL]

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

[simbo_backdoor]

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 :/

[Greenious]

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.

[earx]

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.

[unseenmenace]

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.

[tinctu]

@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.

[Stefan jL]

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

[unseenmenace]

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

[Stefan jL]

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
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.

[unseenmenace]

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?

[Stefan jL]

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

[Atari Generation One]

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.

[bullis1]

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.

[simonsunnyboy]

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

[bullis1]

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).

[Stefan jL]

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

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.

[bullis1]

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

[earx]

that's interesting news

[Stefan jL]

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

[bullis1]

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.