Improving C-64 Audio
Crackers
Okay, here's a question. The C-64 has extremely noisey audio. There are a
lot of high freaquency chirps and buzzes going on in the background whenever
the SID chip is turned on. It sounds like it's some sort of processor noise
and you can hear it change as the machine performs different functions. Has
anyone ever found a way to eliminate this?
There was a synth module made recently (now discontinued) called the
SidStation that used a SID chip. Listening to some demos of the SidStation I
noticed it produced the same high freaquency interferance as that C-64. So
is this noise something something inherent in the SID itself?
It's a pitty Commodore never took the C-64's audio serious enough to
eliminate this background noise because that's the only flaw in what is
otherwise an increadable sound device.
And I'm still looking for any information on writing MIDI software for the
C-64. I've searched high and low on the internet and while I have found many
webpages with programming information, none of them address writing MIDI
software. Any help would be appreciated. Thanks.
Crackers
(Still adores his noisey SID chip from hell!!)
--
CrAB - http://www.hwcn.org/~ad329/crab.html
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Adam Dunkels
> Okay, here's a question. The C-64 has extremely noisey audio. There are a
> lot of high freaquency chirps and buzzes going on in the background
> whenever the SID chip is turned on. It sounds like it's some sort of
> processor noise and you can hear it change as the machine performs
> different functions. Has anyone ever found a way to eliminate this?
I usually hooked up my C64 to the TV through the RF-connection and had
those same problems. But I always thought that the noise might come from
interference with the video signal. The noise was worse with brighter
colors on the screen. It was even possible to play samples this way, by
setting $d011 to 0 and write sample data to $d020 (while going through
amplitude->brightness translation first).
> There was a synth module made recently (now discontinued) called the
> SidStation that used a SID chip. Listening to some demos of the SidStation
> I noticed it produced the same high freaquency interferance as that C-64.
> So is this noise something something inherent in the SID itself?
>
> It's a pitty Commodore never took the C-64's audio serious enough to
> eliminate this background noise because that's the only flaw in what is
> otherwise an increadable sound device.
Do you know if this was an old or a new SID chip? They might have improved
such things in the new SID chip. Sadly, the "improved" away the nice sample
output possibilities as well.
/adam
--
Adam Dunkels <ad...@dunkels.net> (That should be .com, not .net)
http://dunkels.com/adam/
Roland
>Do you know if this was an old or a new SID chip? They might have improved
>such things in the new SID chip. Sadly, the "improved" away the nice sample
>output possibilities as well.
I found a 'trick' (alternate filter setting) to play samples on the
new SID chip with a boosting volume.
You can hear it in one of my demo's which I made 10 years ago.
It's called 'Rave the Scene' from Silicon Ltd.
Downloadable at ftp.scs-trc.net (just find the Silicon Ltd directory)
Oh, you have permission to view the code ;-)
Later,
Roland
(scout/silicon ltd :)
---
f:un[x]iun
http://funxiun.2y.net
http://www.mp3.com/fnx
---
Adam Dunkels
> I found a 'trick' (alternate filter setting) to play samples on the
> new SID chip with a boosting volume.
> You can hear it in one of my demo's which I made 10 years ago.
> It's called 'Rave the Scene' from Silicon Ltd.
> Downloadable at ftp.scs-trc.net (just find the Silicon Ltd directory)
IIRC, you could also set the sustain and release of all chanels to $ff and
the test and gate bits ($09) in the waveform registers to hear the samples
on the new chip.
But this only works with no other sounds, so all the great 3 channel +
samples tunes still doesn't sound as good as they should :-(
> Oh, you have permission to view the code ;-)
:-)
Juergen Oppermann
Crackers wrote:
>
> Okay, here's a question. The C-64 has extremely noisey audio. There are a
> lot of high freaquency chirps and buzzes going on in the background whenever
> the SID chip is turned on. It sounds like it's some sort of processor noise
> and you can hear it change as the machine performs different functions. Has
> anyone ever found a way to eliminate this?
databus eg with an TTL74245 bi-directional driver, that only connects
the 6510 lines to the SID if selected. same goes for the address and
controll-lines eg 74573.
however you even more improve by use a separate powersupply
as the VIC/CPU noises, even floppy noises are induced into ground,
i once tried even an opto-isolated connection: CLEAN (: but it wasnt
bi-directional, so reading from SID did not work for a few tunes.
> There was a synth module made recently (now discontinued) called the
> SidStation that used a SID chip. Listening to some demos of the SidStation I
> noticed it produced the same high freaquency interferance as that C-64. So
> is this noise something something inherent in the SID itself?
afaik they use this same kind of buffering as well.
so what you refer to are the SID internal noises.
an OSC does not switch off entirely after a gate off. so you still
hear it slighly playing.
unless you do not hack your tunes by yourself there's no way of
reducing that, by re-setting the OSC-regs.
> It's a pitty Commodore never took the C-64's audio serious enough to
> eliminate this background noise because that's the only flaw in what is
> otherwise an increadable sound device.
yup, according to rob yannes there was neither time, nor interest in that.
thx heaven he was a synth enthusiast else we'd got another compi with
yamaha SQR-port-player like the Ataris.
> And I'm still looking for any information on writing MIDI software for the
> C-64. I've searched high and low on the internet and while I have found many
> webpages with programming information, none of them address writing MIDI
> software. Any help would be appreciated. Thanks.
you refer to the midi- protocol !?
http://www.borg.com/~jglatt/tech/miditech.htm
or look fpr some atari ST books in the libary - that's a TOP SECRET TIP !!!
WWW is not always THE solution a libary still bears lots of surprises.
--
* Jürgen Oppermann
* http://www.joogn.de
* Atari - 68K, C64 - SID, Charisma - Musik, ...
keith Snyder
noise (unless I programed it to) and i've had 3 C64s
Crackers
"keith Snyder" <keit...@webtv.net> wrote in message
news:5247-3AC...@storefull-177.iap.bryant.webtv.net...
> must be in your sid or C64,i've never heard any sid make that kind of
> noise (unless I programed it to) and i've had 3 C64s
Well you're a lucky man, because I've never heard a C-64 without a lot of
hiss and squeal in the audio.
Crackers
(Wish I had a low S:N ratio from hell!!!)
Crackers
"Juergen Oppermann" <jo...@gmx.li> wrote in message
news:3AC4FEA0...@gmx.li...
> yup, according to rob yannes there was neither time, nor interest in that.
> thx heaven he was a synth enthusiast else we'd got another compi with
> yamaha SQR-port-player like the Ataris.
Yeah the SID chip was the main reason I wanted the C-64 at all. Even with
the noise and interference it's still one heck of a cool sounding beastie.
> you refer to the midi- protocol !?
> http://www.borg.com/~jglatt/tech/miditech.htm
>
> or look fpr some atari ST books in the libary - that's a TOP SECRET TIP
!!!
> WWW is not always THE solution a libary still bears lots of surprises.
Thanks!
Crackers
(tangled in midi cables from hell!!!)
Crackers
"Adam Dunkels" <ad...@dunkels.net> wrote in message
news:rJ2x6.4331$4N4.9...@newsc.telia.net...
> Do you know if this was an old or a new SID chip? They might have improved
> such things in the new SID chip. Sadly, the "improved" away the nice
sample
> output possibilities as well.
The SidStation was built by a couple of guys in Sweden who had found what
was possibly the last remaining cache of brand new SID chips on the planet
and said
"Hey let's build a synth module with them".
I think there were just over 1000 SidStations built. It'll probably be quite
the collector's item synth some day even though it didn't have any better
audio than the C-64 and it should be entirely possible to write a C-64
program which functions as good as, if not better than, the SidStation.
It looked like a really neat idea, but like I said, when I listened to the
samples it was clear it suffered from the same noise interferance as the
C-64.
Oh well as long as your not playing soft passages that noise gets burried in
the background. I've done some recording with the C-64 being used as a synth
and the noise was only a problem during quiet passages or if the C-64 was
(supposed to be) sitting silent. A good noise gate would likely take care of
that problem.
Crackers
(gated from hell!!!!)
Christian Link
wrote:
>Well you're a lucky man, because I've never heard a C-64 without a lot of
>hiss and squeal in the audio.
How come I simply can't overcome myself to blame it for that...?
Cameron Kaiser
>Well you're a lucky man, because I've never heard a C-64 without a lot of
>hiss and squeal in the audio.
Possibly have the volume up too high? You can practically hear CPU activity
if you have the volume blaring -- try typing in a simple FOR-NEXT loop and
listen to the frequencies and tones in the backgrounds warble.
--
Cameron Kaiser * cka...@stockholm.ptloma.edu * posting with a Commodore 128
personal page: http://www.armory.com/~spectre/
** Computer Workshops: games, productivity software and more for C64/128! **
** http://www.armory.com/~spectre/cwi/ **
Miika Seppänen
>>
>> Okay, here's a question. The C-64 has extremely noisey audio. There are a
>> lot of high freaquency chirps and buzzes going on in the background whenever
Are you using a RF-connection on your C64? I've found an incredible
difference in voice quality when using the video-out connector instead
of RF. I guess it's the RF-modulator, that produces much of the noise.
-Miika
Crackers
"Miika Seppänen" <miks...@sci.fi> wrote in message
news:3ac5b304...@uutiset.saunalahti.fi...
> Are you using a RF-connection on your C64? I've found an incredible
> difference in voice quality when using the video-out connector instead
> of RF. I guess it's the RF-modulator, that produces much of the noise.
No, I use a composite monitor and run the audio to my studio gear. The C-64
just has a high noise:signal ratio. It becomes even more apparent when
you're not running it through the small speakers of a TV or monitor.
Crackers
(Noisey lil' bugger from hell!!)
keith Snyder
monitor;also I never crank the volume up extremely high;I have heard
noise in voice samples,but it came from the tape I recorded the voice on
not from the sid
Juergen Oppermann
a 4 bit sample could have on a C64 (;
--
* Jürgen Oppermann
* http://www.joogn.de
* Deep Thought Systems Present "The Answer to all Questions" of the Day:
* 41,9999999999 (Powered by InTeL Pentium)
Dag Lem
You can kill much of the noise from the VICII by blanking the screen
(clear bit 4 of $d011).
--
Dag Lem <re...@nimrod.no>
Crackers
"Dag Lem" <re...@nimrod.no> wrote in message
news:ud1yrcc...@sid.nimrod.no...
> You can kill much of the noise from the VICII by blanking the screen
> (clear bit 4 of $d011).
Well that's certainly a useful bit of information.
Crackers
(Blank screens from hell!!!)
Matthew Montchalin
|> There was a synth module made recently (now discontinued) called
|> the SidStation that used a SID chip. Listening to some demos of the
|> SidStation I noticed it produced the same high freaquency interferance
|> as that C-64. So is this noise something something inherent in the SID
|> itself?
|
|afaik they use this same kind of buffering as well.
|
|so what you refer to are the SID internal noises.
|an OSC does not switch off entirely after a gate off. so you still
|hear it slighly playing.
For which reason you should set the ADSR envelope appropriately (no,
not the same envelope that you use to generate the sound), trigger
it, let it decay down to a zero sustain, then after it is done, set
the respective TEST bit of register 4 for each voice so that you can
start the SID back up from an initial state.
Matthew Montchalin
|must be in your sid or C64,i've never heard any sid make that kind of
|noise (unless I programed it to) and i've had 3 C64s
Most of these people who claim their SIDs are noisy have never bothered
to turn off the SID by setting the TEST bits for each voice. Turning
the volume is not enough. You've got to disengage the voices by
setting the TEST bits in register 4.
I trust Jeri Ellsworth will be working on a SID replacement board
as well as her graphics accelerator board...
White Flame (aka David Holz)
I always cranked up the speaker in my SX64 and listened to my lengthy BASIC
programs run. I could tell the difference between the different FOR loops
by the sound of the noise that came out. :)
--
White Flame (aka David Holz)
http://fly.to/theflame
<Watch for spamblock when e-mailing>
ni...@dcs.ed.ac.uk
: I trust Jeri Ellsworth will be working on a SID replacement board
: as well as her graphics accelerator board...
I don't know if that would be her forte. She sounds like a
computer/digital type. The best person to design a SID replacement is an
analogue synth expert...
--
Serious, business-type email for life: niall_...@bigfoot.com
Hotmail is giving me serious gip, and moremail appears to have folded
without even a courtesy notice, so you'd best use the bigfoot address
if you feel like getting in touch.
Email address that'll be out of date next year: ni...@dcs.ed.ac.uk
Crackers
"White Flame (aka David Holz)" <whitef...@y.a.h.o.o.c.o.m> wrote in
message news:9abnom$21q$1...@barad-dur.nas.com...
> I always cranked up the speaker in my SX64 and listened to my lengthy
BASIC
> programs run. I could tell the difference between the different FOR loops
> by the sound of the noise that came out. :)
Hahahahah! SID interference being used as a TRON function. Heheheheh I love
it.
Crackers
(It's not a bug it's a feature from hell!!!)
Matthew Montchalin
Yes, and black screens are quieter than white screens, come to think
of it.
Ville Jouppi
wrote:
>I trust Jeri Ellsworth will be working on a SID replacement board
>as well as her graphics accelerator board...
I should hope (if that will be implmemented, that is) that it's just a board
where you can move your existing SID chip off the motherboard for better
isolation! I want to hear the real thing.
--
CBM, PEZ, and TI-calc nut, Scout, Glider pilot, Programmer
Email: vjo...@sci.fi, URL: http://www.sci.fi/~vjouppi/
GSM: +358-40-5679999, IRCNet: Jope
"I see", said the blind man as he picked up his hammer and saw.
Matthew Montchalin
|On Mon, 2 Apr 2001 16:12:38 -0700, Matthew Montchalin <mmon...@OregonVOS.net>
|wrote:
|
|>I trust Jeri Ellsworth will be working on a SID replacement board
|>as well as her graphics accelerator board...
|
|I should hope (if that will be implmemented, that is) that it's just
|board where you can move your existing SID chip off the motherboard
|for better isolation! I want to hear the real thing.
(Well, that *would* be nice.) -But what I really want is having access
to lots of SIDs, all addressed at $d400, each one selected according to
a configuration register somewhere else (or maybe at $d41f). A souped
up "Big Brother" to the C-64 ought to have stereo output, with at least
one SID routing its output to each stereo jack. Now, having two SID like
devices going to each output, that would be pretty nifty, and properly
driven, awe-inspiring.
Peter Karlsson
"White Flame \(aka David Holz\)" <whitef...@y.a.h.o.o.c.o.m> writes:
> I always cranked up the speaker in my SX64 and listened to my lengthy BASIC
> programs run. I could tell the difference between the different FOR loops
> by the sound of the noise that came out. :)
I didn't go as far as hearing the program contents, but I did learn
to adjust the azimuth angle just by hearing the noise, in order to
avoid the infamous "load error" message. :-)
--
Peter Karlsson
Integration & Verification
WCDMA & PDC Products
Ericsson Microwave Systems AB Phone: +46 31 747 00 00
Flöjelsbergsgatan 2 A Direct: +46 31 747 06 48
SE-431 84 Mölndal Sweden Fax: +46 31 706 75 72
www.ericsson.se/microwave Mobile: +46 709 87 06 48
Nate / DAC
> (Well, that *would* be nice.) -But what I really want is having access
> to lots of SIDs, all addressed at $d400, each one selected according to
> a configuration register somewhere else (or maybe at $d41f). A souped
> up "Big Brother" to the C-64 ought to have stereo output, with at least
> one SID routing its output to each stereo jack. Now, having two SID like
> devices going to each output, that would be pretty nifty, and properly
> driven, awe-inspiring.
Hm, maybe I should get back to work on PowerSID...
--
/~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\
| _ _ _|_ _ _| _ _ /~\ | _ _ _ |_ | _ _ _ ._ _ C64/128 - |
| |/ \'_| | /_)/ |'_|/ `| (Y |/(_`/ `'_|| \|/_) / `/ \| | | What's YOUR |
\_| |(_| |_\_.\_|(_|\_. \_. |\._)\_.(_||_/|\_.O\_.\_/| | |___Hobby??__/
Matthew Montchalin
|Matthew Montchalin <mmon...@oregonvos.net> wrote:
|
|> (Well, that *would* be nice.) -But what I really want is having access
|> to lots of SIDs, all addressed at $d400, each one selected according to
|> a configuration register somewhere else (or maybe at $d41f). A souped
|> up "Big Brother" to the C-64 ought to have stereo output, with at least
|> one SID routing its output to each stereo jack. Now, having two SID like
|> devices going to each output, that would be pretty nifty, and properly
|> driven, awe-inspiring.
|
|Hm, maybe I should get back to work on PowerSID...
Four SIDs with four output jacks might be pretty incredible, too. :)
Matthew Montchalin
||Hm, maybe I should get back to work on PowerSID...
|
|Four SIDs with four output jacks might be pretty incredible, too. :)
Of course, it would be CHEATING to use "real" SID's, what with them
no longer in production. What I want (and there is nothing wrong
with dreaming) is a plug-in replacement gizmo with lots more voices
than the original SID, and yet software compatible with (most) ordinary
software. I think that address $d41f is the most innocuous address
to decode for selecting additional sets of voices. Most people zero
it out, anyway, and that would default to SID 0 as opposed to any of
the other SID's I was contemplating.... It would be SO cool.... I
wonder how big and cumbersome a SID replacement card would have to be,
to do all that...
Nate / DAC
> |Hm, maybe I should get back to work on PowerSID...
>
> Four SIDs with four output jacks might be pretty incredible, too. :)
How about *eight* SIDs, bus-isolated, with the possibility to move any SID
(as a whole) to any (one or more) of the four channels via an external
mixer chip?
That's the plan if I ever get 'round to building it. The mixer chip and
bus isolators are David Wood's idea, and damn good ideas they are too ;)
I'd like to work on putting the device ANYWHERE in the memory map, but I
might be lucky to just get it to work at one of the more common I/O slots.
Nate / DAC
> the other SID's I was contemplating.... It would be SO cool.... I
> wonder how big and cumbersome a SID replacement card would have to be,
> to do all that...
I want to try to get this beast down to about the size of a Super CPU with
the SuperRAM card mounted on it - i.e. two boards mounted together. The
second board might hold one or two SID chips, and/or any of the other
little add-ons I want to build (DAC's, ADC's, and an MP3 chip).
Of course I still need to finish the MP3 decoder first (user-port device,
pump an MP3 file to it raw and it decompresses, decodes, and plays it all
in one step through it's own DAC).
Matthew Montchalin
|Matthew Montchalin <mmon...@oregonvos.net> wrote:
|> |Hm, maybe I should get back to work on PowerSID...
|>
|> Four SIDs with four output jacks might be pretty incredible, too. :)
|
|How about *eight* SIDs, bus-isolated, with the possibility to move
|any SID (as a whole) to any (one or more) of the four channels via
|an external mixer chip?
Sounds okay to me, so long as the gizmo-card assembly is emulating SID
chips. :)
|That's the plan if I ever get 'round to building it. The mixer
|chip and bus isolators are David Wood's idea, and damn good ideas
|they are too ;)
Fascinating...
|I'd like to work on putting the device ANYWHERE in the memory map,
|but I might be lucky to just get it to work at one of the more common
|I/O slots.
If you have the thing replace the SID at $d400, that would make me
pretty happy. In fact, I'd like to bring in all of the alternate
SID's into $d400, depending on how a configuration register is setup.
More headache for the engineer, less headache for the programmer.
Matthew Montchalin
|a Super CPU with the SuperRAM card mounted on it - i.e. two
|boards mounted together. The second board might hold one
|or two SID chips, and/or any of the other little add-ons
|I want to build (DAC's, ADC's, and an MP3 chip).
Nix on the requirement that we have original SID chips. They
aren't being manufactured anymore. Sure, people in big cities
might be able to scavenge 'em off of dead C-64's, but the rest
of us are at an extreme disadvantage.
|Of course I still need to finish the MP3 decoder first
|(user-port device, pump an MP3 file to it raw and it
|decompresses, decodes, and plays it all in one step through
|it's own DAC).
How far along are you?