Wilba
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Posts posted by Wilba
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If they are unused with working filters, I might be interested. What revision are they?
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Well it's nice to know you've really explored (and exhausted) all options. Kudos to you for giving as much time and effort in trying to fix the infamous envelope bug.
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Jess: I did a lot of checks with the Delay parameter in conjunction with a controlled ADSR reset
The last algorithm I tried was:
o on Note On clear the gate and clear ADSR, start the delay counter
o after the delay has passed (e.g. 33 mS or more), refresh ADS, R remains 0, set gate
o before the gate is cleared, refresh R as well
In general this allows to reset the EG, but the delay bug still can happen. Not so frequently anymore, but sometimes. And I've also an explanation for this: if the EG is still in decay phase (sustain level not reached), and we switch into the release phase by clearing the gate bit, the new compare value for the rate counter can be lower than the compare value used during decay phase -> a counter overrun will happen -> 33 mS additional delay
I've observed that raising the sustain will cause a decay at a rate relative to the decay value. Can this be exploited somehow? Probably not, I but thought I'd mention it anyway.
If the delay is just totally unavoidable, is it possible to reduce it as much as possible by speeding up the clock to the SID during this period?
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If a reset from the reset pin doesn't reset these counters, would it be possible to do a reset by temporarily cutting the Vcc (5v) supply, but leaving the Vdd (9v/12v) supply on? I know this is a drastic measure that would involve hardware changes, but it seems like if you're considering a "hardware reset" by toggling the reset pin and having to send all the registers every gate on, then you're willing to consider something as crazy as this. (I am at least, but I'd prefer a second opinion before pulling the 5v supply from my precious SIDs!)
Maybe just turning off the Vcc for a millisecond will not cause an audible pop, since the supply to the audio section is uninterrupted. Just a theory based on my limited knowledge of SID internals :-) I know it's not a very elegant solution, and one that would involve wiring a transistor to a spare shift register output perhaps... but maybe some people would think this worth the effort...
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After a second listen, the patch starting at 2:25 is very, very cool...
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Sorry to interrupt the drool fest, but reading Razmo's ideas about eliminating the envelope bug had me thinking... and an idea popped into my head.
If it's only the decay and release not being zero that causes the bug, can you setup the envelope on the SID to have zero decay and release, and max sustain, and then let the PIC lower the sustain value to emulate the decay and release phases? I'm already aware that you can't raise the sustain value while the oscillator is gated on, but you can lower it... i.e. you would set the sustain value to max, wait for the attack phase to finish, then lower sustain down to the "real" sustain value, then when the release phase should start, drop sustain down to zero. This would be much like the ENV2->Vol solution, except controlling sustain after the oscillator's attack phase is finished. From memory, I think my experiments with dropping the sustain value didn't suffer the clicking that dropping the volume register produces... plus this idea would have the added advantage of being per oscillator. (You would still need the "no gate off" option, and need it a little smarter, so it does gate off just before the gate on to trigger a new attack phase).
I'm not able to try some experiments with a wavetable controlling sustain right now, (i.e. I would have preferred to prove the theory before mentioning the idea)... so please excuse me for rambling on if it turns out not to be a feasable idea.
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Nice demo... I particularly like it at 3:58 and after...
It's also nice to know that my 8580 setup is just as noisy... the high-pitched digital noise that is...
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I just had a play with this ENV2->Vol option and it's fantastic! Now I can do things that were just too hard or impossible to do by modulating the volume register with the wavetable. Now you can modulate ENV2 depth (or just sustain) using a wavetable... and the effects are so cool...
Here's something similar to the Trancegate patch (in Wavetable Sounds Tutorial #2) to use ENV2 depth instead of filter cutoff.
Enable ENV2->Vol option.
Assign track 1 of the Wavetable to CC#79 (ENV2 Depth).
Set ENV2 Depth to 32, Atk 13, Dec 0, Sus 127, Rel 65.
Adjust the Wavetable Rate to 94 and enter following sequence:
STEP CMD #1
00 Play +20
01 Play -20
02 Play +20
03 Play -20
04 Play +20
05 Play +00
06 Play +00
07 Play -20
08 Goto 00
[/code]Now you can tweak the filter for your own purposes, and get fading in and out, since you can now use attack and release phases.
Unfortunately, the combination of leaving the gate on and poly mode doesn't work well... if you play three notes, and then just one, you'll hear two of the notes previously played.
P.S. I hope for MB-SID v2, it's possible to just add the volume register as a modulation target, so any envelope or LFO can modulate it.
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This place has a lot of screws... it might be in there...
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When you want to upload new firmware to your MB-SID slave PICs (see bottom of this page here), you either do it using "the Newbie method" way (put PIC into a core with optocoupler and MIDI In/Out connected to PC, or move optocoupler and MIDI In/Out connections to the slave core) or using "the Expert method" (select the "Don't use feedback from core" option in MIOS Studio, enable MIDI merger with the Link button, and pray it doesn't get corrupted).
However, you can use the "Expert method" and use feedback from the core if you simply move your MIDI Out cable to the MIDI Out port of the slave. In theory, you could also use this method to upload a new MIOS version, if you're able to reset just the slave after enabling the MIDI merger with the Link button on the master, even using the "Wait for upload request" feature.
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"Free to a good home" means they're free, no need to trade.
You'll have to pay for postage from Australia though...
I'll send a private message with the details.
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Do you just want the keyboard part? i.e. keys, PCB with switch contacts?
I have five. Free to a good home.
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I got corrected today, but since there's more than one way of saying it, what's most common?
And is the "tim" in "multitimbral" a "tam" or a "tim"?
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I should also add that there's no consistent rule regarding the "value" versions not having YMF262 chips, or the non-"value" versions having YMF262 chips... visual identification seems to be the best way (i.e. don't even trust the CTxxxx model number!)
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Where did you get your SID chips? You cannot assume that all your chips aren't dead.
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This has some nice, hi-res pictures of various Sound Blaster/Vibra 16 and other sound cards, so when shopping on eBay you can at least compare the eBay photo with this. Pictures are of high enough res to identify the Yamaha chips.
http://museum.gravisultrasound.net
I can't understand any of the text, so I have no idea WHY this person is cataloging old sound cards.
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[*]the internal WT editor now allows to modify the parameters of a whole track at once, this speeds up the initialisation of a new WT sequence. Just select the position beyond 31 ("All" will be print) and modify the Mod, #1, #2 or #3 column
This was just a crazy idea I had when I got tired setting a whole track to zeroes. I can't believe you liked it so much you put it in this build! Thanks!
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OverClocked ReMix - Unofficial Game Music Arrangement Community
It was here that I discovered a remixer who obviously likes the Dune computer game soundtrack (aka. the Dune: Spice Opera CD) by Stephane Picq as much as I do:
I might as well also add that I love Dune: Spice Opera and think others here would also...
Since you cannot buy the Dune: Spice Opera on CD anymore, you can download the MP3s here:
http://olivier.dri.free.fr/dunedown.php3
Try "Free Men" first... my favourite.
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You can drive two or more LEDs in series, but since we're talking about LEDs being driven from a DOUT, which outputs 5v, the combined voltage drop must be less than 5v. Blue and white LEDs will have a voltage drop of 2.75v or more, so you can't drive two in series with 5v.
I was just suggesting the more generic solution, but pay_c is right - if possible, put them in series as the current draw is less than if you put them in parallel - i.e. you can drive two in series for the same current as just one... view it as exploiting the fact that you've got 5v x 20mA to work with.
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Please read here: http://www.kpsec.freeuk.com/components/led.htm
and scroll down to "Avoid connecting LEDs in parallel!"
If you join them in parallel, you will need a resistor for each LED.
You might want to put a bridge in the DOUT instead of a 220 Ohm resistor, connect each LED's anode to the DOUT output pin (single wire), and then put the two resistors between each LED's cathode and ground.
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The last time that guy sold 4x 6581s, the winning bid was $49.
Now the minimum bid is $100.
Personally, I would stay clear of '82 and '83 SIDs, as I have had the worst luck with them.
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Sorry, I didn't mean to imply it was a good idea to remove the copyright notice, we all respect TK's work and most would not even think of removing the copyright notice because of that respect. My point was just that changing MIOS to achieve a particular effect (in this case, changing the boot screen) is not illegal, as (I believe) you would not be breaking copyright laws, no more than you would by writing your name on the first page of a printed book. Perhaps I'm wrong, and I have a lot of contraband on my bookshelf!
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I really appreciate the offers, thanks... However, I have already bought 4x 8580s from Reflex Audio (the guy posted on this forum here). They sell HardSID cards as well. He was kind enough to let them run overnight and test them thoroughly before shipping. Worth the premium price of US$30 each, inc. postage. I haven't put them in yet, as I also salvaged an 8580 from a C64C recently, which is working beautifully. Now my MBSID box is set up for 4x 8580s and I am fully stocked and stoked ;D
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I don't think it's illegal. MIOS is open source to the degree you can tinker all you like with it for your own personal use. So modify the MIOS source, no one is stopping you. If you need more help than that, you shouldn't be attempting it at all.
MB SID V2 discussion?
in MIDIbox SID
Posted
This has already been done... sidplayer_v1b.zip is firmware that uses the same protocol that the SidStation uses to play SID files, so you can use the ASID player (on a PC) to play SID files through your MB-SID setup. While it would be a nice thing to have this protocol in MB-SID v2 (so you don't need to swap firmware), I'd prefer that memory used for synth features.
On a related topic: TK, could the current sidplayer app route the incoming SysEx messages to the slave PICs (in a 2+ SID setup) and thus play SID files in stereo? I'm suspecting it would be just a one line change, but I'm not able to try it out at the moment.