9 replies to this topic

[Param1]

Hello Guys, I have a question.

I read a couple of times, here and there, warnings that SIDS are rare. For instance, Wilba states to not order a sammichSID unless you have one of the rare SID chips. I can not understand this but I am not as experienced as you guys. All I can say is that in Europe, every single day C64 & C128s pop up at Ebay and other sites. So I guess that like 99% of the chips of used C64 must be broken or something? I recently bought my first C64 from 1990 with a 1989 SID (nice how easy it is to get them out the socket) but I am not able to test the Chip yet.

So again, are many Chips broken or faulty? What about 8580 vs. 6581. The latter is very glitchy while the 8580 is not, right?

Edited by Param1, 21 January 2011 - 23:21.

[phunk]

a lot of the ebay sids are broken or have broken filters. Most of the sellers aren´t aware of the fact that the sid isnt 100% working just because
it makes any kind of sound. Trial and error ;)

8580 vs. 6581
9v - 12v
working filter - not really good working filter

[Hawkeye]

Well i guess i was really lucky - harvested 9 c64-ii from ebay (partially marked as broken and partially in really bad shape, all rotten and stuff) and obtained 8 fully working 8580s.
It is a big mess to vampire them though, really leaves bad karma traces.

Edited by Hawkeye, 22 January 2011 - 00:59.

[Param1]

Well i guess i was really lucky - harvested 9 c64-ii from ebay (partially marked as broken and partially in really bad shape, all rotten and stuff) and obtained 8 fully working 8580s.
It is a big mess to vampire them though, really leaves bad karma traces.

I agree about the Karma thing... it really sucks to harvest C64... C64 deserve hugs and not to be scavenged :-(
I think it is one of the most important computers and I hope that they survive as long as possible because they are an important cultural product of our society.

Regarding 8580 vs 6581: I just meant in regards to longevity. I know the different specs and filter characteristics

[Hawkeye]

Well i guess it does not matter - if the chips survived up to today, they will likely survive another few decades :-).
I have had only had good experiences with the 8580s, and as they run a little bit cooler than the 6581s, i´d expect them to have a higher life expectancy, but I guess nobody really has measured it ;-).
Btw, if you have a working C64, you can test the SIDs in there, of course.
And i totally agree about the most important computer, if a higher deity would send me to a deserted island (with ac mains power ofc) with only one technological device allowed, i would know what it would be, and it would not be my shaver ;-)

[Davo]

Regarding the question of whether a SID is good or not, what's a good test to use? Some C64 program to fully check everything? Some MIOS program to fully check everything?

[Hawkeye]

This one should do it in a real c64: http://mccormick.cx/projects/aSid/
mios - just the plain mbsid app will allow you to switch filters on and off and change the cutoff and resonance values.

[nILS]

Regarding the question of whether a SID is good or not, what's a good test to use? Some C64 program to fully check everything? Some MIOS program to fully check everything?

MIDIbox SID?

[Param1]

MIDIbox SID?

Yep, I would program a simple arpeggio with a midi sequencer, that includes the lowest and highest possible notes. Then I would play, loop it and assign it to OSC 1 of Chip 1. While the arpeggio runs, I would change the waveforms (inclduing combinations and noise) of the OSC 1. Then I would do filter sweeps including changes of the resonance with different filter setups (hp, lp etc.). Then I would change ADSR settings and listen to the results. Same for lfo's and the a few tests if the wavetable triggers changes correctly. Then all of this for the next OSC. I hope this makes sense.

Edited by Param1, 22 January 2011 - 16:02.

[Davo]

It does. Now I just need to get the rest of the parts for an MBSEQ.