Hi Jim, Is the SID Pot ADC the same Pot X any Y that Joysticks or Paddles use? The Actual Transistor on the Pot ADC I didnt know about this and a lot about the SID and I dontvat the time know much about the SID Die, very awesome but if you could point out where the Pot ADC is located on the Die, but I need to try and understand the Pot ADC more too. Thank you for the info on this Jim but I can see its all learning about this particular circuit is needed on my part. Terry Raymond On Tuesday, October 11, 2016, Jim Brain <brain@jbrain.com> wrote: > Terry, before trying to understand the SID ADC, you'll need to learn more > about RC networks, and there are lots of howtos online. > > Trying to understand the C64 behavior without those fundementals will only > frustrate. > > > On a related note: > > The SID POT ADC circuitry needs to drag the line hard to ground for 256 > cycles. NMOS would easily handle this, but it must be a pretty hefty > transistor to ensure it can overcome the current coming from the paddle > resistor. I don't see such a transistor on the 6581 die shots, but it must > be there. What should I look for? > > > jim > > > On October 11, 2016 at 11:57 AM Terry Raymond <traymond20@gmail.com > <javascript:_e(%7B%7D,'cvml','traymond20@gmail.com');>> wrote: > > Hi Jim, > > Please explain (im new to all Electronics) > Input = voltage or Joystick input in this device ? > Cap, I assume the round capacitors. > External Resistor = is this a resistor ladder or 5bit ADC > RC Network ? > > I might look for info on the Commodore files (Bo Zimmerman's site) > Google Digitizers or 5 ADC etc. > I will try to research this more too, but thanks guys for the info. > > Terry Raymond > On Tuesday, October 11, 2016, Jim Brain <brain@jbrain.com > <javascript:_e(%7B%7D,'cvml','brain@jbrain.com');>> wrote: > > Wow, talk about a blast from the past... > > > Since that time, I have confirmed that you get 512 cycles per sample. 256 > with the input tied to ground to completely discharge the cap, and then 256 > left floating to the external resistor can charge the cap via the RC > network. > > > Jim > > > On October 11, 2016 at 10:54 AM groepaz@gmx.net wrote: > > > On Tuesday 11 October 2016, 15:48:16 smf <smf@null.net> wrote: > > Ok, looks like this was answered a long time ago.... > > https://groups.google.com/forum/#!msg/comp.sys.cbm/G0CJgGPLe > i0/MgxDU6GZrz0J > > :) another problem is that teh paddle ADC doesnt translate an external > voltage > to a value, but it measures the resistance of an external resistor - which > makes using it for sampling audio significantly more complex. > > -- > > http://www.hitmen-console.org http://magicdisk.untergrund.net > http://www.pokefinder.org http://ar.pokefinder.org > > Americans always do the right thing, once they have exhausted all other > possibilities. > <Winston Churchill> > > > > Message was sent through the cbm-hackers mailing list > > Message was sent through the cbm-hackers mailing list > > Message was sent through the cbm-hackers mailing list Message was sent through the cbm-hackers mailing listReceived on 2016-10-11 17:00:32
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