[sdiy] SID questions...

[Ken Stone]

I can't answer all of these, but the X and Y analog inputs are most likely
how they were handling the "paddle" inputs. Vic 20s and C64s both worked
with switch joysticks AND pot based paddles.

Ken
 

>while we're on this topic - I've found sid chip and 8255 so I'm
>considering
>building parallel sid, but some things puzzle me:
>
>1. There's missing clock input to sid at the schematic, do I need to
>make
>some with logic gates or something or you pull clock signal from
>somewhere
>else?
>
>2. There are X and Y analog inputs, which measure RC constant and
>convert
>analog to digital for controllers. Now, I can't find info WHAT they do 
>control inside the sid? I thought to put two pots on front panel for
>real time editing, or some simple circuit that will convert CV to 
>some RC time constant (some OTA app?).
>
>3. External input - is it operational with the program given, it'd
>be nice use it as ext processor too, just to make simple buffer
>to input, or even some little pramp.
>
>4. I'll make some single supply buffer at sid output, C64 used single
>transistor emiter foll. (noisy?), but also I remember seeing somewhere
>at Commodore sites one app that used 15kHz LPF made from lm324 at
>the output. Good idea?
>
>
>I've read sid datasheets and that sidtech pages online but still can't
>figure these things...
>
>
>Thanks,
>
>
>marjan
>
>
_______________________________________________________________________
Ken Stone   sasami at blaze.net.au  
Modular Synth <http://kato.sai.com.au/catgirl/synth/>
Catgirl Paradise <http://www.anime.net/~kens/>
Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>