>Clay and I are quite serious. I started poking at the design about two
>months ago (just before I got sucked into the time sink of 70's B&W
>raster games, but that's my own fault..) and I'm really interested
>now that two different designs on PC boards were given to me.
And I've got the Sega stuff pretty much wrapped up now, so it's this or
Nightmare next... :-)
>I just looked at the schematics, and it turns out the design that used
>DAC80's used a 4016 analog switch instead of the National LF part.
>I'll have to trace out the other design that used National DAC1221's
>and an LF switch.
Anybody know why Atari got away from the 4016 and went with the LF13201 in
the AVG games? My guess was that the series resistance of the 4016 was too
high and gave them problems with zero'ing the caps in the integrator...
Seems like I saw something (somewhere) that used a bunch of 4066's or
4016's in parallel-- presumably just to lower the series resistance.
4066's are pretty cheap and plentiful compared to their LF13xxx bretheren.
-Clay
Clayton N. Cowgill Engineering Manager
_______________________________________________________________________
/\ Diamond Multimedia Systems, Inc. clay@supra.com
\/ Communications Division http://www.supra.com/
Received on Mon Dec 1 16:31:36 1997
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