cuda@ihlpg.UUCP (Nelson) (12/23/86)
Does anyone know how the SID chip does the A/D conversion? Since you have to use a specific maximum time constant, and changing the value of the pot effects the time constant it would seem that some type of timing is done and not a true A/D (voltage) measurement. Have any of you tried using a fixed RC ratio and varying the voltage? I would like to use the pot pins for voltage measurement but don't know how to fake the system out. Thanks for all the help. Mike Nelson ihlpg!cuda AT&T Bell Labs
maryr@well.UUCP (Mary C Rinaldi) (01/11/87)
In article <2668@ihlpg.UUCP> cuda@ihlpg.UUCP (Nelson) writes: >Does anyone know how the SID chip does the A/D conversion? Since >you have to use a specific maximum time constant, and changing the >value of the pot effects the time constant it would seem that some >type of timing is done and not a true A/D (voltage) measurement. >Have any of you tried using a fixed RC ratio and varying the voltage? >I would like to use the pot pins for voltage measurement but don't >know how to fake the system out. > >Thanks for all the help. > >Mike Nelson >ihlpg!cuda >AT&T Bell Labs I've began experimenting with the joystick ports on my C64. I just bought some paddles to tear apart to look at. I also bought a 500k ohm pentiometer which is almost the same as the one in the paddles(470k ohm) Ill post here as soon as i figure it out, i want to hook up a thermistor and a phototransistor to it and use it in a lab.