[Coco] Project Sneak Peek
zippster278 at gmail.com
Wed Jul 20 12:34:57 EDT 2016
I would think running the output through a low-pass filter and using an op-amp
circuit similar to what the Orch90 uses would give good results with the CoCo
SND input. Though that is adding several additional components of course.
The 4558 is still produced and available in an SMT package. It’s just a GP op-amp.
> On Jul 19, 2016, at 11:30 PM, Darren A <mechacoco at gmail.com> wrote:
> On Tue, Jul 19, 2016 at 3:31 PM, Nick Marentes wrote:
>> On 20/07/2016 6:43 AM, Zippster wrote:
>>> With the addition of an analog low-pass filter, yes.
>>> Otherwise they are square waves.
>>> - Ed
>> I assume that the PWM functionality is built into the microcontroller for
>> the ability to control things like stepper motors
>> Sounds cool but I wonder how many CoCo enthusiasts would actually do this.
>> Is there an option in the controller to vary the amplitude of the PWM or
>> better still, a DAC to dump data from the RAM to the sound output for
>> enhanced game sounds?
>> I also assume that any PWM sound will not be mixed with the CoCo's 6-bit
>> (So many questions.) :)
> Sound generating hardware/software is not my area of expertise. I just
> adapted the arduino code referenced below so it could play samples from
> files on an SD card instead of from the MCU flash memory:
> The SND input on the CoCo cartridge port is not mixed with output from the
> 6-bit DAC, but can be mixed with the single-bit sound output.
> - Darren
> Coco mailing list
> Coco at maltedmedia.com
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