Re: A89: Sound
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Re: A89: Sound
On Sat, Nov 18, 2000, Noah Medling wrote:
> >From: Nivek <nivek_ent@yahoo.com>
> >
> >Is there anybody on this list tha knows enough about making sound on a
> >TI-89 calculator that can help me. [...]
>
> I wanna know too!
People have actually written on-calc four channel (midi-) music players with
only this information:
"Sound" (a somewhat controllable electric signal) is generated by first
disabling the byte sender/receiver (by setting $60000C:6), then by frobbing
$60000E:1/0 to change the output. Clear all three bits ($60000C:6 last)
when you are finished. (See my hw doc for details.)
You can have one square wave tone with good frequency precision (lots of CPU
overhead) or bad frequency precision (less CPU overhead, background music
possible, I guess), or one complex sound (such as speech, ...) through PWM
(lots of CPU overhead). Make it two waves/voices/... if you separate left
and right channels. Remember that even the internal speaker in a PC sounds
like a high-quality professional sound system compared to the link port, so
don't expect too much.
The Z80 calc models have "better" link ports for this purpose, the sound
from 68000 calcs is (very) faint. (At least for the PWM sound.)
--
Johan Eilert
References: