TI-H: High-quality sound on the TI

To: ti-hardware@lists.ticalc.org
Subject: TI-H: High-quality sound on the TI
From: Peter Sahlstrom <petegs@bigfoot.com>
Date: Sat, 20 Dec 1997 17:43:24 -0800
Organization: Peter Sahlstrom Productions
References: <349AF6EE.DE921B70@geocities.com>
Reply-To: ti-hardware@lists.ticalc.org


    I just thought of something.  I heard a few days ago about doing
high-speed-output through the TI-LCD using the projector-TI-thingie or
adding another set of connections to the back of the lcd.  One use for this
that was mentioned was for sound on the TI.  The only disadvantages are that
you would have to open up your calc to add on connections, it would make the
TI a little larger, and you wouldn't be able to display anything on the
screen while it was playing a sound.  What if you could make it so that only
one line of pixels on the screen would play sound-it would reduce the sound
possibilities, but you could just have a row of flickering pixels at the
bottom of the screen.  Maybe you could even make it so that you could switch
(on the speaker) between full-screen high quality sound, or
bottom-line-of-the-screen pretty good sound.  I noticed that on the TI-86's
text mode screen, the 127th column of pixels and the 1st column of pixels
both can be accessed on the graph display but not in the text display.  This
would allow you to play sounds while within TI-BASIC programs!  They would
be faster in assembly, of course, but if you can do it in BASIC, well, why
not!
    Secondly, I recall a rectangular port at the top-right (?) of the
TI-92.  I remember hearing that it was for output only-does it just copy the
display screen out or does it receive input from another source?  Either
way, it could be used for output on the TI-92.
    Isn't this exciting!

Jonathan Anderson wrote:

> I had an idea the other day for 16 bit sound on the 92 or any calc with
> a screen connector.  If anyone knows how the TI sends data over the
> link, you could possibly use one or two columns on the screen to
> transmit sound data to a DAC.  A simple sound device could be built with
> some resistors like this (4 bit example):
> 0      1      2      3
> |      |      |      |
> |      |      |      |
> |-/\/\-|-/\/\-|-/\/\-|--- output
>
> You might need another resistor or capacitor in there somewhere.
>
> --
> Jonathan Anderson
> sarlok@geocities.com
>
> "I can't be wrong - my modem is error correcting."

References:

TI-H: 16 bit sound on 92

From: Jonathan Anderson <sarlok@geocities.com>