Re: TI-H: Stereo sound

To: ti-hardware@lists.ticalc.org
Subject: Re: TI-H: Stereo sound
From: tsaimelv@pilot.msu.edu (Mel Tsai)
Date: Sun, 16 Nov 1997 02:58:38 GMT
In-Reply-To: <01bcf220$0172b060$c139d2cc@pacific.san.rr.com>
References: <01bcf220$0172b060$c139d2cc@pacific.san.rr.com>
Reply-To: ti-hardware@lists.ticalc.org

>Does anyone else find this exciting?  I mean, stereo 
>sound for the TI-92 has been created.  One thing bothers me though, 
>and that is the lock-up that is experianced.  There has to be a better 
>way to do this that would not make it lock up.  Has anyone tried two 
>membranes, or piezo buzzers (thats what I used for mono sound)?  Maybe 
>its just the headphones.  Maybe some diodes placed somewhere along the 
>line?

A couple months ago when bryan turner (and me) were researching
linkport control on the 92 we noticed that when you reconfigure the
port to allow for direct linkport writing (and hence stereo sound)
whenever you attempted to write data to the port very fast it would
lock up.  Bryan Rittmeyer (EuP creator) also noticed this when he was
creating the eup protocol.  Currently we do not know how to fix this,
although I have a strong suspicion that there is some other bit that
must be set to get the 92 to ignore this condition.  

Funny that this is only now coming to light when we knew about stereo
sound over 3 months ago...

-Mel
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-The TI-Memory Expansion Homepage
-http://www.egr.msu.edu/~tsaimelv/expander.htm

References:

TI-H: Stereo sound

From: "scross" <scross@san.rr.com>