Re: A89: Sound Progs

[Prev][Next][Index][Thread]

Re: A89: Sound Progs


Not bad, but here's a better one. =)

The TI-83,86,89 and 92 all have auto uploading.  That is, the TI Winlink
software can upload files to these calcs without them being in receive mode.
How does this work?  Well the TI-OS normally checks the linkport in an
interrupt to see what's going on.  Since the headphones don't comply with
the TI link protocol, the TI-OS constantly times-out every time it tries to
check the port thus slowing the calc down immensly.  Plug in a set of
headphones when a program is running and you may not have this problem.
This, of course, depends on your calc and the program running.  If you have
the 83/86 then the TI-OS checks the linkport everytime GET_KEY is called.
If a program only uses direct input, then you'll have no problem.  The 89/92
have an interrupt-based check and so it probably will take more than just a
program running to solve the problem.

To prove my point, try plugging in a set of headphones while playing SQRXZ
on the TI-83 or TI-86.  No slowdown.  Quit the game and then you get
slowdown.  Doh!  The general rule of thumb for using sound with your calc is
to plug in the headphones AFTER you start the sound-using program.

-Justin Karneges [Infiniti]

> That's a great answer... how about a more descriptive one?
>
> The 89's link port is powered by the 4AAA batteries, so when you plug in
> unpowered headphones, this really cut power from the rest of the calc,
> slowing it down.  If you plug powered speakers into the 89 port, then you
> won't notice this slow down as much.
>
> -Miles Raymond      EML: m_rayman@bigfoot.com
> ICQ: 13217756       IRC: Killer2        AIM: MRayMan
> http://www.bigfoot.com/~m_rayman/
>
> ----- Original Message -----
> From: Patrick Sweeney <psweeney@geocities.com>
> To: <assembly-89@lists.ticalc.org>
> Sent: Thursday, April 15, 1999 5:44 PM
> Subject: Re: A89: Sound Progs
>
>
> > No it isn't.
> >
> > Wingman627@aol.com wrote:
> >
> > > Is it abnormal that when I plug headphones into my calc that it
> "freezes"?
>
>
Follow-Ups: References: