Topic 1: Internal Speakers

How about attaching a pair of internal speakers to the TI-83+?
I'm thinking of maybe a way to switch back and forward between the linkport headphones as well...

I think you mean attach; why would you do any attacking of a pair of speakers? They never did anything to you.

So, there's a whole bunch of different ways to do this. First, you could just use headphones with a 2.5mm -> 3.5mm stereo adapter. Second, you could use an audio patch cable with a 2.4mm -> 3.5mm stereo adapter to connect your calculator to the line-in jack of a stereo, amplifier, or computer, then just listen that way. Those all either use no amplifier or some existing amplifier. If you want to have an actual discrete amplifier and speakers with your calculator, the options are a bit more complex.

You can either use a magnetic speaker element of some kind, or a piezo speaker. Either way, you'll need a small transistor amplifier, which is basically just a 2N2222 transistor and a potentiometer. The hard part is that you'll also need a 5V or 6V supply. Therefore, you could built this internal to your calculator, in all the space behind the main PCB, and use the calculator's batteries, or make it external and use three or four AAs or AAAs for your power source. If you make it internal, you'll want to have a 4-position SPST DIP switch bank, two to disconnect the two data lines from the amplifier, and a third to disconnect +V from the amplifier. You'd have the fourth switch in the DIP package left over for future projects like backlighting.

I'll post a schematic / diagram of the amplifier schematic if anyone's interested.

the easiest way to do it is with the headphone thing. There isn't ANY room in a 83 for speakers. They are really cramped inside. I think a better amplifier, Kerm, would be a darlington pair. They amplify a lot more than just a single transistor. If you can find a SUPER thin speaker, or a piezo buzzer thing, that would work in the calc. And you would have a really small speaker anyway, plus through the plastic? It wouldn't be very loud. You could always drill a ton of little holes though. Anyway, just my advice.

It doesn't even have to be a super-thin speaker in my opinion; even something 3/8" thick would be fine in my view. Yeah, a Darlington pair would be more powerful, but I was thinking it terms of the tradeoff between volume and battery drain.

It's been a while since Kerm responded... but the speaker can't fit in that tiny space between the battery holder and the screen, (unless its less than like 3/4" diameter...). There would be a switch in line from the link port to stop the drain from the darlington pair. And the pair is the only way that the speaker would be loud enough to hear through any amount of case.

Nono, behind the screen there's 1/4" depth for about 1" diameter, or a minimum of 1/8" to 3/16" depth for about 2" diameter.

Ah, but you said 3/8" thick speaker...

Aight, I was playing a little fast and loose with dimensions. Actually, if you remove the LCD weight (a useless piece of metal) you can get another 1/8" at least, as I did on the UltCalc2. Either way, you can absolutely fit a thin speaker of some sort between the LCD and the back of the case, with grilles on the back of the case.