Sounds like a great idea-- can't wait to do it myself.

What size Torx bit do you need to open the ti-89?

No. 6

//Olle Hedman

How do these people figure out which components to change?

By slowly, methodically destroying their calculators one by one.

:-)

--BlueCalx

At least they know how to do it with a good purpose. I could imagine someone mutilating their TI-89 just for fun. Yeah, they'd need help.
Maybe I'll try this when the warranty on my TI-89 expires. If I screw up, I'll send it back to TI and have them fix it. No problem.

That’s easy when you live in a country with TI support. My TI89 is alone in the middle of the nothing; here there are only 2 or 3 persons with TI calc(I don’t know, I imagine). The rest has Casios and HPs “the best of the world, the 48GX”.When a friend knew my TI89 he just couldn’t believe it. –“Texas Instrumenst? What’s that?”.I remember all the limits I calculated with it...all the derivatives....I cannot hurt my little... So, I keep my TI as a jewel , and I will never make any modifications to it...

So while everyone else is struggling to write systems of equation apps in rpl, you can just use the solve function? I am the only person at my school with an hp(49g). I am one of only two with a casio, and the only one with a 92+. Personally, the 92+ is my favorite, but my 89 and hp49g are close runners-up.

You know, people have known how to do this for ages. Some German store even sells pre-overclocked ti-89's, although it didn't work on my HW 2 (already overclocked?)

Oh well

-Trailblazer

I know it's been 3 years since this was posted, but I have pondered this questino myself. Obviously, it's not random guessing, but I'm sure there's a certain element of trial and error involved (I don't have any actual experience). The way that your calc probably generates a frequency for it's proc is by using a capacitor with an inductor. This combination is what is known as an oscilator and when a modder looks at his calc, he'll prolly look for these two things. Once he finds them, he does some electrical engineering to figure out what new capacitance and resistance might be useful for overclocking. Then he picks up the parts he thinks he needs tries it out and reports it to us.

has anyone else tried this other than me? I used a variable capacitor instead of regular ceramic capacitor. I couldnt find the right variable capacitor at any Radio Shacks, but I did find a 50-pack of assorted capacitors. I tried a few of them, I think the lowest you can go without the calc crashing is either a 15 or 18pF. But i suggest the variable capacitor, cause it allows you to make the calc function "normally" again. Try it if youre brave enough to fiddle around with it, its alot of fun!:P

Or you could use two capacitors and a switch to select Normal speed mode or Turbo speed mode.

can you switch on the fly? or have to have it off to do that?

It has to be off, at least mine did, or else it causes some problems when the switch is being switched because for a split second it has no capacitor at all connected and that causes the RAM to not be able to keep up with the processor, so you end up having to hit second+left+right+on, or pull the batteries.

Unless you have lightning quick hands(like myself :) ) and can flip that switch faster than the speed of light. Then it's possible. :)

-GordonChil

Use a flip toggle switch. You can switch capacitance on the fly w/o weird stuff happening. Very useful to add "nitro" to long and tedious calculations such as Laplacians and Differential equations. Mine works flawlessly. BTW, why doesn't some chump make a ti89 emulator for PDA's, then we wouldn't need to fiddle w/ hardware.

Yeah you can. It requires special wireing to make it work tho, other wise somthing bad might happen. if someones realy intrested email me and i'll tell you how to do it.

Also I forgot to mention, that the wiring for on-the-fly switching dosen't make you remove the origonal capictor.

I like the idea of the variable capacitor b/c you can fine tune the speed to what you want. Some games go crazy when you have it cranked up. but the slide switch is easier to use, especially if you mount it on the side so you can switch it whenever.

I overclocked my calc to ~17MHz with an 18pf capacitor, any lower of a capacitor that I used caused the RAM to not be able to keep up with the processor. I switched the capacitors about 10 or 20 times it seems, and I never screwed it up once (very limited prior experience with a soldering iron too) so if you have any kind of experience at all then you should have no problem doing it. Mine is a HW1 though, I don't know if they HW2 one is harder or not.

Forgot to mention that I put a switch on the first time I did it and it worked beautifully. It would only run ~15.5Mhz that way though, because I had to use a larger capacitor. So I said hell with it and just put in the 18pf capacitor so it would go 17Mhz.... most games are screwy like this, Phoenix and TIchess are a different story; they kick ass with the overclocked processor. I only use the 89 mainly for calculus work anyways.

Well I kind of, um, burnt the board of my 83 trying to overclock... I think I have my soldering iron turned up too high. Now I have to connect in all other places, look at the board under microscope to find connections, etc. My soder doesn't stick too well either.