TI 83+ Overclock

[tayexdrums]

I recently found an old TI 83+ graphing calculator and decided to try and overclock it just for the heck of it. Many websites I found showed that you remove one capacitor and replace it with a different value. Here is one site...http://www.ftp83plus.net/overclocA.htm#S. However, the circuit board used on the website is a different version of the circuit board which is inside my TI 83+. When I found this out, I thought I would try to find a way around it. I tried to find a datasheet on the CPU that is inside of the calculator but was not able to find one. I wanted to find the clock pin on the processor (if that is what the pin would be labeled) and change the capacitor value that is wired to it. Since I could not find a datasheet, I am now back to square one. If anyone has overclocked a TI 83+ or has any advice on what I could do, I would appreciate it=]

Below are included photos:
TI 83+



back panel removed showing exposed foil



back panel and foil removed exposing circuit board



close up shot of what I am pretty sure is the CPU



close up shot of what I believe might be the RAM or ROM



close up shot of but thought it might be helpful

[Time]

Yep.  Theres all kind of cool mods and home made accessories you can make for the TI line of graphing calcs.  I used to do this back in the day when I was in highschool (12 years ago).  I actually did this mod to my 83+.  Modding TI calcs is what got me interested in EE in general.  As it was 12 years ago and my calc is also 12 years old I cant really help you, sorry :/  but it is doable!

[tayexdrums]

Woww.lol
Well, does what I'm trying to do sound like what you did?

[Time]

Oh, yea its just a cap you replace. 

[tayexdrums]

Question is...which one?lol

[johnmx]

I did that on both of my TI-92 calculators. So I cannot help you. But I did something better, I’ve replaced the ceramic capacitor with a variable capacitor. Thus I can change the clock speed every time I want. This is very important because if you double the frequency you also double the power consumption, and the batteries will last half.

I’ve done this mod because I wrote some programs/games for the TI using their programming language, which is very slow when running. But you don’t need to do it if you program in assembly. Actually assembly programs will become too fast to be used with the TI overclocked.

So for final conclusion, I recommend you to not modify the clock frequency.

[tayexdrums]

That's awesome, why didn't I think of that!
I'll try that.

[Semantics]

Question is...which one?lol

You know what they say:
Turning the screw.... $5
Knowing which screw to turn.... $195