TI-82 SpeedUp FAQs

Does this work with all TI-82 versions?

I tested it on a TI-82 with ROM version 19. The hardware is more or less the same on all TI-82s. This procedure should work with all TI-82 versions!

Where can I find a 15pF capacitor?

Clegg [Clegg@newrock.com] wrote:
I have found that every Radio Shack in the US so far has a pack of caps called a pF pack and it has a very huge amount of misc. caps from 1 to 33pF. (Catalog No. 272-806)

What is the smallest size cap you could use without heating up the CPU to hot?

The heating up is not a problem in this case. I tried to speed up the TI-82 three time but this caused the TI to produce some errors (especially display errors like lines across the screen). Using a 15pF capacitor speeds up the TI by about two times, and I didn't notice any problem at this speed. If you do, please let me know.

Can I just remove the capacitor?

No this procedure is not recommended with the TI-82 it will cause your calculator to freeze.

Does the link work, if the TIs run at different speed?

There is no problem to connect a slow to a fast TI, since the two connected TIs chose a speed, which both can support. You will notice that the transmission speed changes if one of the calculators isn't accelerated or if the batteries are low.
My computer link from Texas Instruments works too, however Pasi Lassila (pas1@freenet.hut.fi) told me that he had problems with a TI-85 calculator and the parallel link (this is the only report I have about problems with links and accelerated calculators). I don't know if there's a problem with the parallel link and the TI-82.

How can I desolder C7?

This is the way how I do it: Take a small screwdriver (like the one to open the calculator). Heat up one side of C7 (not longer than one second), quickly change to the other side and heat it up, change back and so on while you are trying to push away C7 with the screwdriver. DON'T push too hard and DON'T heat up C13 too long! Do not burn the cable that connects the display board to the main board!

Is it possible to do this with a TI-81?

I had a TI-81 too and in fact I tried to accelerate the TI-81 first. The location of the capacitor is on the left side of the main board beside U4. It's named C9 (just like on the TI-85). I included a ASCII-picture, hope it's clear ;-)

Main board:
  +-----------------------------------------------------      
  |                                 C  C C  R11               
  |                                 8 11 9           C7       
  |  ~~~~~~~~~~~~~~~~~~~~          +------------+             
  |  ~                   ~         |            |             
  |  ~                   ~         |            |             
  |  ~                   ~         |     U4     |             
  |  ~                   ~         |            |             
  |  ~                   ~         +------------+             
  |  ~   Batteries       ~                                    
  |  ~                   ~                                    
  |  ~                   ~                                    
  |  ~                   ~                                    
  |  ~                   ~     +----+        +----+           
  |  ~                   ~     |    |        |    |           
  |  ~                   ~     | U6 |        | U5 |           
  |  ~                   ~     |    |        |    |           
  |  ~~~~~~~~~~~~~~~~~~~~      +----+        +----+           
  |                                                           
  +-----------------------------------------------------      
 

I managed to accelerate the keyboard response of the TI-82 too (you have to replace C6 with something between 150pF and 500pF)