TI-89 SpeedUp FAQs

Where can I find a 22pF 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 didn't notice any warming up with 22pF. The problem is that if you use a cap much smaller than 18pF the TI-89 won't work because of the increasing error rate and the fact that the memory is to slow.
Richard Schatz <rschatz@mail.ele.kth.se> wrote: I could not feel any temperature increase at all so I don't think it is a problem. However, one can of course never be sure that there isn't high temperature locally on the chip.
The chance to fry the CPU is very very low and my TI-85 is running for 5 years with the acceleration and it still works! My TI-92 II is running for several months without any problems.

Can I just remove the capacitor?

No this procedure is not recommended with the TI-89 it will cause your calculator to freeze.

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

There might be link problems with accelerated TI-89. Please mail me since I have not yet received any reports about this issue. However if you use a variable capacitor you can set the TI-89 to normal speed and everything should work as usual.

How can I desolder C10?

This is the way how I do it: Take a small screwdriver (like the one to open the calculator). Heat up one side of C10 (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 C10 with the screwdriver. DON'T push too hard and DON'T heat up C10 too long!